Merge pull request #4554 from thaJeztah/update_engine

vendor: github.com/docker/docker 06499c52e2b1 (v25.0.0-dev)

vendor.mod

@@ -13,7 +13,7 @@ require (
 	github.com/creack/pty v1.1.18
 	github.com/distribution/reference v0.0.0-20230830145923-e42074f83a9c
 	github.com/docker/distribution v2.8.2+incompatible
-	github.com/docker/docker v24.0.0-rc.2.0.20230905130451-032797ea4bcb+incompatible // master (v25.0.0-dev)
+	github.com/docker/docker v24.0.0-rc.2.0.20230907222536-06499c52e2b1+incompatible // master (v25.0.0-dev)
 	github.com/docker/docker-credential-helpers v0.8.0
 	github.com/docker/go-connections v0.4.0
 	github.com/docker/go-units v0.5.0
@@ -55,6 +55,9 @@ require (
 	github.com/docker/go v1.5.1-1.0.20160303222718-d30aec9fd63c // indirect
 	github.com/docker/go-events v0.0.0-20190806004212-e31b211e4f1c // indirect
 	github.com/docker/go-metrics v0.0.1 // indirect
+	github.com/felixge/httpsnoop v1.0.3 // indirect
+	github.com/go-logr/logr v1.2.3 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/golang/protobuf v1.5.3 // indirect
 	github.com/gorilla/mux v1.8.0 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
@@ -71,6 +74,11 @@ require (
 	github.com/xeipuuv/gojsonpointer v0.0.0-20190905194746-02993c407bfb // indirect
 	github.com/xeipuuv/gojsonreference v0.0.0-20180127040603-bd5ef7bd5415 // indirect
 	go.etcd.io/etcd/raft/v3 v3.5.6 // indirect
+	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.29.0 // indirect
+	go.opentelemetry.io/otel v1.4.1 // indirect
+	go.opentelemetry.io/otel/internal/metric v0.27.0 // indirect
+	go.opentelemetry.io/otel/metric v0.27.0 // indirect
+	go.opentelemetry.io/otel/trace v1.4.1 // indirect
 	golang.org/x/crypto v0.2.0 // indirect
 	golang.org/x/mod v0.9.0 // indirect
 	golang.org/x/net v0.10.0 // indirect

vendor.sum

@@ -25,6 +25,7 @@ github.com/bugsnag/osext v0.0.0-20130617224835-0dd3f918b21b h1:otBG+dV+YK+Soembj
 github.com/bugsnag/osext v0.0.0-20130617224835-0dd3f918b21b/go.mod h1:obH5gd0BsqsP2LwDJ9aOkm/6J86V6lyAXCoQWGw3K50=
 github.com/bugsnag/panicwrap v0.0.0-20151223152923-e2c28503fcd0 h1:nvj0OLI3YqYXer/kZD8Ri1aaunCxIEsOst1BVJswV0o=
 github.com/bugsnag/panicwrap v0.0.0-20151223152923-e2c28503fcd0/go.mod h1:D/8v3kj0zr8ZAKg1AQ6crr+5VwKN5eIywRkfhyM/+dE=
+github.com/cenkalti/backoff/v4 v4.1.2 h1:6Yo7N8UP2K6LWZnW94DLVSSrbobcWdVzAYOisuDPIFo=
 github.com/certifi/gocertifi v0.0.0-20191021191039-0944d244cd40/go.mod h1:sGbDF6GwGcLpkNXPUTkMRoywsNa/ol15pxFe6ERfguA=
 github.com/certifi/gocertifi v0.0.0-20200922220541-2c3bb06c6054/go.mod h1:sGbDF6GwGcLpkNXPUTkMRoywsNa/ol15pxFe6ERfguA=
 github.com/cespare/xxhash/v2 v2.2.0 h1:DC2CZ1Ep5Y4k3ZQ899DldepgrayRUGE6BBZ/cd9Cj44=
@@ -52,8 +53,8 @@ github.com/distribution/reference v0.0.0-20230830145923-e42074f83a9c/go.mod h1:B
 github.com/docker/distribution v2.7.1+incompatible/go.mod h1:J2gT2udsDAN96Uj4KfcMRqY0/ypR+oyYUYmja8H+y+w=
 github.com/docker/distribution v2.8.2+incompatible h1:T3de5rq0dB1j30rp0sA2rER+m322EBzniBPB6ZIzuh8=
 github.com/docker/distribution v2.8.2+incompatible/go.mod h1:J2gT2udsDAN96Uj4KfcMRqY0/ypR+oyYUYmja8H+y+w=
-github.com/docker/docker v24.0.0-rc.2.0.20230905130451-032797ea4bcb+incompatible h1:1UUPAB9PAPUbM10+qIKPL5tKZ+VAddWgbQUf+x1QBfI=
+github.com/docker/docker v24.0.0-rc.2.0.20230907222536-06499c52e2b1+incompatible h1:wSeDxA5kbar3It3D8VVHH50TVWwEs7sAT+UO3UtFtlU=
-github.com/docker/docker v24.0.0-rc.2.0.20230905130451-032797ea4bcb+incompatible/go.mod h1:eEKB0N0r5NX/I1kEveEz05bcu8tLC/8azJZsviup8Sk=
+github.com/docker/docker v24.0.0-rc.2.0.20230907222536-06499c52e2b1+incompatible/go.mod h1:eEKB0N0r5NX/I1kEveEz05bcu8tLC/8azJZsviup8Sk=
 github.com/docker/docker-credential-helpers v0.8.0 h1:YQFtbBQb4VrpoPxhFuzEBPQ9E16qz5SpHLS+uswaCp8=
 github.com/docker/docker-credential-helpers v0.8.0/go.mod h1:UGFXcuoQ5TxPiB54nHOZ32AWRqQdECoh/Mg0AlEYb40=
 github.com/docker/go v1.5.1-1.0.20160303222718-d30aec9fd63c h1:lzqkGL9b3znc+ZUgi7FlLnqjQhcXxkNM/quxIjBVMD0=
@@ -71,6 +72,9 @@ github.com/docker/libtrust v0.0.0-20160708172513-aabc10ec26b7 h1:UhxFibDNY/bfvqU
 github.com/docker/libtrust v0.0.0-20160708172513-aabc10ec26b7/go.mod h1:cyGadeNEkKy96OOhEzfZl+yxihPEzKnqJwvfuSUqbZE=
 github.com/dvsekhvalnov/jose2go v0.0.0-20170216131308-f21a8cedbbae/go.mod h1:7BvyPhdbLxMXIYTFPLsyJRFMsKmOZnQmzh6Gb+uquuM=
 github.com/erikstmartin/go-testdb v0.0.0-20160219214506-8d10e4a1bae5/go.mod h1:a2zkGnVExMxdzMo3M0Hi/3sEU+cWnZpSni0O6/Yb/P0=
+github.com/felixge/httpsnoop v1.0.2/go.mod h1:m8KPJKqk1gH5J9DgRY2ASl2lWCfGKXixSwevea8zH2U=
+github.com/felixge/httpsnoop v1.0.3 h1:s/nj+GCswXYzN5v2DpNMuMQYe+0DDwt5WVCU6CWBdXk=
+github.com/felixge/httpsnoop v1.0.3/go.mod h1:m8KPJKqk1gH5J9DgRY2ASl2lWCfGKXixSwevea8zH2U=
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
 github.com/fvbommel/sortorder v1.0.2 h1:mV4o8B2hKboCdkJm+a7uX/SIpZob4JzUpc5GGnM45eo=
 github.com/fvbommel/sortorder v1.0.2/go.mod h1:uk88iVf1ovNn1iLfgUVU2F9o5eO30ui720w+kxuqRs0=
@@ -78,7 +82,11 @@ github.com/getsentry/raven-go v0.2.0/go.mod h1:KungGk8q33+aIAZUIVWZDr2OfAEBsO49P
 github.com/go-kit/kit v0.8.0/go.mod h1:xBxKIO96dXMWWy0MnWVtmwkA9/13aqxPnvrjFYMA2as=
 github.com/go-logfmt/logfmt v0.3.0/go.mod h1:Qt1PoO58o5twSAckw1HlFXLmHsOX5/0LbT9GBnD5lWE=
 github.com/go-logfmt/logfmt v0.4.0/go.mod h1:3RMwSq7FuexP4Kalkev3ejPJsZTpXXBr9+V4qmtdjCk=
+github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
 github.com/go-logr/logr v1.2.3 h1:2DntVwHkVopvECVRSlL5PSo9eG+cAkDCuckLubN+rq0=
+github.com/go-logr/logr v1.2.3/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
+github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
 github.com/go-sql-driver/mysql v1.5.0 h1:ozyZYNQW3x3HtqT1jira07DN2PArx2v7/mN66gGcHOs=
 github.com/go-sql-driver/mysql v1.5.0/go.mod h1:DCzpHaOWr8IXmIStZouvnhqoel9Qv2LBy8hT2VhHyBg=
 github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
@@ -102,6 +110,7 @@ github.com/google/certificate-transparency-go v1.0.10-0.20180222191210-5ab67e519
 github.com/google/certificate-transparency-go v1.1.4 h1:hCyXHDbtqlr/lMXU0D4WgbalXL0Zk4dSWWMbPV8VrqY=
 github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.7/go.mod h1:n+brtR0CgQNWTVd5ZUFpTBC8YFBDLK/h/bpaJ8/DtOE=
 github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
 github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
@@ -110,6 +119,7 @@ github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510/go.mod h1:pupxD2MaaD3
 github.com/gorilla/mux v1.7.0/go.mod h1:1lud6UwP+6orDFRuTfBEV8e9/aOM/c4fVVCaMa2zaAs=
 github.com/gorilla/mux v1.8.0 h1:i40aqfkR1h2SlN9hojwV5ZA91wcXFOvkdNIeFDP5koI=
 github.com/gorilla/mux v1.8.0/go.mod h1:DVbg23sWSpFRCP0SfiEN6jmj59UnW/n46BH5rLB71So=
+github.com/grpc-ecosystem/grpc-gateway v1.16.0 h1:gmcG1KaJ57LophUzW0Hy8NmPhnMZb4M0+kPpLofRdBo=
 github.com/hailocab/go-hostpool v0.0.0-20160125115350-e80d13ce29ed h1:5upAirOpQc1Q53c0bnx2ufif5kANL7bfZWcc6VJWJd8=
 github.com/hailocab/go-hostpool v0.0.0-20160125115350-e80d13ce29ed/go.mod h1:tMWxXQ9wFIaZeTI9F+hmhFiGpFmhOHzyShyFUhRm0H4=
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
@@ -261,6 +271,23 @@ github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9dec
 go.etcd.io/etcd/client/pkg/v3 v3.5.6/go.mod h1:ggrwbk069qxpKPq8/FKkQ3Xq9y39kbFR4LnKszpRXeQ=
 go.etcd.io/etcd/raft/v3 v3.5.6 h1:tOmx6Ym6rn2GpZOrvTGJZciJHek6RnC3U/zNInzIN50=
 go.etcd.io/etcd/raft/v3 v3.5.6/go.mod h1:wL8kkRGx1Hp8FmZUuHfL3K2/OaGIDaXGr1N7i2G07J0=
+go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.29.0 h1:SLme4Porm+UwX0DdHMxlwRt7FzPSE0sys81bet2o0pU=
+go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.29.0/go.mod h1:tLYsuf2v8fZreBVwp9gVMhefZlLFZaUiNVSq8QxXRII=
+go.opentelemetry.io/otel v1.4.0/go.mod h1:jeAqMFKy2uLIxCtKxoFj0FAL5zAPKQagc3+GtBWakzk=
+go.opentelemetry.io/otel v1.4.1 h1:QbINgGDDcoQUoMJa2mMaWno49lja9sHwp6aoa2n3a4g=
+go.opentelemetry.io/otel v1.4.1/go.mod h1:StM6F/0fSwpd8dKWDCdRr7uRvEPYdW0hBSlbdTiUde4=
+go.opentelemetry.io/otel/exporters/otlp/internal/retry v1.4.1 h1:imIM3vRDMyZK1ypQlQlO+brE22I9lRhJsBDXpDWjlz8=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.4.1 h1:WPpPsAAs8I2rA47v5u0558meKmmwm1Dj99ZbqCV8sZ8=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.4.1 h1:8qOago/OqoFclMUUj/184tZyRdDZFpcejSjbk5Jrl6Y=
+go.opentelemetry.io/otel/internal/metric v0.27.0 h1:9dAVGAfFiiEq5NVB9FUJ5et+btbDQAUIJehJ+ikyryk=
+go.opentelemetry.io/otel/internal/metric v0.27.0/go.mod h1:n1CVxRqKqYZtqyTh9U/onvKapPGv7y/rpyOTI+LFNzw=
+go.opentelemetry.io/otel/metric v0.27.0 h1:HhJPsGhJoKRSegPQILFbODU56NS/L1UE4fS1sC5kIwQ=
+go.opentelemetry.io/otel/metric v0.27.0/go.mod h1:raXDJ7uP2/Jc0nVZWQjJtzoyssOYWu/+pjZqRzfvZ7g=
+go.opentelemetry.io/otel/sdk v1.4.1 h1:J7EaW71E0v87qflB4cDolaqq3AcujGrtyIPGQoZOB0Y=
+go.opentelemetry.io/otel/trace v1.4.0/go.mod h1:uc3eRsqDfWs9R7b92xbQbU42/eTNz4N+gLP8qJCi4aE=
+go.opentelemetry.io/otel/trace v1.4.1 h1:O+16qcdTrT7zxv2J6GejTPFinSwA++cYerC5iSiF8EQ=
+go.opentelemetry.io/otel/trace v1.4.1/go.mod h1:iYEVbroFCNut9QkwEczV9vMRPHNKSSwYZjulEtsmhFc=
+go.opentelemetry.io/proto/otlp v0.12.0 h1:CMJ/3Wp7iOWES+CYLfnBv+DVmPbB+kmy9PJ92XvlR6c=
 go.uber.org/atomic v1.7.0/go.mod h1:fEN4uk6kAWBTFdckzkM89CLk9XfWZrxpCo0nPH17wJc=
 go.uber.org/multierr v1.6.0/go.mod h1:cdWPpRnG4AhwMwsgIHip0KRBQjJy5kYEpYjJxpXp9iU=
 go.uber.org/zap v1.17.0/go.mod h1:MXVU+bhUf/A7Xi2HNOnopQOrmycQ5Ih87HtOu4q5SSo=

vendor/github.com/docker/docker/client/client.go

@@ -56,6 +56,8 @@ import (
 	"github.com/docker/docker/api/types/versions"
 	"github.com/docker/go-connections/sockets"
 	"github.com/pkg/errors"
+	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
+	"go.opentelemetry.io/otel/trace"
 )
 
 // DummyHost is a hostname used for local communication.
@@ -123,6 +125,12 @@ type Client struct {
 
 	// negotiated indicates that API version negotiation took place
 	negotiated bool
+
+	tp trace.TracerProvider
+
+	// When the client transport is an *http.Transport (default) we need to do some extra things (like closing idle connections).
+	// Store the original transport as the http.Client transport will be wrapped with tracing libs.
+	baseTransport *http.Transport
 }
 
 // ErrRedirect is the error returned by checkRedirect when the request is non-GET.
@@ -188,6 +196,12 @@ func NewClientWithOpts(ops ...Opt) (*Client, error) {
 		}
 	}
 
+	if tr, ok := c.client.Transport.(*http.Transport); ok {
+		// Store the base transport before we wrap it in tracing libs below
+		// This is used, as an example, to close idle connections when the client is closed
+		c.baseTransport = tr
+	}
+
 	if c.scheme == "" {
 		// TODO(stevvooe): This isn't really the right way to write clients in Go.
 		// `NewClient` should probably only take an `*http.Client` and work from there.
@@ -201,9 +215,24 @@ func NewClientWithOpts(ops ...Opt) (*Client, error) {
 		}
 	}
 
+	c.client.Transport = otelhttp.NewTransport(
+		c.client.Transport,
+		otelhttp.WithTracerProvider(c.tp),
+		otelhttp.WithSpanNameFormatter(func(_ string, req *http.Request) string {
+			return req.Method + " " + req.URL.Path
+		}),
+	)
+
 	return c, nil
 }
 
+func (cli *Client) tlsConfig() *tls.Config {
+	if cli.baseTransport == nil {
+		return nil
+	}
+	return cli.baseTransport.TLSClientConfig
+}
+
 func defaultHTTPClient(hostURL *url.URL) (*http.Client, error) {
 	transport := &http.Transport{}
 	err := sockets.ConfigureTransport(transport, hostURL.Scheme, hostURL.Host)
@@ -216,20 +245,11 @@ func defaultHTTPClient(hostURL *url.URL) (*http.Client, error) {
 	}, nil
 }
 
-// tlsConfig returns the TLS configuration from the client's transport.
-// It returns nil if the transport is not a [http.Transport], or if no
-// TLSClientConfig is set.
-func (cli *Client) tlsConfig() *tls.Config {
-	if tr, ok := cli.client.Transport.(*http.Transport); ok {
-		return tr.TLSClientConfig
-	}
-	return nil
-}
-
 // Close the transport used by the client
 func (cli *Client) Close() error {
-	if t, ok := cli.client.Transport.(*http.Transport); ok {
+	if cli.baseTransport != nil {
-		t.CloseIdleConnections()
+		cli.baseTransport.CloseIdleConnections()
+		return nil
 	}
 	return nil
 }
@@ -356,6 +376,20 @@ func ParseHostURL(host string) (*url.URL, error) {
 	}, nil
 }
 
+func (cli *Client) dialerFromTransport() func(context.Context, string, string) (net.Conn, error) {
+	if cli.baseTransport == nil || cli.baseTransport.DialContext == nil {
+		return nil
+	}
+
+	if cli.baseTransport.TLSClientConfig != nil {
+		// When using a tls config we don't use the configured dialer but instead a fallback dialer...
+		// Note: It seems like this should use the normal dialer and wrap the returned net.Conn in a tls.Conn
+		// I honestly don't know why it doesn't do that, but it doesn't and such a change is entirely unrelated to the change in this commit.
+		return nil
+	}
+	return cli.baseTransport.DialContext
+}
+
 // Dialer returns a dialer for a raw stream connection, with an HTTP/1.1 header,
 // that can be used for proxying the daemon connection. It is used by
 // ["docker dial-stdio"].
@@ -363,10 +397,8 @@ func ParseHostURL(host string) (*url.URL, error) {
 // ["docker dial-stdio"]: https://github.com/docker/cli/pull/1014
 func (cli *Client) Dialer() func(context.Context) (net.Conn, error) {
 	return func(ctx context.Context) (net.Conn, error) {
-		if transport, ok := cli.client.Transport.(*http.Transport); ok {
+		if dialFn := cli.dialerFromTransport(); dialFn != nil {
-			if transport.DialContext != nil && transport.TLSClientConfig == nil {
+			return dialFn(ctx, cli.proto, cli.addr)
-				return transport.DialContext(ctx, cli.proto, cli.addr)
-			}
 		}
 		switch cli.proto {
 		case "unix":

vendor/github.com/docker/docker/client/hijack.go

@@ -13,6 +13,11 @@ import (
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/versions"
 	"github.com/pkg/errors"
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/codes"
+	"go.opentelemetry.io/otel/propagation"
+	semconv "go.opentelemetry.io/otel/semconv/v1.7.0"
+	"go.opentelemetry.io/otel/trace"
 )
 
 // postHijacked sends a POST request and hijacks the connection.
@@ -45,11 +50,32 @@ func (cli *Client) DialHijack(ctx context.Context, url, proto string, meta map[s
 	return conn, err
 }
 
-func (cli *Client) setupHijackConn(req *http.Request, proto string) (net.Conn, string, error) {
+func (cli *Client) setupHijackConn(req *http.Request, proto string) (_ net.Conn, _ string, retErr error) {
 	ctx := req.Context()
 	req.Header.Set("Connection", "Upgrade")
 	req.Header.Set("Upgrade", proto)
 
+	// We aren't using the configured RoundTripper here so manually inject the trace context
+	tp := cli.tp
+	if tp == nil {
+		if span := trace.SpanFromContext(ctx); span.SpanContext().IsValid() {
+			tp = span.TracerProvider()
+		} else {
+			tp = otel.GetTracerProvider()
+		}
+	}
+
+	ctx, span := tp.Tracer("").Start(ctx, req.Method+" "+req.URL.Path)
+	span.SetAttributes(semconv.HTTPClientAttributesFromHTTPRequest(req)...)
+	defer func() {
+		if retErr != nil {
+			span.RecordError(retErr)
+			span.SetStatus(codes.Error, retErr.Error())
+		}
+		span.End()
+	}()
+	otel.GetTextMapPropagator().Inject(ctx, propagation.HeaderCarrier(req.Header))
+
 	dialer := cli.Dialer()
 	conn, err := dialer(ctx)
 	if err != nil {
@@ -71,6 +97,9 @@ func (cli *Client) setupHijackConn(req *http.Request, proto string) (net.Conn, s
 
 	// Server hijacks the connection, error 'connection closed' expected
 	resp, err := clientconn.Do(req)
+	if resp != nil {
+		span.SetStatus(semconv.SpanStatusFromHTTPStatusCode(resp.StatusCode))
+	}
 
 	//nolint:staticcheck // ignore SA1019 for connecting to old (pre go1.8) daemons
 	if err != httputil.ErrPersistEOF {

vendor/github.com/docker/docker/client/options.go

@@ -11,6 +11,7 @@ import (
 	"github.com/docker/go-connections/sockets"
 	"github.com/docker/go-connections/tlsconfig"
 	"github.com/pkg/errors"
+	"go.opentelemetry.io/otel/trace"
 )
 
 // Opt is a configuration option to initialize a [Client].
@@ -221,3 +222,12 @@ func WithAPIVersionNegotiation() Opt {
 		return nil
 	}
 }
+
+// WithTraceProvider sets the trace provider for the client.
+// If this is not set then the global trace provider will be used.
+func WithTraceProvider(provider trace.TracerProvider) Opt {
+	return func(c *Client) error {
+		c.tp = provider
+		return nil
+	}
+}

vendor/github.com/docker/docker/pkg/idtools/idtools_unix.go

@@ -10,17 +10,11 @@ import (
 	"os/exec"
 	"path/filepath"
 	"strconv"
-	"sync"
 	"syscall"
 
 	"github.com/opencontainers/runc/libcontainer/user"
 )
 
-var (
-	entOnce   sync.Once
-	getentCmd string
-)
-
 func mkdirAs(path string, mode os.FileMode, owner Identity, mkAll, chownExisting bool) error {
 	path, err := filepath.Abs(path)
 	if err != nil {
@@ -161,10 +155,10 @@ func getentGroup(name string) (user.Group, error) {
 }
 
 func callGetent(database, key string) (io.Reader, error) {
-	entOnce.Do(func() { getentCmd, _ = resolveBinary("getent") })
+	getentCmd, err := resolveBinary("getent")
-	// if no `getent` command on host, can't do anything else
+	// if no `getent` command within the execution environment, can't do anything else
-	if getentCmd == "" {
+	if err != nil {
-		return nil, fmt.Errorf("unable to find getent command")
+		return nil, fmt.Errorf("unable to find getent command: %w", err)
 	}
 	command := exec.Command(getentCmd, database, key)
 	// we run getent within container filesystem, but without /dev so /dev/null is not available for exec to mock stdin

vendor/github.com/docker/docker/pkg/system/errors.go

@@ -1,13 +1,6 @@
 package system // import "github.com/docker/docker/pkg/system"
 
-import (
+import "errors"
-	"errors"
-)
 
-var (
 // ErrNotSupportedPlatform means the platform is not supported.
-	ErrNotSupportedPlatform = errors.New("platform and architecture is not supported")
+var ErrNotSupportedPlatform = errors.New("platform and architecture is not supported")
-
-	// ErrNotSupportedOperatingSystem means the operating system is not supported.
-	ErrNotSupportedOperatingSystem = errors.New("operating system is not supported")
-)

vendor/github.com/docker/docker/pkg/system/image_os.go

@@ -1,10 +0,0 @@
-package system // import "github.com/docker/docker/pkg/system"
-import (
-	"runtime"
-	"strings"
-)
-
-// IsOSSupported determines if an operating system is supported by the host.
-func IsOSSupported(os string) bool {
-	return strings.EqualFold(runtime.GOOS, os)
-}

vendor/github.com/docker/docker/pkg/system/image_os_deprecated.go

@@ -0,0 +1,19 @@
+package system
+
+import (
+	"errors"
+	"runtime"
+	"strings"
+)
+
+// ErrNotSupportedOperatingSystem means the operating system is not supported.
+//
+// Deprecated: use [github.com/docker/docker/image.CheckOS] and check the error returned.
+var ErrNotSupportedOperatingSystem = errors.New("operating system is not supported")
+
+// IsOSSupported determines if an operating system is supported by the host.
+//
+// Deprecated: use [github.com/docker/docker/image.CheckOS] and check the error returned.
+func IsOSSupported(os string) bool {
+	return strings.EqualFold(runtime.GOOS, os)
+}

vendor/github.com/felixge/httpsnoop/.travis.yml

@@ -0,0 +1,6 @@
+language: go
+
+go:
+  - 1.6
+  - 1.7
+  - 1.8

vendor/github.com/felixge/httpsnoop/LICENSE.txt

@@ -0,0 +1,19 @@
+Copyright (c) 2016 Felix Geisendörfer (felix@debuggable.com)
+
+ Permission is hereby granted, free of charge, to any person obtaining a copy
+ of this software and associated documentation files (the "Software"), to deal
+ in the Software without restriction, including without limitation the rights
+ to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ copies of the Software, and to permit persons to whom the Software is
+ furnished to do so, subject to the following conditions:
+
+ The above copyright notice and this permission notice shall be included in
+ all copies or substantial portions of the Software.
+
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ THE SOFTWARE.

vendor/github.com/felixge/httpsnoop/Makefile

@@ -0,0 +1,10 @@
+.PHONY: ci generate clean
+
+ci: clean generate
+	go test -v ./...
+
+generate:
+	go generate .
+
+clean:
+	rm -rf *_generated*.go

vendor/github.com/felixge/httpsnoop/README.md

@@ -0,0 +1,95 @@
+# httpsnoop
+
+Package httpsnoop provides an easy way to capture http related metrics (i.e.
+response time, bytes written, and http status code) from your application's
+http.Handlers.
+
+Doing this requires non-trivial wrapping of the http.ResponseWriter interface,
+which is also exposed for users interested in a more low-level API.
+
+[![GoDoc](https://godoc.org/github.com/felixge/httpsnoop?status.svg)](https://godoc.org/github.com/felixge/httpsnoop)
+[![Build Status](https://travis-ci.org/felixge/httpsnoop.svg?branch=master)](https://travis-ci.org/felixge/httpsnoop)
+
+## Usage Example
+
+```go
+// myH is your app's http handler, perhaps a http.ServeMux or similar.
+var myH http.Handler
+// wrappedH wraps myH in order to log every request.
+wrappedH := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+	m := httpsnoop.CaptureMetrics(myH, w, r)
+	log.Printf(
+		"%s %s (code=%d dt=%s written=%d)",
+		r.Method,
+		r.URL,
+		m.Code,
+		m.Duration,
+		m.Written,
+	)
+})
+http.ListenAndServe(":8080", wrappedH)
+```
+
+## Why this package exists
+
+Instrumenting an application's http.Handler is surprisingly difficult.
+
+However if you google for e.g. "capture ResponseWriter status code" you'll find
+lots of advise and code examples that suggest it to be a fairly trivial
+undertaking. Unfortunately everything I've seen so far has a high chance of
+breaking your application.
+
+The main problem is that a `http.ResponseWriter` often implements additional
+interfaces such as `http.Flusher`, `http.CloseNotifier`, `http.Hijacker`, `http.Pusher`, and
+`io.ReaderFrom`. So the naive approach of just wrapping `http.ResponseWriter`
+in your own struct that also implements the `http.ResponseWriter` interface
+will hide the additional interfaces mentioned above. This has a high change of
+introducing subtle bugs into any non-trivial application.
+
+Another approach I've seen people take is to return a struct that implements
+all of the interfaces above. However, that's also problematic, because it's
+difficult to fake some of these interfaces behaviors when the underlying
+`http.ResponseWriter` doesn't have an implementation. It's also dangerous,
+because an application may choose to operate differently, merely because it
+detects the presence of these additional interfaces.
+
+This package solves this problem by checking which additional interfaces a
+`http.ResponseWriter` implements, returning a wrapped version implementing the
+exact same set of interfaces.
+
+Additionally this package properly handles edge cases such as `WriteHeader` not
+being called, or called more than once, as well as concurrent calls to
+`http.ResponseWriter` methods, and even calls happening after the wrapped
+`ServeHTTP` has already returned.
+
+Unfortunately this package is not perfect either. It's possible that it is
+still missing some interfaces provided by the go core (let me know if you find
+one), and it won't work for applications adding their own interfaces into the
+mix. You can however use `httpsnoop.Unwrap(w)` to access the underlying
+`http.ResponseWriter` and type-assert the result to its other interfaces.
+
+However, hopefully the explanation above has sufficiently scared you of rolling
+your own solution to this problem. httpsnoop may still break your application,
+but at least it tries to avoid it as much as possible.
+
+Anyway, the real problem here is that smuggling additional interfaces inside
+`http.ResponseWriter` is a problematic design choice, but it probably goes as
+deep as the Go language specification itself. But that's okay, I still prefer
+Go over the alternatives ;).
+
+## Performance
+
+```
+BenchmarkBaseline-8      	   20000	     94912 ns/op
+BenchmarkCaptureMetrics-8	   20000	     95461 ns/op
+```
+
+As you can see, using `CaptureMetrics` on a vanilla http.Handler introduces an
+overhead of ~500 ns per http request on my machine. However, the margin of
+error appears to be larger than that, therefor it should be reasonable to
+assume that the overhead introduced by `CaptureMetrics` is absolutely
+negligible.
+
+## License
+
+MIT

vendor/github.com/felixge/httpsnoop/capture_metrics.go

@@ -0,0 +1,86 @@
+package httpsnoop
+
+import (
+	"io"
+	"net/http"
+	"time"
+)
+
+// Metrics holds metrics captured from CaptureMetrics.
+type Metrics struct {
+	// Code is the first http response code passed to the WriteHeader func of
+	// the ResponseWriter. If no such call is made, a default code of 200 is
+	// assumed instead.
+	Code int
+	// Duration is the time it took to execute the handler.
+	Duration time.Duration
+	// Written is the number of bytes successfully written by the Write or
+	// ReadFrom function of the ResponseWriter. ResponseWriters may also write
+	// data to their underlaying connection directly (e.g. headers), but those
+	// are not tracked. Therefor the number of Written bytes will usually match
+	// the size of the response body.
+	Written int64
+}
+
+// CaptureMetrics wraps the given hnd, executes it with the given w and r, and
+// returns the metrics it captured from it.
+func CaptureMetrics(hnd http.Handler, w http.ResponseWriter, r *http.Request) Metrics {
+	return CaptureMetricsFn(w, func(ww http.ResponseWriter) {
+		hnd.ServeHTTP(ww, r)
+	})
+}
+
+// CaptureMetricsFn wraps w and calls fn with the wrapped w and returns the
+// resulting metrics. This is very similar to CaptureMetrics (which is just
+// sugar on top of this func), but is a more usable interface if your
+// application doesn't use the Go http.Handler interface.
+func CaptureMetricsFn(w http.ResponseWriter, fn func(http.ResponseWriter)) Metrics {
+	m := Metrics{Code: http.StatusOK}
+	m.CaptureMetrics(w, fn)
+	return m
+}
+
+// CaptureMetrics wraps w and calls fn with the wrapped w and updates
+// Metrics m with the resulting metrics. This is similar to CaptureMetricsFn,
+// but allows one to customize starting Metrics object.
+func (m *Metrics) CaptureMetrics(w http.ResponseWriter, fn func(http.ResponseWriter)) {
+	var (
+		start         = time.Now()
+		headerWritten bool
+		hooks         = Hooks{
+			WriteHeader: func(next WriteHeaderFunc) WriteHeaderFunc {
+				return func(code int) {
+					next(code)
+
+					if !headerWritten {
+						m.Code = code
+						headerWritten = true
+					}
+				}
+			},
+
+			Write: func(next WriteFunc) WriteFunc {
+				return func(p []byte) (int, error) {
+					n, err := next(p)
+
+					m.Written += int64(n)
+					headerWritten = true
+					return n, err
+				}
+			},
+
+			ReadFrom: func(next ReadFromFunc) ReadFromFunc {
+				return func(src io.Reader) (int64, error) {
+					n, err := next(src)
+
+					headerWritten = true
+					m.Written += n
+					return n, err
+				}
+			},
+		}
+	)
+
+	fn(Wrap(w, hooks))
+	m.Duration += time.Since(start)
+}

vendor/github.com/felixge/httpsnoop/docs.go

@@ -0,0 +1,10 @@
+// Package httpsnoop provides an easy way to capture http related metrics (i.e.
+// response time, bytes written, and http status code) from your application's
+// http.Handlers.
+//
+// Doing this requires non-trivial wrapping of the http.ResponseWriter
+// interface, which is also exposed for users interested in a more low-level
+// API.
+package httpsnoop
+
+//go:generate go run codegen/main.go

vendor/github.com/felixge/httpsnoop/wrap_generated_gteq_1.8.go

@@ -0,0 +1,436 @@
+// +build go1.8
+// Code generated by "httpsnoop/codegen"; DO NOT EDIT
+
+package httpsnoop
+
+import (
+	"bufio"
+	"io"
+	"net"
+	"net/http"
+)
+
+// HeaderFunc is part of the http.ResponseWriter interface.
+type HeaderFunc func() http.Header
+
+// WriteHeaderFunc is part of the http.ResponseWriter interface.
+type WriteHeaderFunc func(code int)
+
+// WriteFunc is part of the http.ResponseWriter interface.
+type WriteFunc func(b []byte) (int, error)
+
+// FlushFunc is part of the http.Flusher interface.
+type FlushFunc func()
+
+// CloseNotifyFunc is part of the http.CloseNotifier interface.
+type CloseNotifyFunc func() <-chan bool
+
+// HijackFunc is part of the http.Hijacker interface.
+type HijackFunc func() (net.Conn, *bufio.ReadWriter, error)
+
+// ReadFromFunc is part of the io.ReaderFrom interface.
+type ReadFromFunc func(src io.Reader) (int64, error)
+
+// PushFunc is part of the http.Pusher interface.
+type PushFunc func(target string, opts *http.PushOptions) error
+
+// Hooks defines a set of method interceptors for methods included in
+// http.ResponseWriter as well as some others. You can think of them as
+// middleware for the function calls they target. See Wrap for more details.
+type Hooks struct {
+	Header      func(HeaderFunc) HeaderFunc
+	WriteHeader func(WriteHeaderFunc) WriteHeaderFunc
+	Write       func(WriteFunc) WriteFunc
+	Flush       func(FlushFunc) FlushFunc
+	CloseNotify func(CloseNotifyFunc) CloseNotifyFunc
+	Hijack      func(HijackFunc) HijackFunc
+	ReadFrom    func(ReadFromFunc) ReadFromFunc
+	Push        func(PushFunc) PushFunc
+}
+
+// Wrap returns a wrapped version of w that provides the exact same interface
+// as w. Specifically if w implements any combination of:
+//
+// - http.Flusher
+// - http.CloseNotifier
+// - http.Hijacker
+// - io.ReaderFrom
+// - http.Pusher
+//
+// The wrapped version will implement the exact same combination. If no hooks
+// are set, the wrapped version also behaves exactly as w. Hooks targeting
+// methods not supported by w are ignored. Any other hooks will intercept the
+// method they target and may modify the call's arguments and/or return values.
+// The CaptureMetrics implementation serves as a working example for how the
+// hooks can be used.
+func Wrap(w http.ResponseWriter, hooks Hooks) http.ResponseWriter {
+	rw := &rw{w: w, h: hooks}
+	_, i0 := w.(http.Flusher)
+	_, i1 := w.(http.CloseNotifier)
+	_, i2 := w.(http.Hijacker)
+	_, i3 := w.(io.ReaderFrom)
+	_, i4 := w.(http.Pusher)
+	switch {
+	// combination 1/32
+	case !i0 && !i1 && !i2 && !i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+		}{rw, rw}
+	// combination 2/32
+	case !i0 && !i1 && !i2 && !i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Pusher
+		}{rw, rw, rw}
+	// combination 3/32
+	case !i0 && !i1 && !i2 && i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			io.ReaderFrom
+		}{rw, rw, rw}
+	// combination 4/32
+	case !i0 && !i1 && !i2 && i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			io.ReaderFrom
+			http.Pusher
+		}{rw, rw, rw, rw}
+	// combination 5/32
+	case !i0 && !i1 && i2 && !i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Hijacker
+		}{rw, rw, rw}
+	// combination 6/32
+	case !i0 && !i1 && i2 && !i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Hijacker
+			http.Pusher
+		}{rw, rw, rw, rw}
+	// combination 7/32
+	case !i0 && !i1 && i2 && i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Hijacker
+			io.ReaderFrom
+		}{rw, rw, rw, rw}
+	// combination 8/32
+	case !i0 && !i1 && i2 && i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Hijacker
+			io.ReaderFrom
+			http.Pusher
+		}{rw, rw, rw, rw, rw}
+	// combination 9/32
+	case !i0 && i1 && !i2 && !i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.CloseNotifier
+		}{rw, rw, rw}
+	// combination 10/32
+	case !i0 && i1 && !i2 && !i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.CloseNotifier
+			http.Pusher
+		}{rw, rw, rw, rw}
+	// combination 11/32
+	case !i0 && i1 && !i2 && i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.CloseNotifier
+			io.ReaderFrom
+		}{rw, rw, rw, rw}
+	// combination 12/32
+	case !i0 && i1 && !i2 && i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.CloseNotifier
+			io.ReaderFrom
+			http.Pusher
+		}{rw, rw, rw, rw, rw}
+	// combination 13/32
+	case !i0 && i1 && i2 && !i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.CloseNotifier
+			http.Hijacker
+		}{rw, rw, rw, rw}
+	// combination 14/32
+	case !i0 && i1 && i2 && !i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.CloseNotifier
+			http.Hijacker
+			http.Pusher
+		}{rw, rw, rw, rw, rw}
+	// combination 15/32
+	case !i0 && i1 && i2 && i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.CloseNotifier
+			http.Hijacker
+			io.ReaderFrom
+		}{rw, rw, rw, rw, rw}
+	// combination 16/32
+	case !i0 && i1 && i2 && i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.CloseNotifier
+			http.Hijacker
+			io.ReaderFrom
+			http.Pusher
+		}{rw, rw, rw, rw, rw, rw}
+	// combination 17/32
+	case i0 && !i1 && !i2 && !i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+		}{rw, rw, rw}
+	// combination 18/32
+	case i0 && !i1 && !i2 && !i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.Pusher
+		}{rw, rw, rw, rw}
+	// combination 19/32
+	case i0 && !i1 && !i2 && i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			io.ReaderFrom
+		}{rw, rw, rw, rw}
+	// combination 20/32
+	case i0 && !i1 && !i2 && i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			io.ReaderFrom
+			http.Pusher
+		}{rw, rw, rw, rw, rw}
+	// combination 21/32
+	case i0 && !i1 && i2 && !i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.Hijacker
+		}{rw, rw, rw, rw}
+	// combination 22/32
+	case i0 && !i1 && i2 && !i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.Hijacker
+			http.Pusher
+		}{rw, rw, rw, rw, rw}
+	// combination 23/32
+	case i0 && !i1 && i2 && i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.Hijacker
+			io.ReaderFrom
+		}{rw, rw, rw, rw, rw}
+	// combination 24/32
+	case i0 && !i1 && i2 && i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.Hijacker
+			io.ReaderFrom
+			http.Pusher
+		}{rw, rw, rw, rw, rw, rw}
+	// combination 25/32
+	case i0 && i1 && !i2 && !i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.CloseNotifier
+		}{rw, rw, rw, rw}
+	// combination 26/32
+	case i0 && i1 && !i2 && !i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.CloseNotifier
+			http.Pusher
+		}{rw, rw, rw, rw, rw}
+	// combination 27/32
+	case i0 && i1 && !i2 && i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.CloseNotifier
+			io.ReaderFrom
+		}{rw, rw, rw, rw, rw}
+	// combination 28/32
+	case i0 && i1 && !i2 && i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.CloseNotifier
+			io.ReaderFrom
+			http.Pusher
+		}{rw, rw, rw, rw, rw, rw}
+	// combination 29/32
+	case i0 && i1 && i2 && !i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.CloseNotifier
+			http.Hijacker
+		}{rw, rw, rw, rw, rw}
+	// combination 30/32
+	case i0 && i1 && i2 && !i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.CloseNotifier
+			http.Hijacker
+			http.Pusher
+		}{rw, rw, rw, rw, rw, rw}
+	// combination 31/32
+	case i0 && i1 && i2 && i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.CloseNotifier
+			http.Hijacker
+			io.ReaderFrom
+		}{rw, rw, rw, rw, rw, rw}
+	// combination 32/32
+	case i0 && i1 && i2 && i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.CloseNotifier
+			http.Hijacker
+			io.ReaderFrom
+			http.Pusher
+		}{rw, rw, rw, rw, rw, rw, rw}
+	}
+	panic("unreachable")
+}
+
+type rw struct {
+	w http.ResponseWriter
+	h Hooks
+}
+
+func (w *rw) Unwrap() http.ResponseWriter {
+	return w.w
+}
+
+func (w *rw) Header() http.Header {
+	f := w.w.(http.ResponseWriter).Header
+	if w.h.Header != nil {
+		f = w.h.Header(f)
+	}
+	return f()
+}
+
+func (w *rw) WriteHeader(code int) {
+	f := w.w.(http.ResponseWriter).WriteHeader
+	if w.h.WriteHeader != nil {
+		f = w.h.WriteHeader(f)
+	}
+	f(code)
+}
+
+func (w *rw) Write(b []byte) (int, error) {
+	f := w.w.(http.ResponseWriter).Write
+	if w.h.Write != nil {
+		f = w.h.Write(f)
+	}
+	return f(b)
+}
+
+func (w *rw) Flush() {
+	f := w.w.(http.Flusher).Flush
+	if w.h.Flush != nil {
+		f = w.h.Flush(f)
+	}
+	f()
+}
+
+func (w *rw) CloseNotify() <-chan bool {
+	f := w.w.(http.CloseNotifier).CloseNotify
+	if w.h.CloseNotify != nil {
+		f = w.h.CloseNotify(f)
+	}
+	return f()
+}
+
+func (w *rw) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	f := w.w.(http.Hijacker).Hijack
+	if w.h.Hijack != nil {
+		f = w.h.Hijack(f)
+	}
+	return f()
+}
+
+func (w *rw) ReadFrom(src io.Reader) (int64, error) {
+	f := w.w.(io.ReaderFrom).ReadFrom
+	if w.h.ReadFrom != nil {
+		f = w.h.ReadFrom(f)
+	}
+	return f(src)
+}
+
+func (w *rw) Push(target string, opts *http.PushOptions) error {
+	f := w.w.(http.Pusher).Push
+	if w.h.Push != nil {
+		f = w.h.Push(f)
+	}
+	return f(target, opts)
+}
+
+type Unwrapper interface {
+	Unwrap() http.ResponseWriter
+}
+
+// Unwrap returns the underlying http.ResponseWriter from within zero or more
+// layers of httpsnoop wrappers.
+func Unwrap(w http.ResponseWriter) http.ResponseWriter {
+	if rw, ok := w.(Unwrapper); ok {
+		// recurse until rw.Unwrap() returns a non-Unwrapper
+		return Unwrap(rw.Unwrap())
+	} else {
+		return w
+	}
+}

vendor/github.com/felixge/httpsnoop/wrap_generated_lt_1.8.go

@@ -0,0 +1,278 @@
+// +build !go1.8
+// Code generated by "httpsnoop/codegen"; DO NOT EDIT
+
+package httpsnoop
+
+import (
+	"bufio"
+	"io"
+	"net"
+	"net/http"
+)
+
+// HeaderFunc is part of the http.ResponseWriter interface.
+type HeaderFunc func() http.Header
+
+// WriteHeaderFunc is part of the http.ResponseWriter interface.
+type WriteHeaderFunc func(code int)
+
+// WriteFunc is part of the http.ResponseWriter interface.
+type WriteFunc func(b []byte) (int, error)
+
+// FlushFunc is part of the http.Flusher interface.
+type FlushFunc func()
+
+// CloseNotifyFunc is part of the http.CloseNotifier interface.
+type CloseNotifyFunc func() <-chan bool
+
+// HijackFunc is part of the http.Hijacker interface.
+type HijackFunc func() (net.Conn, *bufio.ReadWriter, error)
+
+// ReadFromFunc is part of the io.ReaderFrom interface.
+type ReadFromFunc func(src io.Reader) (int64, error)
+
+// Hooks defines a set of method interceptors for methods included in
+// http.ResponseWriter as well as some others. You can think of them as
+// middleware for the function calls they target. See Wrap for more details.
+type Hooks struct {
+	Header      func(HeaderFunc) HeaderFunc
+	WriteHeader func(WriteHeaderFunc) WriteHeaderFunc
+	Write       func(WriteFunc) WriteFunc
+	Flush       func(FlushFunc) FlushFunc
+	CloseNotify func(CloseNotifyFunc) CloseNotifyFunc
+	Hijack      func(HijackFunc) HijackFunc
+	ReadFrom    func(ReadFromFunc) ReadFromFunc
+}
+
+// Wrap returns a wrapped version of w that provides the exact same interface
+// as w. Specifically if w implements any combination of:
+//
+// - http.Flusher
+// - http.CloseNotifier
+// - http.Hijacker
+// - io.ReaderFrom
+//
+// The wrapped version will implement the exact same combination. If no hooks
+// are set, the wrapped version also behaves exactly as w. Hooks targeting
+// methods not supported by w are ignored. Any other hooks will intercept the
+// method they target and may modify the call's arguments and/or return values.
+// The CaptureMetrics implementation serves as a working example for how the
+// hooks can be used.
+func Wrap(w http.ResponseWriter, hooks Hooks) http.ResponseWriter {
+	rw := &rw{w: w, h: hooks}
+	_, i0 := w.(http.Flusher)
+	_, i1 := w.(http.CloseNotifier)
+	_, i2 := w.(http.Hijacker)
+	_, i3 := w.(io.ReaderFrom)
+	switch {
+	// combination 1/16
+	case !i0 && !i1 && !i2 && !i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+		}{rw, rw}
+	// combination 2/16
+	case !i0 && !i1 && !i2 && i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			io.ReaderFrom
+		}{rw, rw, rw}
+	// combination 3/16
+	case !i0 && !i1 && i2 && !i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Hijacker
+		}{rw, rw, rw}
+	// combination 4/16
+	case !i0 && !i1 && i2 && i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Hijacker
+			io.ReaderFrom
+		}{rw, rw, rw, rw}
+	// combination 5/16
+	case !i0 && i1 && !i2 && !i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.CloseNotifier
+		}{rw, rw, rw}
+	// combination 6/16
+	case !i0 && i1 && !i2 && i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.CloseNotifier
+			io.ReaderFrom
+		}{rw, rw, rw, rw}
+	// combination 7/16
+	case !i0 && i1 && i2 && !i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.CloseNotifier
+			http.Hijacker
+		}{rw, rw, rw, rw}
+	// combination 8/16
+	case !i0 && i1 && i2 && i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.CloseNotifier
+			http.Hijacker
+			io.ReaderFrom
+		}{rw, rw, rw, rw, rw}
+	// combination 9/16
+	case i0 && !i1 && !i2 && !i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+		}{rw, rw, rw}
+	// combination 10/16
+	case i0 && !i1 && !i2 && i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			io.ReaderFrom
+		}{rw, rw, rw, rw}
+	// combination 11/16
+	case i0 && !i1 && i2 && !i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.Hijacker
+		}{rw, rw, rw, rw}
+	// combination 12/16
+	case i0 && !i1 && i2 && i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.Hijacker
+			io.ReaderFrom
+		}{rw, rw, rw, rw, rw}
+	// combination 13/16
+	case i0 && i1 && !i2 && !i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.CloseNotifier
+		}{rw, rw, rw, rw}
+	// combination 14/16
+	case i0 && i1 && !i2 && i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.CloseNotifier
+			io.ReaderFrom
+		}{rw, rw, rw, rw, rw}
+	// combination 15/16
+	case i0 && i1 && i2 && !i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.CloseNotifier
+			http.Hijacker
+		}{rw, rw, rw, rw, rw}
+	// combination 16/16
+	case i0 && i1 && i2 && i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.CloseNotifier
+			http.Hijacker
+			io.ReaderFrom
+		}{rw, rw, rw, rw, rw, rw}
+	}
+	panic("unreachable")
+}
+
+type rw struct {
+	w http.ResponseWriter
+	h Hooks
+}
+
+func (w *rw) Unwrap() http.ResponseWriter {
+	return w.w
+}
+
+func (w *rw) Header() http.Header {
+	f := w.w.(http.ResponseWriter).Header
+	if w.h.Header != nil {
+		f = w.h.Header(f)
+	}
+	return f()
+}
+
+func (w *rw) WriteHeader(code int) {
+	f := w.w.(http.ResponseWriter).WriteHeader
+	if w.h.WriteHeader != nil {
+		f = w.h.WriteHeader(f)
+	}
+	f(code)
+}
+
+func (w *rw) Write(b []byte) (int, error) {
+	f := w.w.(http.ResponseWriter).Write
+	if w.h.Write != nil {
+		f = w.h.Write(f)
+	}
+	return f(b)
+}
+
+func (w *rw) Flush() {
+	f := w.w.(http.Flusher).Flush
+	if w.h.Flush != nil {
+		f = w.h.Flush(f)
+	}
+	f()
+}
+
+func (w *rw) CloseNotify() <-chan bool {
+	f := w.w.(http.CloseNotifier).CloseNotify
+	if w.h.CloseNotify != nil {
+		f = w.h.CloseNotify(f)
+	}
+	return f()
+}
+
+func (w *rw) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	f := w.w.(http.Hijacker).Hijack
+	if w.h.Hijack != nil {
+		f = w.h.Hijack(f)
+	}
+	return f()
+}
+
+func (w *rw) ReadFrom(src io.Reader) (int64, error) {
+	f := w.w.(io.ReaderFrom).ReadFrom
+	if w.h.ReadFrom != nil {
+		f = w.h.ReadFrom(f)
+	}
+	return f(src)
+}
+
+type Unwrapper interface {
+	Unwrap() http.ResponseWriter
+}
+
+// Unwrap returns the underlying http.ResponseWriter from within zero or more
+// layers of httpsnoop wrappers.
+func Unwrap(w http.ResponseWriter) http.ResponseWriter {
+	if rw, ok := w.(Unwrapper); ok {
+		// recurse until rw.Unwrap() returns a non-Unwrapper
+		return Unwrap(rw.Unwrap())
+	} else {
+		return w
+	}
+}

vendor/github.com/go-logr/logr/.golangci.yaml

@@ -0,0 +1,29 @@
+run:
+  timeout: 1m
+  tests: true
+
+linters:
+  disable-all: true
+  enable:
+    - asciicheck
+    - deadcode
+    - errcheck
+    - forcetypeassert
+    - gocritic
+    - gofmt
+    - goimports
+    - gosimple
+    - govet
+    - ineffassign
+    - misspell
+    - revive
+    - staticcheck
+    - structcheck
+    - typecheck
+    - unused
+    - varcheck
+
+issues:
+  exclude-use-default: false
+  max-issues-per-linter: 0
+  max-same-issues: 10

vendor/github.com/go-logr/logr/CHANGELOG.md

@@ -0,0 +1,6 @@
+# CHANGELOG
+
+## v1.0.0-rc1
+
+This is the first logged release.  Major changes (including breaking changes)
+have occurred since earlier tags.

vendor/github.com/go-logr/logr/CONTRIBUTING.md

@@ -0,0 +1,17 @@
+# Contributing
+
+Logr is open to pull-requests, provided they fit within the intended scope of
+the project.  Specifically, this library aims to be VERY small and minimalist,
+with no external dependencies.
+
+## Compatibility
+
+This project intends to follow [semantic versioning](http://semver.org) and
+is very strict about compatibility.  Any proposed changes MUST follow those
+rules.
+
+## Performance
+
+As a logging library, logr must be as light-weight as possible.  Any proposed
+code change must include results of running the [benchmark](./benchmark)
+before and after the change.

vendor/github.com/go-logr/logr/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
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+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
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+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
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+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "{}"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
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+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
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+
+   Copyright {yyyy} {name of copyright owner}
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/github.com/go-logr/logr/README.md

@@ -0,0 +1,282 @@
+# A minimal logging API for Go
+
+[![Go Reference](https://pkg.go.dev/badge/github.com/go-logr/logr.svg)](https://pkg.go.dev/github.com/go-logr/logr)
+
+logr offers an(other) opinion on how Go programs and libraries can do logging
+without becoming coupled to a particular logging implementation.  This is not
+an implementation of logging - it is an API.  In fact it is two APIs with two
+different sets of users.
+
+The `Logger` type is intended for application and library authors.  It provides
+a relatively small API which can be used everywhere you want to emit logs.  It
+defers the actual act of writing logs (to files, to stdout, or whatever) to the
+`LogSink` interface.
+
+The `LogSink` interface is intended for logging library implementers.  It is a
+pure interface which can be implemented by logging frameworks to provide the actual logging
+functionality.
+
+This decoupling allows application and library developers to write code in
+terms of `logr.Logger` (which has very low dependency fan-out) while the
+implementation of logging is managed "up stack" (e.g. in or near `main()`.)
+Application developers can then switch out implementations as necessary.
+
+Many people assert that libraries should not be logging, and as such efforts
+like this are pointless.  Those people are welcome to convince the authors of
+the tens-of-thousands of libraries that *DO* write logs that they are all
+wrong.  In the meantime, logr takes a more practical approach.
+
+## Typical usage
+
+Somewhere, early in an application's life, it will make a decision about which
+logging library (implementation) it actually wants to use.  Something like:
+
+```
+    func main() {
+        // ... other setup code ...
+
+        // Create the "root" logger.  We have chosen the "logimpl" implementation,
+        // which takes some initial parameters and returns a logr.Logger.
+        logger := logimpl.New(param1, param2)
+
+        // ... other setup code ...
+```
+
+Most apps will call into other libraries, create structures to govern the flow,
+etc.  The `logr.Logger` object can be passed to these other libraries, stored
+in structs, or even used as a package-global variable, if needed.  For example:
+
+```
+    app := createTheAppObject(logger)
+    app.Run()
+```
+
+Outside of this early setup, no other packages need to know about the choice of
+implementation.  They write logs in terms of the `logr.Logger` that they
+received:
+
+```
+    type appObject struct {
+        // ... other fields ...
+        logger logr.Logger
+        // ... other fields ...
+    }
+
+    func (app *appObject) Run() {
+        app.logger.Info("starting up", "timestamp", time.Now())
+
+        // ... app code ...
+```
+
+## Background
+
+If the Go standard library had defined an interface for logging, this project
+probably would not be needed.  Alas, here we are.
+
+### Inspiration
+
+Before you consider this package, please read [this blog post by the
+inimitable Dave Cheney][warning-makes-no-sense].  We really appreciate what
+he has to say, and it largely aligns with our own experiences.
+
+### Differences from Dave's ideas
+
+The main differences are:
+
+1. Dave basically proposes doing away with the notion of a logging API in favor
+of `fmt.Printf()`.  We disagree, especially when you consider things like output
+locations, timestamps, file and line decorations, and structured logging.  This
+package restricts the logging API to just 2 types of logs: info and error.
+
+Info logs are things you want to tell the user which are not errors.  Error
+logs are, well, errors.  If your code receives an `error` from a subordinate
+function call and is logging that `error` *and not returning it*, use error
+logs.
+
+2. Verbosity-levels on info logs.  This gives developers a chance to indicate
+arbitrary grades of importance for info logs, without assigning names with
+semantic meaning such as "warning", "trace", and "debug."  Superficially this
+may feel very similar, but the primary difference is the lack of semantics.
+Because verbosity is a numerical value, it's safe to assume that an app running
+with higher verbosity means more (and less important) logs will be generated.
+
+## Implementations (non-exhaustive)
+
+There are implementations for the following logging libraries:
+
+- **a function** (can bridge to non-structured libraries): [funcr](https://github.com/go-logr/logr/tree/master/funcr)
+- **a testing.T** (for use in Go tests, with JSON-like output): [testr](https://github.com/go-logr/logr/tree/master/testr)
+- **github.com/google/glog**: [glogr](https://github.com/go-logr/glogr)
+- **k8s.io/klog** (for Kubernetes): [klogr](https://git.k8s.io/klog/klogr)
+- **a testing.T** (with klog-like text output): [ktesting](https://git.k8s.io/klog/ktesting)
+- **go.uber.org/zap**: [zapr](https://github.com/go-logr/zapr)
+- **log** (the Go standard library logger): [stdr](https://github.com/go-logr/stdr)
+- **github.com/sirupsen/logrus**: [logrusr](https://github.com/bombsimon/logrusr)
+- **github.com/wojas/genericr**: [genericr](https://github.com/wojas/genericr) (makes it easy to implement your own backend)
+- **logfmt** (Heroku style [logging](https://www.brandur.org/logfmt)): [logfmtr](https://github.com/iand/logfmtr)
+- **github.com/rs/zerolog**: [zerologr](https://github.com/go-logr/zerologr)
+- **github.com/go-kit/log**: [gokitlogr](https://github.com/tonglil/gokitlogr) (also compatible with github.com/go-kit/kit/log since v0.12.0)
+- **bytes.Buffer** (writing to a buffer): [bufrlogr](https://github.com/tonglil/buflogr) (useful for ensuring values were logged, like during testing)
+
+## FAQ
+
+### Conceptual
+
+#### Why structured logging?
+
+- **Structured logs are more easily queryable**: Since you've got
+  key-value pairs, it's much easier to query your structured logs for
+  particular values by filtering on the contents of a particular key --
+  think searching request logs for error codes, Kubernetes reconcilers for
+  the name and namespace of the reconciled object, etc.
+
+- **Structured logging makes it easier to have cross-referenceable logs**:
+  Similarly to searchability, if you maintain conventions around your
+  keys, it becomes easy to gather all log lines related to a particular
+  concept.
+
+- **Structured logs allow better dimensions of filtering**: if you have
+  structure to your logs, you've got more precise control over how much
+  information is logged -- you might choose in a particular configuration
+  to log certain keys but not others, only log lines where a certain key
+  matches a certain value, etc., instead of just having v-levels and names
+  to key off of.
+
+- **Structured logs better represent structured data**: sometimes, the
+  data that you want to log is inherently structured (think tuple-link
+  objects.)  Structured logs allow you to preserve that structure when
+  outputting.
+
+#### Why V-levels?
+
+**V-levels give operators an easy way to control the chattiness of log
+operations**.  V-levels provide a way for a given package to distinguish
+the relative importance or verbosity of a given log message.  Then, if
+a particular logger or package is logging too many messages, the user
+of the package can simply change the v-levels for that library.
+
+#### Why not named levels, like Info/Warning/Error?
+
+Read [Dave Cheney's post][warning-makes-no-sense].  Then read [Differences
+from Dave's ideas](#differences-from-daves-ideas).
+
+#### Why not allow format strings, too?
+
+**Format strings negate many of the benefits of structured logs**:
+
+- They're not easily searchable without resorting to fuzzy searching,
+  regular expressions, etc.
+
+- They don't store structured data well, since contents are flattened into
+  a string.
+
+- They're not cross-referenceable.
+
+- They don't compress easily, since the message is not constant.
+
+(Unless you turn positional parameters into key-value pairs with numerical
+keys, at which point you've gotten key-value logging with meaningless
+keys.)
+
+### Practical
+
+#### Why key-value pairs, and not a map?
+
+Key-value pairs are *much* easier to optimize, especially around
+allocations.  Zap (a structured logger that inspired logr's interface) has
+[performance measurements](https://github.com/uber-go/zap#performance)
+that show this quite nicely.
+
+While the interface ends up being a little less obvious, you get
+potentially better performance, plus avoid making users type
+`map[string]string{}` every time they want to log.
+
+#### What if my V-levels differ between libraries?
+
+That's fine.  Control your V-levels on a per-logger basis, and use the
+`WithName` method to pass different loggers to different libraries.
+
+Generally, you should take care to ensure that you have relatively
+consistent V-levels within a given logger, however, as this makes deciding
+on what verbosity of logs to request easier.
+
+#### But I really want to use a format string!
+
+That's not actually a question.  Assuming your question is "how do
+I convert my mental model of logging with format strings to logging with
+constant messages":
+
+1. Figure out what the error actually is, as you'd write in a TL;DR style,
+   and use that as a message.
+
+2. For every place you'd write a format specifier, look to the word before
+   it, and add that as a key value pair.
+
+For instance, consider the following examples (all taken from spots in the
+Kubernetes codebase):
+
+- `klog.V(4).Infof("Client is returning errors: code %v, error %v",
+  responseCode, err)` becomes `logger.Error(err, "client returned an
+  error", "code", responseCode)`
+
+- `klog.V(4).Infof("Got a Retry-After %ds response for attempt %d to %v",
+  seconds, retries, url)` becomes `logger.V(4).Info("got a retry-after
+  response when requesting url", "attempt", retries, "after
+  seconds", seconds, "url", url)`
+
+If you *really* must use a format string, use it in a key's value, and
+call `fmt.Sprintf` yourself.  For instance: `log.Printf("unable to
+reflect over type %T")` becomes `logger.Info("unable to reflect over
+type", "type", fmt.Sprintf("%T"))`.  In general though, the cases where
+this is necessary should be few and far between.
+
+#### How do I choose my V-levels?
+
+This is basically the only hard constraint: increase V-levels to denote
+more verbose or more debug-y logs.
+
+Otherwise, you can start out with `0` as "you always want to see this",
+`1` as "common logging that you might *possibly* want to turn off", and
+`10` as "I would like to performance-test your log collection stack."
+
+Then gradually choose levels in between as you need them, working your way
+down from 10 (for debug and trace style logs) and up from 1 (for chattier
+info-type logs.)
+
+#### How do I choose my keys?
+
+Keys are fairly flexible, and can hold more or less any string
+value. For best compatibility with implementations and consistency
+with existing code in other projects, there are a few conventions you
+should consider.
+
+- Make your keys human-readable.
+- Constant keys are generally a good idea.
+- Be consistent across your codebase.
+- Keys should naturally match parts of the message string.
+- Use lower case for simple keys and
+  [lowerCamelCase](https://en.wiktionary.org/wiki/lowerCamelCase) for
+  more complex ones. Kubernetes is one example of a project that has
+  [adopted that
+  convention](https://github.com/kubernetes/community/blob/HEAD/contributors/devel/sig-instrumentation/migration-to-structured-logging.md#name-arguments).
+
+While key names are mostly unrestricted (and spaces are acceptable),
+it's generally a good idea to stick to printable ascii characters, or at
+least match the general character set of your log lines.
+
+#### Why should keys be constant values?
+
+The point of structured logging is to make later log processing easier.  Your
+keys are, effectively, the schema of each log message.  If you use different
+keys across instances of the same log line, you will make your structured logs
+much harder to use.  `Sprintf()` is for values, not for keys!
+
+#### Why is this not a pure interface?
+
+The Logger type is implemented as a struct in order to allow the Go compiler to
+optimize things like high-V `Info` logs that are not triggered.  Not all of
+these implementations are implemented yet, but this structure was suggested as
+a way to ensure they *can* be implemented.  All of the real work is behind the
+`LogSink` interface.
+
+[warning-makes-no-sense]: http://dave.cheney.net/2015/11/05/lets-talk-about-logging

vendor/github.com/go-logr/logr/discard.go

@@ -0,0 +1,54 @@
+/*
+Copyright 2020 The logr Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package logr
+
+// Discard returns a Logger that discards all messages logged to it.  It can be
+// used whenever the caller is not interested in the logs.  Logger instances
+// produced by this function always compare as equal.
+func Discard() Logger {
+	return Logger{
+		level: 0,
+		sink:  discardLogSink{},
+	}
+}
+
+// discardLogSink is a LogSink that discards all messages.
+type discardLogSink struct{}
+
+// Verify that it actually implements the interface
+var _ LogSink = discardLogSink{}
+
+func (l discardLogSink) Init(RuntimeInfo) {
+}
+
+func (l discardLogSink) Enabled(int) bool {
+	return false
+}
+
+func (l discardLogSink) Info(int, string, ...interface{}) {
+}
+
+func (l discardLogSink) Error(error, string, ...interface{}) {
+}
+
+func (l discardLogSink) WithValues(...interface{}) LogSink {
+	return l
+}
+
+func (l discardLogSink) WithName(string) LogSink {
+	return l
+}

vendor/github.com/go-logr/logr/funcr/funcr.go

@@ -0,0 +1,787 @@
+/*
+Copyright 2021 The logr Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Package funcr implements formatting of structured log messages and
+// optionally captures the call site and timestamp.
+//
+// The simplest way to use it is via its implementation of a
+// github.com/go-logr/logr.LogSink with output through an arbitrary
+// "write" function.  See New and NewJSON for details.
+//
+// Custom LogSinks
+//
+// For users who need more control, a funcr.Formatter can be embedded inside
+// your own custom LogSink implementation. This is useful when the LogSink
+// needs to implement additional methods, for example.
+//
+// Formatting
+//
+// This will respect logr.Marshaler, fmt.Stringer, and error interfaces for
+// values which are being logged.  When rendering a struct, funcr will use Go's
+// standard JSON tags (all except "string").
+package funcr
+
+import (
+	"bytes"
+	"encoding"
+	"fmt"
+	"path/filepath"
+	"reflect"
+	"runtime"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/go-logr/logr"
+)
+
+// New returns a logr.Logger which is implemented by an arbitrary function.
+func New(fn func(prefix, args string), opts Options) logr.Logger {
+	return logr.New(newSink(fn, NewFormatter(opts)))
+}
+
+// NewJSON returns a logr.Logger which is implemented by an arbitrary function
+// and produces JSON output.
+func NewJSON(fn func(obj string), opts Options) logr.Logger {
+	fnWrapper := func(_, obj string) {
+		fn(obj)
+	}
+	return logr.New(newSink(fnWrapper, NewFormatterJSON(opts)))
+}
+
+// Underlier exposes access to the underlying logging function. Since
+// callers only have a logr.Logger, they have to know which
+// implementation is in use, so this interface is less of an
+// abstraction and more of a way to test type conversion.
+type Underlier interface {
+	GetUnderlying() func(prefix, args string)
+}
+
+func newSink(fn func(prefix, args string), formatter Formatter) logr.LogSink {
+	l := &fnlogger{
+		Formatter: formatter,
+		write:     fn,
+	}
+	// For skipping fnlogger.Info and fnlogger.Error.
+	l.Formatter.AddCallDepth(1)
+	return l
+}
+
+// Options carries parameters which influence the way logs are generated.
+type Options struct {
+	// LogCaller tells funcr to add a "caller" key to some or all log lines.
+	// This has some overhead, so some users might not want it.
+	LogCaller MessageClass
+
+	// LogCallerFunc tells funcr to also log the calling function name.  This
+	// has no effect if caller logging is not enabled (see Options.LogCaller).
+	LogCallerFunc bool
+
+	// LogTimestamp tells funcr to add a "ts" key to log lines.  This has some
+	// overhead, so some users might not want it.
+	LogTimestamp bool
+
+	// TimestampFormat tells funcr how to render timestamps when LogTimestamp
+	// is enabled.  If not specified, a default format will be used.  For more
+	// details, see docs for Go's time.Layout.
+	TimestampFormat string
+
+	// Verbosity tells funcr which V logs to produce.  Higher values enable
+	// more logs.  Info logs at or below this level will be written, while logs
+	// above this level will be discarded.
+	Verbosity int
+
+	// RenderBuiltinsHook allows users to mutate the list of key-value pairs
+	// while a log line is being rendered.  The kvList argument follows logr
+	// conventions - each pair of slice elements is comprised of a string key
+	// and an arbitrary value (verified and sanitized before calling this
+	// hook).  The value returned must follow the same conventions.  This hook
+	// can be used to audit or modify logged data.  For example, you might want
+	// to prefix all of funcr's built-in keys with some string.  This hook is
+	// only called for built-in (provided by funcr itself) key-value pairs.
+	// Equivalent hooks are offered for key-value pairs saved via
+	// logr.Logger.WithValues or Formatter.AddValues (see RenderValuesHook) and
+	// for user-provided pairs (see RenderArgsHook).
+	RenderBuiltinsHook func(kvList []interface{}) []interface{}
+
+	// RenderValuesHook is the same as RenderBuiltinsHook, except that it is
+	// only called for key-value pairs saved via logr.Logger.WithValues.  See
+	// RenderBuiltinsHook for more details.
+	RenderValuesHook func(kvList []interface{}) []interface{}
+
+	// RenderArgsHook is the same as RenderBuiltinsHook, except that it is only
+	// called for key-value pairs passed directly to Info and Error.  See
+	// RenderBuiltinsHook for more details.
+	RenderArgsHook func(kvList []interface{}) []interface{}
+
+	// MaxLogDepth tells funcr how many levels of nested fields (e.g. a struct
+	// that contains a struct, etc.) it may log.  Every time it finds a struct,
+	// slice, array, or map the depth is increased by one.  When the maximum is
+	// reached, the value will be converted to a string indicating that the max
+	// depth has been exceeded.  If this field is not specified, a default
+	// value will be used.
+	MaxLogDepth int
+}
+
+// MessageClass indicates which category or categories of messages to consider.
+type MessageClass int
+
+const (
+	// None ignores all message classes.
+	None MessageClass = iota
+	// All considers all message classes.
+	All
+	// Info only considers info messages.
+	Info
+	// Error only considers error messages.
+	Error
+)
+
+// fnlogger inherits some of its LogSink implementation from Formatter
+// and just needs to add some glue code.
+type fnlogger struct {
+	Formatter
+	write func(prefix, args string)
+}
+
+func (l fnlogger) WithName(name string) logr.LogSink {
+	l.Formatter.AddName(name)
+	return &l
+}
+
+func (l fnlogger) WithValues(kvList ...interface{}) logr.LogSink {
+	l.Formatter.AddValues(kvList)
+	return &l
+}
+
+func (l fnlogger) WithCallDepth(depth int) logr.LogSink {
+	l.Formatter.AddCallDepth(depth)
+	return &l
+}
+
+func (l fnlogger) Info(level int, msg string, kvList ...interface{}) {
+	prefix, args := l.FormatInfo(level, msg, kvList)
+	l.write(prefix, args)
+}
+
+func (l fnlogger) Error(err error, msg string, kvList ...interface{}) {
+	prefix, args := l.FormatError(err, msg, kvList)
+	l.write(prefix, args)
+}
+
+func (l fnlogger) GetUnderlying() func(prefix, args string) {
+	return l.write
+}
+
+// Assert conformance to the interfaces.
+var _ logr.LogSink = &fnlogger{}
+var _ logr.CallDepthLogSink = &fnlogger{}
+var _ Underlier = &fnlogger{}
+
+// NewFormatter constructs a Formatter which emits a JSON-like key=value format.
+func NewFormatter(opts Options) Formatter {
+	return newFormatter(opts, outputKeyValue)
+}
+
+// NewFormatterJSON constructs a Formatter which emits strict JSON.
+func NewFormatterJSON(opts Options) Formatter {
+	return newFormatter(opts, outputJSON)
+}
+
+// Defaults for Options.
+const defaultTimestampFormat = "2006-01-02 15:04:05.000000"
+const defaultMaxLogDepth = 16
+
+func newFormatter(opts Options, outfmt outputFormat) Formatter {
+	if opts.TimestampFormat == "" {
+		opts.TimestampFormat = defaultTimestampFormat
+	}
+	if opts.MaxLogDepth == 0 {
+		opts.MaxLogDepth = defaultMaxLogDepth
+	}
+	f := Formatter{
+		outputFormat: outfmt,
+		prefix:       "",
+		values:       nil,
+		depth:        0,
+		opts:         opts,
+	}
+	return f
+}
+
+// Formatter is an opaque struct which can be embedded in a LogSink
+// implementation. It should be constructed with NewFormatter. Some of
+// its methods directly implement logr.LogSink.
+type Formatter struct {
+	outputFormat outputFormat
+	prefix       string
+	values       []interface{}
+	valuesStr    string
+	depth        int
+	opts         Options
+}
+
+// outputFormat indicates which outputFormat to use.
+type outputFormat int
+
+const (
+	// outputKeyValue emits a JSON-like key=value format, but not strict JSON.
+	outputKeyValue outputFormat = iota
+	// outputJSON emits strict JSON.
+	outputJSON
+)
+
+// PseudoStruct is a list of key-value pairs that gets logged as a struct.
+type PseudoStruct []interface{}
+
+// render produces a log line, ready to use.
+func (f Formatter) render(builtins, args []interface{}) string {
+	// Empirically bytes.Buffer is faster than strings.Builder for this.
+	buf := bytes.NewBuffer(make([]byte, 0, 1024))
+	if f.outputFormat == outputJSON {
+		buf.WriteByte('{')
+	}
+	vals := builtins
+	if hook := f.opts.RenderBuiltinsHook; hook != nil {
+		vals = hook(f.sanitize(vals))
+	}
+	f.flatten(buf, vals, false, false) // keys are ours, no need to escape
+	continuing := len(builtins) > 0
+	if len(f.valuesStr) > 0 {
+		if continuing {
+			if f.outputFormat == outputJSON {
+				buf.WriteByte(',')
+			} else {
+				buf.WriteByte(' ')
+			}
+		}
+		continuing = true
+		buf.WriteString(f.valuesStr)
+	}
+	vals = args
+	if hook := f.opts.RenderArgsHook; hook != nil {
+		vals = hook(f.sanitize(vals))
+	}
+	f.flatten(buf, vals, continuing, true) // escape user-provided keys
+	if f.outputFormat == outputJSON {
+		buf.WriteByte('}')
+	}
+	return buf.String()
+}
+
+// flatten renders a list of key-value pairs into a buffer.  If continuing is
+// true, it assumes that the buffer has previous values and will emit a
+// separator (which depends on the output format) before the first pair it
+// writes.  If escapeKeys is true, the keys are assumed to have
+// non-JSON-compatible characters in them and must be evaluated for escapes.
+//
+// This function returns a potentially modified version of kvList, which
+// ensures that there is a value for every key (adding a value if needed) and
+// that each key is a string (substituting a key if needed).
+func (f Formatter) flatten(buf *bytes.Buffer, kvList []interface{}, continuing bool, escapeKeys bool) []interface{} {
+	// This logic overlaps with sanitize() but saves one type-cast per key,
+	// which can be measurable.
+	if len(kvList)%2 != 0 {
+		kvList = append(kvList, noValue)
+	}
+	for i := 0; i < len(kvList); i += 2 {
+		k, ok := kvList[i].(string)
+		if !ok {
+			k = f.nonStringKey(kvList[i])
+			kvList[i] = k
+		}
+		v := kvList[i+1]
+
+		if i > 0 || continuing {
+			if f.outputFormat == outputJSON {
+				buf.WriteByte(',')
+			} else {
+				// In theory the format could be something we don't understand.  In
+				// practice, we control it, so it won't be.
+				buf.WriteByte(' ')
+			}
+		}
+
+		if escapeKeys {
+			buf.WriteString(prettyString(k))
+		} else {
+			// this is faster
+			buf.WriteByte('"')
+			buf.WriteString(k)
+			buf.WriteByte('"')
+		}
+		if f.outputFormat == outputJSON {
+			buf.WriteByte(':')
+		} else {
+			buf.WriteByte('=')
+		}
+		buf.WriteString(f.pretty(v))
+	}
+	return kvList
+}
+
+func (f Formatter) pretty(value interface{}) string {
+	return f.prettyWithFlags(value, 0, 0)
+}
+
+const (
+	flagRawStruct = 0x1 // do not print braces on structs
+)
+
+// TODO: This is not fast. Most of the overhead goes here.
+func (f Formatter) prettyWithFlags(value interface{}, flags uint32, depth int) string {
+	if depth > f.opts.MaxLogDepth {
+		return `"<max-log-depth-exceeded>"`
+	}
+
+	// Handle types that take full control of logging.
+	if v, ok := value.(logr.Marshaler); ok {
+		// Replace the value with what the type wants to get logged.
+		// That then gets handled below via reflection.
+		value = invokeMarshaler(v)
+	}
+
+	// Handle types that want to format themselves.
+	switch v := value.(type) {
+	case fmt.Stringer:
+		value = invokeStringer(v)
+	case error:
+		value = invokeError(v)
+	}
+
+	// Handling the most common types without reflect is a small perf win.
+	switch v := value.(type) {
+	case bool:
+		return strconv.FormatBool(v)
+	case string:
+		return prettyString(v)
+	case int:
+		return strconv.FormatInt(int64(v), 10)
+	case int8:
+		return strconv.FormatInt(int64(v), 10)
+	case int16:
+		return strconv.FormatInt(int64(v), 10)
+	case int32:
+		return strconv.FormatInt(int64(v), 10)
+	case int64:
+		return strconv.FormatInt(int64(v), 10)
+	case uint:
+		return strconv.FormatUint(uint64(v), 10)
+	case uint8:
+		return strconv.FormatUint(uint64(v), 10)
+	case uint16:
+		return strconv.FormatUint(uint64(v), 10)
+	case uint32:
+		return strconv.FormatUint(uint64(v), 10)
+	case uint64:
+		return strconv.FormatUint(v, 10)
+	case uintptr:
+		return strconv.FormatUint(uint64(v), 10)
+	case float32:
+		return strconv.FormatFloat(float64(v), 'f', -1, 32)
+	case float64:
+		return strconv.FormatFloat(v, 'f', -1, 64)
+	case complex64:
+		return `"` + strconv.FormatComplex(complex128(v), 'f', -1, 64) + `"`
+	case complex128:
+		return `"` + strconv.FormatComplex(v, 'f', -1, 128) + `"`
+	case PseudoStruct:
+		buf := bytes.NewBuffer(make([]byte, 0, 1024))
+		v = f.sanitize(v)
+		if flags&flagRawStruct == 0 {
+			buf.WriteByte('{')
+		}
+		for i := 0; i < len(v); i += 2 {
+			if i > 0 {
+				buf.WriteByte(',')
+			}
+			k, _ := v[i].(string) // sanitize() above means no need to check success
+			// arbitrary keys might need escaping
+			buf.WriteString(prettyString(k))
+			buf.WriteByte(':')
+			buf.WriteString(f.prettyWithFlags(v[i+1], 0, depth+1))
+		}
+		if flags&flagRawStruct == 0 {
+			buf.WriteByte('}')
+		}
+		return buf.String()
+	}
+
+	buf := bytes.NewBuffer(make([]byte, 0, 256))
+	t := reflect.TypeOf(value)
+	if t == nil {
+		return "null"
+	}
+	v := reflect.ValueOf(value)
+	switch t.Kind() {
+	case reflect.Bool:
+		return strconv.FormatBool(v.Bool())
+	case reflect.String:
+		return prettyString(v.String())
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return strconv.FormatInt(int64(v.Int()), 10)
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return strconv.FormatUint(uint64(v.Uint()), 10)
+	case reflect.Float32:
+		return strconv.FormatFloat(float64(v.Float()), 'f', -1, 32)
+	case reflect.Float64:
+		return strconv.FormatFloat(v.Float(), 'f', -1, 64)
+	case reflect.Complex64:
+		return `"` + strconv.FormatComplex(complex128(v.Complex()), 'f', -1, 64) + `"`
+	case reflect.Complex128:
+		return `"` + strconv.FormatComplex(v.Complex(), 'f', -1, 128) + `"`
+	case reflect.Struct:
+		if flags&flagRawStruct == 0 {
+			buf.WriteByte('{')
+		}
+		for i := 0; i < t.NumField(); i++ {
+			fld := t.Field(i)
+			if fld.PkgPath != "" {
+				// reflect says this field is only defined for non-exported fields.
+				continue
+			}
+			if !v.Field(i).CanInterface() {
+				// reflect isn't clear exactly what this means, but we can't use it.
+				continue
+			}
+			name := ""
+			omitempty := false
+			if tag, found := fld.Tag.Lookup("json"); found {
+				if tag == "-" {
+					continue
+				}
+				if comma := strings.Index(tag, ","); comma != -1 {
+					if n := tag[:comma]; n != "" {
+						name = n
+					}
+					rest := tag[comma:]
+					if strings.Contains(rest, ",omitempty,") || strings.HasSuffix(rest, ",omitempty") {
+						omitempty = true
+					}
+				} else {
+					name = tag
+				}
+			}
+			if omitempty && isEmpty(v.Field(i)) {
+				continue
+			}
+			if i > 0 {
+				buf.WriteByte(',')
+			}
+			if fld.Anonymous && fld.Type.Kind() == reflect.Struct && name == "" {
+				buf.WriteString(f.prettyWithFlags(v.Field(i).Interface(), flags|flagRawStruct, depth+1))
+				continue
+			}
+			if name == "" {
+				name = fld.Name
+			}
+			// field names can't contain characters which need escaping
+			buf.WriteByte('"')
+			buf.WriteString(name)
+			buf.WriteByte('"')
+			buf.WriteByte(':')
+			buf.WriteString(f.prettyWithFlags(v.Field(i).Interface(), 0, depth+1))
+		}
+		if flags&flagRawStruct == 0 {
+			buf.WriteByte('}')
+		}
+		return buf.String()
+	case reflect.Slice, reflect.Array:
+		buf.WriteByte('[')
+		for i := 0; i < v.Len(); i++ {
+			if i > 0 {
+				buf.WriteByte(',')
+			}
+			e := v.Index(i)
+			buf.WriteString(f.prettyWithFlags(e.Interface(), 0, depth+1))
+		}
+		buf.WriteByte(']')
+		return buf.String()
+	case reflect.Map:
+		buf.WriteByte('{')
+		// This does not sort the map keys, for best perf.
+		it := v.MapRange()
+		i := 0
+		for it.Next() {
+			if i > 0 {
+				buf.WriteByte(',')
+			}
+			// If a map key supports TextMarshaler, use it.
+			keystr := ""
+			if m, ok := it.Key().Interface().(encoding.TextMarshaler); ok {
+				txt, err := m.MarshalText()
+				if err != nil {
+					keystr = fmt.Sprintf("<error-MarshalText: %s>", err.Error())
+				} else {
+					keystr = string(txt)
+				}
+				keystr = prettyString(keystr)
+			} else {
+				// prettyWithFlags will produce already-escaped values
+				keystr = f.prettyWithFlags(it.Key().Interface(), 0, depth+1)
+				if t.Key().Kind() != reflect.String {
+					// JSON only does string keys.  Unlike Go's standard JSON, we'll
+					// convert just about anything to a string.
+					keystr = prettyString(keystr)
+				}
+			}
+			buf.WriteString(keystr)
+			buf.WriteByte(':')
+			buf.WriteString(f.prettyWithFlags(it.Value().Interface(), 0, depth+1))
+			i++
+		}
+		buf.WriteByte('}')
+		return buf.String()
+	case reflect.Ptr, reflect.Interface:
+		if v.IsNil() {
+			return "null"
+		}
+		return f.prettyWithFlags(v.Elem().Interface(), 0, depth)
+	}
+	return fmt.Sprintf(`"<unhandled-%s>"`, t.Kind().String())
+}
+
+func prettyString(s string) string {
+	// Avoid escaping (which does allocations) if we can.
+	if needsEscape(s) {
+		return strconv.Quote(s)
+	}
+	b := bytes.NewBuffer(make([]byte, 0, 1024))
+	b.WriteByte('"')
+	b.WriteString(s)
+	b.WriteByte('"')
+	return b.String()
+}
+
+// needsEscape determines whether the input string needs to be escaped or not,
+// without doing any allocations.
+func needsEscape(s string) bool {
+	for _, r := range s {
+		if !strconv.IsPrint(r) || r == '\\' || r == '"' {
+			return true
+		}
+	}
+	return false
+}
+
+func isEmpty(v reflect.Value) bool {
+	switch v.Kind() {
+	case reflect.Array, reflect.Map, reflect.Slice, reflect.String:
+		return v.Len() == 0
+	case reflect.Bool:
+		return !v.Bool()
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return v.Int() == 0
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return v.Uint() == 0
+	case reflect.Float32, reflect.Float64:
+		return v.Float() == 0
+	case reflect.Complex64, reflect.Complex128:
+		return v.Complex() == 0
+	case reflect.Interface, reflect.Ptr:
+		return v.IsNil()
+	}
+	return false
+}
+
+func invokeMarshaler(m logr.Marshaler) (ret interface{}) {
+	defer func() {
+		if r := recover(); r != nil {
+			ret = fmt.Sprintf("<panic: %s>", r)
+		}
+	}()
+	return m.MarshalLog()
+}
+
+func invokeStringer(s fmt.Stringer) (ret string) {
+	defer func() {
+		if r := recover(); r != nil {
+			ret = fmt.Sprintf("<panic: %s>", r)
+		}
+	}()
+	return s.String()
+}
+
+func invokeError(e error) (ret string) {
+	defer func() {
+		if r := recover(); r != nil {
+			ret = fmt.Sprintf("<panic: %s>", r)
+		}
+	}()
+	return e.Error()
+}
+
+// Caller represents the original call site for a log line, after considering
+// logr.Logger.WithCallDepth and logr.Logger.WithCallStackHelper.  The File and
+// Line fields will always be provided, while the Func field is optional.
+// Users can set the render hook fields in Options to examine logged key-value
+// pairs, one of which will be {"caller", Caller} if the Options.LogCaller
+// field is enabled for the given MessageClass.
+type Caller struct {
+	// File is the basename of the file for this call site.
+	File string `json:"file"`
+	// Line is the line number in the file for this call site.
+	Line int `json:"line"`
+	// Func is the function name for this call site, or empty if
+	// Options.LogCallerFunc is not enabled.
+	Func string `json:"function,omitempty"`
+}
+
+func (f Formatter) caller() Caller {
+	// +1 for this frame, +1 for Info/Error.
+	pc, file, line, ok := runtime.Caller(f.depth + 2)
+	if !ok {
+		return Caller{"<unknown>", 0, ""}
+	}
+	fn := ""
+	if f.opts.LogCallerFunc {
+		if fp := runtime.FuncForPC(pc); fp != nil {
+			fn = fp.Name()
+		}
+	}
+
+	return Caller{filepath.Base(file), line, fn}
+}
+
+const noValue = "<no-value>"
+
+func (f Formatter) nonStringKey(v interface{}) string {
+	return fmt.Sprintf("<non-string-key: %s>", f.snippet(v))
+}
+
+// snippet produces a short snippet string of an arbitrary value.
+func (f Formatter) snippet(v interface{}) string {
+	const snipLen = 16
+
+	snip := f.pretty(v)
+	if len(snip) > snipLen {
+		snip = snip[:snipLen]
+	}
+	return snip
+}
+
+// sanitize ensures that a list of key-value pairs has a value for every key
+// (adding a value if needed) and that each key is a string (substituting a key
+// if needed).
+func (f Formatter) sanitize(kvList []interface{}) []interface{} {
+	if len(kvList)%2 != 0 {
+		kvList = append(kvList, noValue)
+	}
+	for i := 0; i < len(kvList); i += 2 {
+		_, ok := kvList[i].(string)
+		if !ok {
+			kvList[i] = f.nonStringKey(kvList[i])
+		}
+	}
+	return kvList
+}
+
+// Init configures this Formatter from runtime info, such as the call depth
+// imposed by logr itself.
+// Note that this receiver is a pointer, so depth can be saved.
+func (f *Formatter) Init(info logr.RuntimeInfo) {
+	f.depth += info.CallDepth
+}
+
+// Enabled checks whether an info message at the given level should be logged.
+func (f Formatter) Enabled(level int) bool {
+	return level <= f.opts.Verbosity
+}
+
+// GetDepth returns the current depth of this Formatter.  This is useful for
+// implementations which do their own caller attribution.
+func (f Formatter) GetDepth() int {
+	return f.depth
+}
+
+// FormatInfo renders an Info log message into strings.  The prefix will be
+// empty when no names were set (via AddNames), or when the output is
+// configured for JSON.
+func (f Formatter) FormatInfo(level int, msg string, kvList []interface{}) (prefix, argsStr string) {
+	args := make([]interface{}, 0, 64) // using a constant here impacts perf
+	prefix = f.prefix
+	if f.outputFormat == outputJSON {
+		args = append(args, "logger", prefix)
+		prefix = ""
+	}
+	if f.opts.LogTimestamp {
+		args = append(args, "ts", time.Now().Format(f.opts.TimestampFormat))
+	}
+	if policy := f.opts.LogCaller; policy == All || policy == Info {
+		args = append(args, "caller", f.caller())
+	}
+	args = append(args, "level", level, "msg", msg)
+	return prefix, f.render(args, kvList)
+}
+
+// FormatError renders an Error log message into strings.  The prefix will be
+// empty when no names were set (via AddNames),  or when the output is
+// configured for JSON.
+func (f Formatter) FormatError(err error, msg string, kvList []interface{}) (prefix, argsStr string) {
+	args := make([]interface{}, 0, 64) // using a constant here impacts perf
+	prefix = f.prefix
+	if f.outputFormat == outputJSON {
+		args = append(args, "logger", prefix)
+		prefix = ""
+	}
+	if f.opts.LogTimestamp {
+		args = append(args, "ts", time.Now().Format(f.opts.TimestampFormat))
+	}
+	if policy := f.opts.LogCaller; policy == All || policy == Error {
+		args = append(args, "caller", f.caller())
+	}
+	args = append(args, "msg", msg)
+	var loggableErr interface{}
+	if err != nil {
+		loggableErr = err.Error()
+	}
+	args = append(args, "error", loggableErr)
+	return f.prefix, f.render(args, kvList)
+}
+
+// AddName appends the specified name.  funcr uses '/' characters to separate
+// name elements.  Callers should not pass '/' in the provided name string, but
+// this library does not actually enforce that.
+func (f *Formatter) AddName(name string) {
+	if len(f.prefix) > 0 {
+		f.prefix += "/"
+	}
+	f.prefix += name
+}
+
+// AddValues adds key-value pairs to the set of saved values to be logged with
+// each log line.
+func (f *Formatter) AddValues(kvList []interface{}) {
+	// Three slice args forces a copy.
+	n := len(f.values)
+	f.values = append(f.values[:n:n], kvList...)
+
+	vals := f.values
+	if hook := f.opts.RenderValuesHook; hook != nil {
+		vals = hook(f.sanitize(vals))
+	}
+
+	// Pre-render values, so we don't have to do it on each Info/Error call.
+	buf := bytes.NewBuffer(make([]byte, 0, 1024))
+	f.flatten(buf, vals, false, true) // escape user-provided keys
+	f.valuesStr = buf.String()
+}
+
+// AddCallDepth increases the number of stack-frames to skip when attributing
+// the log line to a file and line.
+func (f *Formatter) AddCallDepth(depth int) {
+	f.depth += depth
+}

vendor/github.com/go-logr/logr/logr.go

@@ -0,0 +1,510 @@
+/*
+Copyright 2019 The logr Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// This design derives from Dave Cheney's blog:
+//     http://dave.cheney.net/2015/11/05/lets-talk-about-logging
+
+// Package logr defines a general-purpose logging API and abstract interfaces
+// to back that API.  Packages in the Go ecosystem can depend on this package,
+// while callers can implement logging with whatever backend is appropriate.
+//
+// Usage
+//
+// Logging is done using a Logger instance.  Logger is a concrete type with
+// methods, which defers the actual logging to a LogSink interface.  The main
+// methods of Logger are Info() and Error().  Arguments to Info() and Error()
+// are key/value pairs rather than printf-style formatted strings, emphasizing
+// "structured logging".
+//
+// With Go's standard log package, we might write:
+//   log.Printf("setting target value %s", targetValue)
+//
+// With logr's structured logging, we'd write:
+//   logger.Info("setting target", "value", targetValue)
+//
+// Errors are much the same.  Instead of:
+//   log.Printf("failed to open the pod bay door for user %s: %v", user, err)
+//
+// We'd write:
+//   logger.Error(err, "failed to open the pod bay door", "user", user)
+//
+// Info() and Error() are very similar, but they are separate methods so that
+// LogSink implementations can choose to do things like attach additional
+// information (such as stack traces) on calls to Error(). Error() messages are
+// always logged, regardless of the current verbosity.  If there is no error
+// instance available, passing nil is valid.
+//
+// Verbosity
+//
+// Often we want to log information only when the application in "verbose
+// mode".  To write log lines that are more verbose, Logger has a V() method.
+// The higher the V-level of a log line, the less critical it is considered.
+// Log-lines with V-levels that are not enabled (as per the LogSink) will not
+// be written.  Level V(0) is the default, and logger.V(0).Info() has the same
+// meaning as logger.Info().  Negative V-levels have the same meaning as V(0).
+// Error messages do not have a verbosity level and are always logged.
+//
+// Where we might have written:
+//   if flVerbose >= 2 {
+//       log.Printf("an unusual thing happened")
+//   }
+//
+// We can write:
+//   logger.V(2).Info("an unusual thing happened")
+//
+// Logger Names
+//
+// Logger instances can have name strings so that all messages logged through
+// that instance have additional context.  For example, you might want to add
+// a subsystem name:
+//
+//   logger.WithName("compactor").Info("started", "time", time.Now())
+//
+// The WithName() method returns a new Logger, which can be passed to
+// constructors or other functions for further use.  Repeated use of WithName()
+// will accumulate name "segments".  These name segments will be joined in some
+// way by the LogSink implementation.  It is strongly recommended that name
+// segments contain simple identifiers (letters, digits, and hyphen), and do
+// not contain characters that could muddle the log output or confuse the
+// joining operation (e.g. whitespace, commas, periods, slashes, brackets,
+// quotes, etc).
+//
+// Saved Values
+//
+// Logger instances can store any number of key/value pairs, which will be
+// logged alongside all messages logged through that instance.  For example,
+// you might want to create a Logger instance per managed object:
+//
+// With the standard log package, we might write:
+//   log.Printf("decided to set field foo to value %q for object %s/%s",
+//       targetValue, object.Namespace, object.Name)
+//
+// With logr we'd write:
+//   // Elsewhere: set up the logger to log the object name.
+//   obj.logger = mainLogger.WithValues(
+//       "name", obj.name, "namespace", obj.namespace)
+//
+//   // later on...
+//   obj.logger.Info("setting foo", "value", targetValue)
+//
+// Best Practices
+//
+// Logger has very few hard rules, with the goal that LogSink implementations
+// might have a lot of freedom to differentiate.  There are, however, some
+// things to consider.
+//
+// The log message consists of a constant message attached to the log line.
+// This should generally be a simple description of what's occurring, and should
+// never be a format string.  Variable information can then be attached using
+// named values.
+//
+// Keys are arbitrary strings, but should generally be constant values.  Values
+// may be any Go value, but how the value is formatted is determined by the
+// LogSink implementation.
+//
+// Logger instances are meant to be passed around by value. Code that receives
+// such a value can call its methods without having to check whether the
+// instance is ready for use.
+//
+// Calling methods with the null logger (Logger{}) as instance will crash
+// because it has no LogSink. Therefore this null logger should never be passed
+// around. For cases where passing a logger is optional, a pointer to Logger
+// should be used.
+//
+// Key Naming Conventions
+//
+// Keys are not strictly required to conform to any specification or regex, but
+// it is recommended that they:
+//   * be human-readable and meaningful (not auto-generated or simple ordinals)
+//   * be constant (not dependent on input data)
+//   * contain only printable characters
+//   * not contain whitespace or punctuation
+//   * use lower case for simple keys and lowerCamelCase for more complex ones
+//
+// These guidelines help ensure that log data is processed properly regardless
+// of the log implementation.  For example, log implementations will try to
+// output JSON data or will store data for later database (e.g. SQL) queries.
+//
+// While users are generally free to use key names of their choice, it's
+// generally best to avoid using the following keys, as they're frequently used
+// by implementations:
+//   * "caller": the calling information (file/line) of a particular log line
+//   * "error": the underlying error value in the `Error` method
+//   * "level": the log level
+//   * "logger": the name of the associated logger
+//   * "msg": the log message
+//   * "stacktrace": the stack trace associated with a particular log line or
+//                   error (often from the `Error` message)
+//   * "ts": the timestamp for a log line
+//
+// Implementations are encouraged to make use of these keys to represent the
+// above concepts, when necessary (for example, in a pure-JSON output form, it
+// would be necessary to represent at least message and timestamp as ordinary
+// named values).
+//
+// Break Glass
+//
+// Implementations may choose to give callers access to the underlying
+// logging implementation.  The recommended pattern for this is:
+//   // Underlier exposes access to the underlying logging implementation.
+//   // Since callers only have a logr.Logger, they have to know which
+//   // implementation is in use, so this interface is less of an abstraction
+//   // and more of way to test type conversion.
+//   type Underlier interface {
+//       GetUnderlying() <underlying-type>
+//   }
+//
+// Logger grants access to the sink to enable type assertions like this:
+//   func DoSomethingWithImpl(log logr.Logger) {
+//       if underlier, ok := log.GetSink()(impl.Underlier) {
+//          implLogger := underlier.GetUnderlying()
+//          ...
+//       }
+//   }
+//
+// Custom `With*` functions can be implemented by copying the complete
+// Logger struct and replacing the sink in the copy:
+//   // WithFooBar changes the foobar parameter in the log sink and returns a
+//   // new logger with that modified sink.  It does nothing for loggers where
+//   // the sink doesn't support that parameter.
+//   func WithFoobar(log logr.Logger, foobar int) logr.Logger {
+//      if foobarLogSink, ok := log.GetSink()(FoobarSink); ok {
+//         log = log.WithSink(foobarLogSink.WithFooBar(foobar))
+//      }
+//      return log
+//   }
+//
+// Don't use New to construct a new Logger with a LogSink retrieved from an
+// existing Logger. Source code attribution might not work correctly and
+// unexported fields in Logger get lost.
+//
+// Beware that the same LogSink instance may be shared by different logger
+// instances. Calling functions that modify the LogSink will affect all of
+// those.
+package logr
+
+import (
+	"context"
+)
+
+// New returns a new Logger instance.  This is primarily used by libraries
+// implementing LogSink, rather than end users.
+func New(sink LogSink) Logger {
+	logger := Logger{}
+	logger.setSink(sink)
+	sink.Init(runtimeInfo)
+	return logger
+}
+
+// setSink stores the sink and updates any related fields. It mutates the
+// logger and thus is only safe to use for loggers that are not currently being
+// used concurrently.
+func (l *Logger) setSink(sink LogSink) {
+	l.sink = sink
+}
+
+// GetSink returns the stored sink.
+func (l Logger) GetSink() LogSink {
+	return l.sink
+}
+
+// WithSink returns a copy of the logger with the new sink.
+func (l Logger) WithSink(sink LogSink) Logger {
+	l.setSink(sink)
+	return l
+}
+
+// Logger is an interface to an abstract logging implementation.  This is a
+// concrete type for performance reasons, but all the real work is passed on to
+// a LogSink.  Implementations of LogSink should provide their own constructors
+// that return Logger, not LogSink.
+//
+// The underlying sink can be accessed through GetSink and be modified through
+// WithSink. This enables the implementation of custom extensions (see "Break
+// Glass" in the package documentation). Normally the sink should be used only
+// indirectly.
+type Logger struct {
+	sink  LogSink
+	level int
+}
+
+// Enabled tests whether this Logger is enabled.  For example, commandline
+// flags might be used to set the logging verbosity and disable some info logs.
+func (l Logger) Enabled() bool {
+	return l.sink.Enabled(l.level)
+}
+
+// Info logs a non-error message with the given key/value pairs as context.
+//
+// The msg argument should be used to add some constant description to the log
+// line.  The key/value pairs can then be used to add additional variable
+// information.  The key/value pairs must alternate string keys and arbitrary
+// values.
+func (l Logger) Info(msg string, keysAndValues ...interface{}) {
+	if l.Enabled() {
+		if withHelper, ok := l.sink.(CallStackHelperLogSink); ok {
+			withHelper.GetCallStackHelper()()
+		}
+		l.sink.Info(l.level, msg, keysAndValues...)
+	}
+}
+
+// Error logs an error, with the given message and key/value pairs as context.
+// It functions similarly to Info, but may have unique behavior, and should be
+// preferred for logging errors (see the package documentations for more
+// information). The log message will always be emitted, regardless of
+// verbosity level.
+//
+// The msg argument should be used to add context to any underlying error,
+// while the err argument should be used to attach the actual error that
+// triggered this log line, if present. The err parameter is optional
+// and nil may be passed instead of an error instance.
+func (l Logger) Error(err error, msg string, keysAndValues ...interface{}) {
+	if withHelper, ok := l.sink.(CallStackHelperLogSink); ok {
+		withHelper.GetCallStackHelper()()
+	}
+	l.sink.Error(err, msg, keysAndValues...)
+}
+
+// V returns a new Logger instance for a specific verbosity level, relative to
+// this Logger.  In other words, V-levels are additive.  A higher verbosity
+// level means a log message is less important.  Negative V-levels are treated
+// as 0.
+func (l Logger) V(level int) Logger {
+	if level < 0 {
+		level = 0
+	}
+	l.level += level
+	return l
+}
+
+// WithValues returns a new Logger instance with additional key/value pairs.
+// See Info for documentation on how key/value pairs work.
+func (l Logger) WithValues(keysAndValues ...interface{}) Logger {
+	l.setSink(l.sink.WithValues(keysAndValues...))
+	return l
+}
+
+// WithName returns a new Logger instance with the specified name element added
+// to the Logger's name.  Successive calls with WithName append additional
+// suffixes to the Logger's name.  It's strongly recommended that name segments
+// contain only letters, digits, and hyphens (see the package documentation for
+// more information).
+func (l Logger) WithName(name string) Logger {
+	l.setSink(l.sink.WithName(name))
+	return l
+}
+
+// WithCallDepth returns a Logger instance that offsets the call stack by the
+// specified number of frames when logging call site information, if possible.
+// This is useful for users who have helper functions between the "real" call
+// site and the actual calls to Logger methods.  If depth is 0 the attribution
+// should be to the direct caller of this function.  If depth is 1 the
+// attribution should skip 1 call frame, and so on.  Successive calls to this
+// are additive.
+//
+// If the underlying log implementation supports a WithCallDepth(int) method,
+// it will be called and the result returned.  If the implementation does not
+// support CallDepthLogSink, the original Logger will be returned.
+//
+// To skip one level, WithCallStackHelper() should be used instead of
+// WithCallDepth(1) because it works with implementions that support the
+// CallDepthLogSink and/or CallStackHelperLogSink interfaces.
+func (l Logger) WithCallDepth(depth int) Logger {
+	if withCallDepth, ok := l.sink.(CallDepthLogSink); ok {
+		l.setSink(withCallDepth.WithCallDepth(depth))
+	}
+	return l
+}
+
+// WithCallStackHelper returns a new Logger instance that skips the direct
+// caller when logging call site information, if possible.  This is useful for
+// users who have helper functions between the "real" call site and the actual
+// calls to Logger methods and want to support loggers which depend on marking
+// each individual helper function, like loggers based on testing.T.
+//
+// In addition to using that new logger instance, callers also must call the
+// returned function.
+//
+// If the underlying log implementation supports a WithCallDepth(int) method,
+// WithCallDepth(1) will be called to produce a new logger. If it supports a
+// WithCallStackHelper() method, that will be also called. If the
+// implementation does not support either of these, the original Logger will be
+// returned.
+func (l Logger) WithCallStackHelper() (func(), Logger) {
+	var helper func()
+	if withCallDepth, ok := l.sink.(CallDepthLogSink); ok {
+		l.setSink(withCallDepth.WithCallDepth(1))
+	}
+	if withHelper, ok := l.sink.(CallStackHelperLogSink); ok {
+		helper = withHelper.GetCallStackHelper()
+	} else {
+		helper = func() {}
+	}
+	return helper, l
+}
+
+// contextKey is how we find Loggers in a context.Context.
+type contextKey struct{}
+
+// FromContext returns a Logger from ctx or an error if no Logger is found.
+func FromContext(ctx context.Context) (Logger, error) {
+	if v, ok := ctx.Value(contextKey{}).(Logger); ok {
+		return v, nil
+	}
+
+	return Logger{}, notFoundError{}
+}
+
+// notFoundError exists to carry an IsNotFound method.
+type notFoundError struct{}
+
+func (notFoundError) Error() string {
+	return "no logr.Logger was present"
+}
+
+func (notFoundError) IsNotFound() bool {
+	return true
+}
+
+// FromContextOrDiscard returns a Logger from ctx.  If no Logger is found, this
+// returns a Logger that discards all log messages.
+func FromContextOrDiscard(ctx context.Context) Logger {
+	if v, ok := ctx.Value(contextKey{}).(Logger); ok {
+		return v
+	}
+
+	return Discard()
+}
+
+// NewContext returns a new Context, derived from ctx, which carries the
+// provided Logger.
+func NewContext(ctx context.Context, logger Logger) context.Context {
+	return context.WithValue(ctx, contextKey{}, logger)
+}
+
+// RuntimeInfo holds information that the logr "core" library knows which
+// LogSinks might want to know.
+type RuntimeInfo struct {
+	// CallDepth is the number of call frames the logr library adds between the
+	// end-user and the LogSink.  LogSink implementations which choose to print
+	// the original logging site (e.g. file & line) should climb this many
+	// additional frames to find it.
+	CallDepth int
+}
+
+// runtimeInfo is a static global.  It must not be changed at run time.
+var runtimeInfo = RuntimeInfo{
+	CallDepth: 1,
+}
+
+// LogSink represents a logging implementation.  End-users will generally not
+// interact with this type.
+type LogSink interface {
+	// Init receives optional information about the logr library for LogSink
+	// implementations that need it.
+	Init(info RuntimeInfo)
+
+	// Enabled tests whether this LogSink is enabled at the specified V-level.
+	// For example, commandline flags might be used to set the logging
+	// verbosity and disable some info logs.
+	Enabled(level int) bool
+
+	// Info logs a non-error message with the given key/value pairs as context.
+	// The level argument is provided for optional logging.  This method will
+	// only be called when Enabled(level) is true. See Logger.Info for more
+	// details.
+	Info(level int, msg string, keysAndValues ...interface{})
+
+	// Error logs an error, with the given message and key/value pairs as
+	// context.  See Logger.Error for more details.
+	Error(err error, msg string, keysAndValues ...interface{})
+
+	// WithValues returns a new LogSink with additional key/value pairs.  See
+	// Logger.WithValues for more details.
+	WithValues(keysAndValues ...interface{}) LogSink
+
+	// WithName returns a new LogSink with the specified name appended.  See
+	// Logger.WithName for more details.
+	WithName(name string) LogSink
+}
+
+// CallDepthLogSink represents a Logger that knows how to climb the call stack
+// to identify the original call site and can offset the depth by a specified
+// number of frames.  This is useful for users who have helper functions
+// between the "real" call site and the actual calls to Logger methods.
+// Implementations that log information about the call site (such as file,
+// function, or line) would otherwise log information about the intermediate
+// helper functions.
+//
+// This is an optional interface and implementations are not required to
+// support it.
+type CallDepthLogSink interface {
+	// WithCallDepth returns a LogSink that will offset the call
+	// stack by the specified number of frames when logging call
+	// site information.
+	//
+	// If depth is 0, the LogSink should skip exactly the number
+	// of call frames defined in RuntimeInfo.CallDepth when Info
+	// or Error are called, i.e. the attribution should be to the
+	// direct caller of Logger.Info or Logger.Error.
+	//
+	// If depth is 1 the attribution should skip 1 call frame, and so on.
+	// Successive calls to this are additive.
+	WithCallDepth(depth int) LogSink
+}
+
+// CallStackHelperLogSink represents a Logger that knows how to climb
+// the call stack to identify the original call site and can skip
+// intermediate helper functions if they mark themselves as
+// helper. Go's testing package uses that approach.
+//
+// This is useful for users who have helper functions between the
+// "real" call site and the actual calls to Logger methods.
+// Implementations that log information about the call site (such as
+// file, function, or line) would otherwise log information about the
+// intermediate helper functions.
+//
+// This is an optional interface and implementations are not required
+// to support it. Implementations that choose to support this must not
+// simply implement it as WithCallDepth(1), because
+// Logger.WithCallStackHelper will call both methods if they are
+// present. This should only be implemented for LogSinks that actually
+// need it, as with testing.T.
+type CallStackHelperLogSink interface {
+	// GetCallStackHelper returns a function that must be called
+	// to mark the direct caller as helper function when logging
+	// call site information.
+	GetCallStackHelper() func()
+}
+
+// Marshaler is an optional interface that logged values may choose to
+// implement. Loggers with structured output, such as JSON, should
+// log the object return by the MarshalLog method instead of the
+// original value.
+type Marshaler interface {
+	// MarshalLog can be used to:
+	//   - ensure that structs are not logged as strings when the original
+	//     value has a String method: return a different type without a
+	//     String method
+	//   - select which fields of a complex type should get logged:
+	//     return a simpler struct with fewer fields
+	//   - log unexported fields: return a different struct
+	//     with exported fields
+	//
+	// It may return any value of any type.
+	MarshalLog() interface{}
+}

vendor/github.com/go-logr/stdr/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
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+      and distribution as defined by Sections 1 through 9 of this document.
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+
+      "You" (or "Your") shall mean an individual or Legal Entity
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+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
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+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
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+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
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+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
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+      on Your own behalf and on Your sole responsibility, not on behalf
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+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
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+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
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+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/github.com/go-logr/stdr/README.md

@@ -0,0 +1,6 @@
+# Minimal Go logging using logr and Go's standard library
+
+[![Go Reference](https://pkg.go.dev/badge/github.com/go-logr/stdr.svg)](https://pkg.go.dev/github.com/go-logr/stdr)
+
+This package implements the [logr interface](https://github.com/go-logr/logr)
+in terms of Go's standard log package(https://pkg.go.dev/log).

vendor/github.com/go-logr/stdr/stdr.go

@@ -0,0 +1,170 @@
+/*
+Copyright 2019 The logr Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Package stdr implements github.com/go-logr/logr.Logger in terms of
+// Go's standard log package.
+package stdr
+
+import (
+	"log"
+	"os"
+
+	"github.com/go-logr/logr"
+	"github.com/go-logr/logr/funcr"
+)
+
+// The global verbosity level.  See SetVerbosity().
+var globalVerbosity int
+
+// SetVerbosity sets the global level against which all info logs will be
+// compared.  If this is greater than or equal to the "V" of the logger, the
+// message will be logged.  A higher value here means more logs will be written.
+// The previous verbosity value is returned.  This is not concurrent-safe -
+// callers must be sure to call it from only one goroutine.
+func SetVerbosity(v int) int {
+	old := globalVerbosity
+	globalVerbosity = v
+	return old
+}
+
+// New returns a logr.Logger which is implemented by Go's standard log package,
+// or something like it.  If std is nil, this will use a default logger
+// instead.
+//
+// Example: stdr.New(log.New(os.Stderr, "", log.LstdFlags|log.Lshortfile)))
+func New(std StdLogger) logr.Logger {
+	return NewWithOptions(std, Options{})
+}
+
+// NewWithOptions returns a logr.Logger which is implemented by Go's standard
+// log package, or something like it.  See New for details.
+func NewWithOptions(std StdLogger, opts Options) logr.Logger {
+	if std == nil {
+		// Go's log.Default() is only available in 1.16 and higher.
+		std = log.New(os.Stderr, "", log.LstdFlags)
+	}
+
+	if opts.Depth < 0 {
+		opts.Depth = 0
+	}
+
+	fopts := funcr.Options{
+		LogCaller: funcr.MessageClass(opts.LogCaller),
+	}
+
+	sl := &logger{
+		Formatter: funcr.NewFormatter(fopts),
+		std:       std,
+	}
+
+	// For skipping our own logger.Info/Error.
+	sl.Formatter.AddCallDepth(1 + opts.Depth)
+
+	return logr.New(sl)
+}
+
+// Options carries parameters which influence the way logs are generated.
+type Options struct {
+	// Depth biases the assumed number of call frames to the "true" caller.
+	// This is useful when the calling code calls a function which then calls
+	// stdr (e.g. a logging shim to another API).  Values less than zero will
+	// be treated as zero.
+	Depth int
+
+	// LogCaller tells stdr to add a "caller" key to some or all log lines.
+	// Go's log package has options to log this natively, too.
+	LogCaller MessageClass
+
+	// TODO: add an option to log the date/time
+}
+
+// MessageClass indicates which category or categories of messages to consider.
+type MessageClass int
+
+const (
+	// None ignores all message classes.
+	None MessageClass = iota
+	// All considers all message classes.
+	All
+	// Info only considers info messages.
+	Info
+	// Error only considers error messages.
+	Error
+)
+
+// StdLogger is the subset of the Go stdlib log.Logger API that is needed for
+// this adapter.
+type StdLogger interface {
+	// Output is the same as log.Output and log.Logger.Output.
+	Output(calldepth int, logline string) error
+}
+
+type logger struct {
+	funcr.Formatter
+	std StdLogger
+}
+
+var _ logr.LogSink = &logger{}
+var _ logr.CallDepthLogSink = &logger{}
+
+func (l logger) Enabled(level int) bool {
+	return globalVerbosity >= level
+}
+
+func (l logger) Info(level int, msg string, kvList ...interface{}) {
+	prefix, args := l.FormatInfo(level, msg, kvList)
+	if prefix != "" {
+		args = prefix + ": " + args
+	}
+	_ = l.std.Output(l.Formatter.GetDepth()+1, args)
+}
+
+func (l logger) Error(err error, msg string, kvList ...interface{}) {
+	prefix, args := l.FormatError(err, msg, kvList)
+	if prefix != "" {
+		args = prefix + ": " + args
+	}
+	_ = l.std.Output(l.Formatter.GetDepth()+1, args)
+}
+
+func (l logger) WithName(name string) logr.LogSink {
+	l.Formatter.AddName(name)
+	return &l
+}
+
+func (l logger) WithValues(kvList ...interface{}) logr.LogSink {
+	l.Formatter.AddValues(kvList)
+	return &l
+}
+
+func (l logger) WithCallDepth(depth int) logr.LogSink {
+	l.Formatter.AddCallDepth(depth)
+	return &l
+}
+
+// Underlier exposes access to the underlying logging implementation.  Since
+// callers only have a logr.Logger, they have to know which implementation is
+// in use, so this interface is less of an abstraction and more of way to test
+// type conversion.
+type Underlier interface {
+	GetUnderlying() StdLogger
+}
+
+// GetUnderlying returns the StdLogger underneath this logger.  Since StdLogger
+// is itself an interface, the result may or may not be a Go log.Logger.
+func (l logger) GetUnderlying() StdLogger {
+	return l.std
+}

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
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+      other entities that control, are controlled by, or are under common
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+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
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+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
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+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
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+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
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+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
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+
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+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
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+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
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+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
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+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
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+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
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+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
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+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp/client.go

@@ -0,0 +1,61 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package otelhttp
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+)
+
+// DefaultClient is the default Client and is used by Get, Head, Post and PostForm.
+// Please be careful of intitialization order - for example, if you change
+// the global propagator, the DefaultClient might still be using the old one
+var DefaultClient = &http.Client{Transport: NewTransport(http.DefaultTransport)}
+
+// Get is a convenient replacement for http.Get that adds a span around the request.
+func Get(ctx context.Context, url string) (resp *http.Response, err error) {
+	req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
+	if err != nil {
+		return nil, err
+	}
+	return DefaultClient.Do(req)
+}
+
+// Head is a convenient replacement for http.Head that adds a span around the request.
+func Head(ctx context.Context, url string) (resp *http.Response, err error) {
+	req, err := http.NewRequestWithContext(ctx, "HEAD", url, nil)
+	if err != nil {
+		return nil, err
+	}
+	return DefaultClient.Do(req)
+}
+
+// Post is a convenient replacement for http.Post that adds a span around the request.
+func Post(ctx context.Context, url, contentType string, body io.Reader) (resp *http.Response, err error) {
+	req, err := http.NewRequestWithContext(ctx, "POST", url, body)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Content-Type", contentType)
+	return DefaultClient.Do(req)
+}
+
+// PostForm is a convenient replacement for http.PostForm that adds a span around the request.
+func PostForm(ctx context.Context, url string, data url.Values) (resp *http.Response, err error) {
+	return Post(ctx, url, "application/x-www-form-urlencoded", strings.NewReader(data.Encode()))
+}

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp/common.go

@@ -0,0 +1,46 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package otelhttp
+
+import (
+	"net/http"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/trace"
+)
+
+// Attribute keys that can be added to a span.
+const (
+	ReadBytesKey  = attribute.Key("http.read_bytes")  // if anything was read from the request body, the total number of bytes read
+	ReadErrorKey  = attribute.Key("http.read_error")  // If an error occurred while reading a request, the string of the error (io.EOF is not recorded)
+	WroteBytesKey = attribute.Key("http.wrote_bytes") // if anything was written to the response writer, the total number of bytes written
+	WriteErrorKey = attribute.Key("http.write_error") // if an error occurred while writing a reply, the string of the error (io.EOF is not recorded)
+)
+
+// Server HTTP metrics
+const (
+	RequestCount          = "http.server.request_count"           // Incoming request count total
+	RequestContentLength  = "http.server.request_content_length"  // Incoming request bytes total
+	ResponseContentLength = "http.server.response_content_length" // Incoming response bytes total
+	ServerLatency         = "http.server.duration"                // Incoming end to end duration, microseconds
+)
+
+// Filter is a predicate used to determine whether a given http.request should
+// be traced. A Filter must return true if the request should be traced.
+type Filter func(*http.Request) bool
+
+func newTracer(tp trace.TracerProvider) trace.Tracer {
+	return tp.Tracer(instrumentationName, trace.WithInstrumentationVersion(SemVersion()))
+}

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp/config.go

@@ -0,0 +1,187 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package otelhttp
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptrace"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/metric"
+	"go.opentelemetry.io/otel/metric/global"
+	"go.opentelemetry.io/otel/propagation"
+	"go.opentelemetry.io/otel/trace"
+)
+
+const (
+	instrumentationName = "go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
+)
+
+// config represents the configuration options available for the http.Handler
+// and http.Transport types.
+type config struct {
+	Tracer            trace.Tracer
+	Meter             metric.Meter
+	Propagators       propagation.TextMapPropagator
+	SpanStartOptions  []trace.SpanStartOption
+	ReadEvent         bool
+	WriteEvent        bool
+	Filters           []Filter
+	SpanNameFormatter func(string, *http.Request) string
+	ClientTrace       func(context.Context) *httptrace.ClientTrace
+
+	TracerProvider trace.TracerProvider
+	MeterProvider  metric.MeterProvider
+}
+
+// Option interface used for setting optional config properties.
+type Option interface {
+	apply(*config)
+}
+
+type optionFunc func(*config)
+
+func (o optionFunc) apply(c *config) {
+	o(c)
+}
+
+// newConfig creates a new config struct and applies opts to it.
+func newConfig(opts ...Option) *config {
+	c := &config{
+		Propagators:   otel.GetTextMapPropagator(),
+		MeterProvider: global.GetMeterProvider(),
+	}
+	for _, opt := range opts {
+		opt.apply(c)
+	}
+
+	// Tracer is only initialized if manually specified. Otherwise, can be passed with the tracing context.
+	if c.TracerProvider != nil {
+		c.Tracer = newTracer(c.TracerProvider)
+	}
+
+	c.Meter = c.MeterProvider.Meter(
+		instrumentationName,
+		metric.WithInstrumentationVersion(SemVersion()),
+	)
+
+	return c
+}
+
+// WithTracerProvider specifies a tracer provider to use for creating a tracer.
+// If none is specified, the global provider is used.
+func WithTracerProvider(provider trace.TracerProvider) Option {
+	return optionFunc(func(cfg *config) {
+		if provider != nil {
+			cfg.TracerProvider = provider
+		}
+	})
+}
+
+// WithMeterProvider specifies a meter provider to use for creating a meter.
+// If none is specified, the global provider is used.
+func WithMeterProvider(provider metric.MeterProvider) Option {
+	return optionFunc(func(cfg *config) {
+		if provider != nil {
+			cfg.MeterProvider = provider
+		}
+	})
+}
+
+// WithPublicEndpoint configures the Handler to link the span with an incoming
+// span context. If this option is not provided, then the association is a child
+// association instead of a link.
+func WithPublicEndpoint() Option {
+	return optionFunc(func(c *config) {
+		c.SpanStartOptions = append(c.SpanStartOptions, trace.WithNewRoot())
+	})
+}
+
+// WithPropagators configures specific propagators. If this
+// option isn't specified, then the global TextMapPropagator is used.
+func WithPropagators(ps propagation.TextMapPropagator) Option {
+	return optionFunc(func(c *config) {
+		if ps != nil {
+			c.Propagators = ps
+		}
+	})
+}
+
+// WithSpanOptions configures an additional set of
+// trace.SpanOptions, which are applied to each new span.
+func WithSpanOptions(opts ...trace.SpanStartOption) Option {
+	return optionFunc(func(c *config) {
+		c.SpanStartOptions = append(c.SpanStartOptions, opts...)
+	})
+}
+
+// WithFilter adds a filter to the list of filters used by the handler.
+// If any filter indicates to exclude a request then the request will not be
+// traced. All filters must allow a request to be traced for a Span to be created.
+// If no filters are provided then all requests are traced.
+// Filters will be invoked for each processed request, it is advised to make them
+// simple and fast.
+func WithFilter(f Filter) Option {
+	return optionFunc(func(c *config) {
+		c.Filters = append(c.Filters, f)
+	})
+}
+
+type event int
+
+// Different types of events that can be recorded, see WithMessageEvents
+const (
+	ReadEvents event = iota
+	WriteEvents
+)
+
+// WithMessageEvents configures the Handler to record the specified events
+// (span.AddEvent) on spans. By default only summary attributes are added at the
+// end of the request.
+//
+// Valid events are:
+//     * ReadEvents: Record the number of bytes read after every http.Request.Body.Read
+//       using the ReadBytesKey
+//     * WriteEvents: Record the number of bytes written after every http.ResponeWriter.Write
+//       using the WriteBytesKey
+func WithMessageEvents(events ...event) Option {
+	return optionFunc(func(c *config) {
+		for _, e := range events {
+			switch e {
+			case ReadEvents:
+				c.ReadEvent = true
+			case WriteEvents:
+				c.WriteEvent = true
+			}
+		}
+	})
+}
+
+// WithSpanNameFormatter takes a function that will be called on every
+// request and the returned string will become the Span Name
+func WithSpanNameFormatter(f func(operation string, r *http.Request) string) Option {
+	return optionFunc(func(c *config) {
+		c.SpanNameFormatter = f
+	})
+}
+
+// WithClientTrace takes a function that returns client trace instance that will be
+// applied to the requests sent through the otelhttp Transport.
+func WithClientTrace(f func(context.Context) *httptrace.ClientTrace) Option {
+	return optionFunc(func(c *config) {
+		c.ClientTrace = f
+	})
+}

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp/doc.go

@@ -0,0 +1,18 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package otelhttp provides an http.Handler and functions that are intended
+// to be used to add tracing by wrapping existing handlers (with Handler) and
+// routes WithRouteTag.
+package otelhttp // import "go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp/handler.go

@@ -0,0 +1,236 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package otelhttp
+
+import (
+	"io"
+	"net/http"
+	"time"
+
+	"github.com/felixge/httpsnoop"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric"
+	"go.opentelemetry.io/otel/propagation"
+	semconv "go.opentelemetry.io/otel/semconv/v1.7.0"
+	"go.opentelemetry.io/otel/trace"
+)
+
+var _ http.Handler = &Handler{}
+
+// Handler is http middleware that corresponds to the http.Handler interface and
+// is designed to wrap a http.Mux (or equivalent), while individual routes on
+// the mux are wrapped with WithRouteTag. A Handler will add various attributes
+// to the span using the attribute.Keys defined in this package.
+type Handler struct {
+	operation string
+	handler   http.Handler
+
+	tracer            trace.Tracer
+	meter             metric.Meter
+	propagators       propagation.TextMapPropagator
+	spanStartOptions  []trace.SpanStartOption
+	readEvent         bool
+	writeEvent        bool
+	filters           []Filter
+	spanNameFormatter func(string, *http.Request) string
+	counters          map[string]metric.Int64Counter
+	valueRecorders    map[string]metric.Float64Histogram
+}
+
+func defaultHandlerFormatter(operation string, _ *http.Request) string {
+	return operation
+}
+
+// NewHandler wraps the passed handler, functioning like middleware, in a span
+// named after the operation and with any provided Options.
+func NewHandler(handler http.Handler, operation string, opts ...Option) http.Handler {
+	h := Handler{
+		handler:   handler,
+		operation: operation,
+	}
+
+	defaultOpts := []Option{
+		WithSpanOptions(trace.WithSpanKind(trace.SpanKindServer)),
+		WithSpanNameFormatter(defaultHandlerFormatter),
+	}
+
+	c := newConfig(append(defaultOpts, opts...)...)
+	h.configure(c)
+	h.createMeasures()
+
+	return &h
+}
+
+func (h *Handler) configure(c *config) {
+	h.tracer = c.Tracer
+	h.meter = c.Meter
+	h.propagators = c.Propagators
+	h.spanStartOptions = c.SpanStartOptions
+	h.readEvent = c.ReadEvent
+	h.writeEvent = c.WriteEvent
+	h.filters = c.Filters
+	h.spanNameFormatter = c.SpanNameFormatter
+}
+
+func handleErr(err error) {
+	if err != nil {
+		otel.Handle(err)
+	}
+}
+
+func (h *Handler) createMeasures() {
+	h.counters = make(map[string]metric.Int64Counter)
+	h.valueRecorders = make(map[string]metric.Float64Histogram)
+
+	requestBytesCounter, err := h.meter.NewInt64Counter(RequestContentLength)
+	handleErr(err)
+
+	responseBytesCounter, err := h.meter.NewInt64Counter(ResponseContentLength)
+	handleErr(err)
+
+	serverLatencyMeasure, err := h.meter.NewFloat64Histogram(ServerLatency)
+	handleErr(err)
+
+	h.counters[RequestContentLength] = requestBytesCounter
+	h.counters[ResponseContentLength] = responseBytesCounter
+	h.valueRecorders[ServerLatency] = serverLatencyMeasure
+}
+
+// ServeHTTP serves HTTP requests (http.Handler)
+func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	requestStartTime := time.Now()
+	for _, f := range h.filters {
+		if !f(r) {
+			// Simply pass through to the handler if a filter rejects the request
+			h.handler.ServeHTTP(w, r)
+			return
+		}
+	}
+
+	opts := append([]trace.SpanStartOption{
+		trace.WithAttributes(semconv.NetAttributesFromHTTPRequest("tcp", r)...),
+		trace.WithAttributes(semconv.EndUserAttributesFromHTTPRequest(r)...),
+		trace.WithAttributes(semconv.HTTPServerAttributesFromHTTPRequest(h.operation, "", r)...),
+	}, h.spanStartOptions...) // start with the configured options
+
+	tracer := h.tracer
+
+	if tracer == nil {
+		if span := trace.SpanFromContext(r.Context()); span.SpanContext().IsValid() {
+			tracer = newTracer(span.TracerProvider())
+		} else {
+			tracer = newTracer(otel.GetTracerProvider())
+		}
+	}
+
+	ctx := h.propagators.Extract(r.Context(), propagation.HeaderCarrier(r.Header))
+	ctx, span := tracer.Start(ctx, h.spanNameFormatter(h.operation, r), opts...)
+	defer span.End()
+
+	readRecordFunc := func(int64) {}
+	if h.readEvent {
+		readRecordFunc = func(n int64) {
+			span.AddEvent("read", trace.WithAttributes(ReadBytesKey.Int64(n)))
+		}
+	}
+
+	var bw bodyWrapper
+	// if request body is nil we don't want to mutate the body as it will affect
+	// the identity of it in a unforeseeable way because we assert ReadCloser
+	// fullfills a certain interface and it is indeed nil.
+	if r.Body != nil {
+		bw.ReadCloser = r.Body
+		bw.record = readRecordFunc
+		r.Body = &bw
+	}
+
+	writeRecordFunc := func(int64) {}
+	if h.writeEvent {
+		writeRecordFunc = func(n int64) {
+			span.AddEvent("write", trace.WithAttributes(WroteBytesKey.Int64(n)))
+		}
+	}
+
+	rww := &respWriterWrapper{ResponseWriter: w, record: writeRecordFunc, ctx: ctx, props: h.propagators}
+
+	// Wrap w to use our ResponseWriter methods while also exposing
+	// other interfaces that w may implement (http.CloseNotifier,
+	// http.Flusher, http.Hijacker, http.Pusher, io.ReaderFrom).
+
+	w = httpsnoop.Wrap(w, httpsnoop.Hooks{
+		Header: func(httpsnoop.HeaderFunc) httpsnoop.HeaderFunc {
+			return rww.Header
+		},
+		Write: func(httpsnoop.WriteFunc) httpsnoop.WriteFunc {
+			return rww.Write
+		},
+		WriteHeader: func(httpsnoop.WriteHeaderFunc) httpsnoop.WriteHeaderFunc {
+			return rww.WriteHeader
+		},
+	})
+
+	labeler := &Labeler{}
+	ctx = injectLabeler(ctx, labeler)
+
+	h.handler.ServeHTTP(w, r.WithContext(ctx))
+
+	setAfterServeAttributes(span, bw.read, rww.written, rww.statusCode, bw.err, rww.err)
+
+	// Add metrics
+	attributes := append(labeler.Get(), semconv.HTTPServerMetricAttributesFromHTTPRequest(h.operation, r)...)
+	h.counters[RequestContentLength].Add(ctx, bw.read, attributes...)
+	h.counters[ResponseContentLength].Add(ctx, rww.written, attributes...)
+
+	// Use floating point division here for higher precision (instead of Millisecond method).
+	elapsedTime := float64(time.Since(requestStartTime)) / float64(time.Millisecond)
+
+	h.valueRecorders[ServerLatency].Record(ctx, elapsedTime, attributes...)
+}
+
+func setAfterServeAttributes(span trace.Span, read, wrote int64, statusCode int, rerr, werr error) {
+	attributes := []attribute.KeyValue{}
+
+	// TODO: Consider adding an event after each read and write, possibly as an
+	// option (defaulting to off), so as to not create needlessly verbose spans.
+	if read > 0 {
+		attributes = append(attributes, ReadBytesKey.Int64(read))
+	}
+	if rerr != nil && rerr != io.EOF {
+		attributes = append(attributes, ReadErrorKey.String(rerr.Error()))
+	}
+	if wrote > 0 {
+		attributes = append(attributes, WroteBytesKey.Int64(wrote))
+	}
+	if statusCode > 0 {
+		attributes = append(attributes, semconv.HTTPAttributesFromHTTPStatusCode(statusCode)...)
+		span.SetStatus(semconv.SpanStatusFromHTTPStatusCode(statusCode))
+	}
+	if werr != nil && werr != io.EOF {
+		attributes = append(attributes, WriteErrorKey.String(werr.Error()))
+	}
+	span.SetAttributes(attributes...)
+}
+
+// WithRouteTag annotates a span with the provided route name using the
+// RouteKey Tag.
+func WithRouteTag(route string, h http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		span := trace.SpanFromContext(r.Context())
+		span.SetAttributes(semconv.HTTPRouteKey.String(route))
+		h.ServeHTTP(w, r)
+	})
+}

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp/labeler.go

@@ -0,0 +1,65 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package otelhttp
+
+import (
+	"context"
+	"sync"
+
+	"go.opentelemetry.io/otel/attribute"
+)
+
+// Labeler is used to allow instrumented HTTP handlers to add custom attributes to
+// the metrics recorded by the net/http instrumentation.
+type Labeler struct {
+	mu         sync.Mutex
+	attributes []attribute.KeyValue
+}
+
+// Add attributes to a Labeler.
+func (l *Labeler) Add(ls ...attribute.KeyValue) {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	l.attributes = append(l.attributes, ls...)
+}
+
+// Get returns a copy of the attributes added to the Labeler.
+func (l *Labeler) Get() []attribute.KeyValue {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	ret := make([]attribute.KeyValue, len(l.attributes))
+	copy(ret, l.attributes)
+	return ret
+}
+
+type labelerContextKeyType int
+
+const lablelerContextKey labelerContextKeyType = 0
+
+func injectLabeler(ctx context.Context, l *Labeler) context.Context {
+	return context.WithValue(ctx, lablelerContextKey, l)
+}
+
+// LabelerFromContext retrieves a Labeler instance from the provided context if
+// one is available.  If no Labeler was found in the provided context a new, empty
+// Labeler is returned and the second return value is false.  In this case it is
+// safe to use the Labeler but any attributes added to it will not be used.
+func LabelerFromContext(ctx context.Context) (*Labeler, bool) {
+	l, ok := ctx.Value(lablelerContextKey).(*Labeler)
+	if !ok {
+		l = &Labeler{}
+	}
+	return l, ok
+}

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp/transport.go

@@ -0,0 +1,190 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package otelhttp
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptrace"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/codes"
+	"go.opentelemetry.io/otel/propagation"
+	semconv "go.opentelemetry.io/otel/semconv/v1.7.0"
+	"go.opentelemetry.io/otel/trace"
+)
+
+// Transport implements the http.RoundTripper interface and wraps
+// outbound HTTP(S) requests with a span.
+type Transport struct {
+	rt http.RoundTripper
+
+	tracer            trace.Tracer
+	propagators       propagation.TextMapPropagator
+	spanStartOptions  []trace.SpanStartOption
+	filters           []Filter
+	spanNameFormatter func(string, *http.Request) string
+	clientTrace       func(context.Context) *httptrace.ClientTrace
+}
+
+var _ http.RoundTripper = &Transport{}
+
+// NewTransport wraps the provided http.RoundTripper with one that
+// starts a span and injects the span context into the outbound request headers.
+//
+// If the provided http.RoundTripper is nil, http.DefaultTransport will be used
+// as the base http.RoundTripper
+func NewTransport(base http.RoundTripper, opts ...Option) *Transport {
+	if base == nil {
+		base = http.DefaultTransport
+	}
+
+	t := Transport{
+		rt: base,
+	}
+
+	defaultOpts := []Option{
+		WithSpanOptions(trace.WithSpanKind(trace.SpanKindClient)),
+		WithSpanNameFormatter(defaultTransportFormatter),
+	}
+
+	c := newConfig(append(defaultOpts, opts...)...)
+	t.applyConfig(c)
+
+	return &t
+}
+
+func (t *Transport) applyConfig(c *config) {
+	t.tracer = c.Tracer
+	t.propagators = c.Propagators
+	t.spanStartOptions = c.SpanStartOptions
+	t.filters = c.Filters
+	t.spanNameFormatter = c.SpanNameFormatter
+	t.clientTrace = c.ClientTrace
+}
+
+func defaultTransportFormatter(_ string, r *http.Request) string {
+	return "HTTP " + r.Method
+}
+
+// RoundTrip creates a Span and propagates its context via the provided request's headers
+// before handing the request to the configured base RoundTripper. The created span will
+// end when the response body is closed or when a read from the body returns io.EOF.
+func (t *Transport) RoundTrip(r *http.Request) (*http.Response, error) {
+	for _, f := range t.filters {
+		if !f(r) {
+			// Simply pass through to the base RoundTripper if a filter rejects the request
+			return t.rt.RoundTrip(r)
+		}
+	}
+
+	tracer := t.tracer
+
+	if tracer == nil {
+		if span := trace.SpanFromContext(r.Context()); span.SpanContext().IsValid() {
+			tracer = newTracer(span.TracerProvider())
+		} else {
+			tracer = newTracer(otel.GetTracerProvider())
+		}
+	}
+
+	opts := append([]trace.SpanStartOption{}, t.spanStartOptions...) // start with the configured options
+
+	ctx, span := tracer.Start(r.Context(), t.spanNameFormatter("", r), opts...)
+
+	if t.clientTrace != nil {
+		ctx = httptrace.WithClientTrace(ctx, t.clientTrace(ctx))
+	}
+
+	r = r.WithContext(ctx)
+	span.SetAttributes(semconv.HTTPClientAttributesFromHTTPRequest(r)...)
+	t.propagators.Inject(ctx, propagation.HeaderCarrier(r.Header))
+
+	res, err := t.rt.RoundTrip(r)
+	if err != nil {
+		span.RecordError(err)
+		span.SetStatus(codes.Error, err.Error())
+		span.End()
+		return res, err
+	}
+
+	span.SetAttributes(semconv.HTTPAttributesFromHTTPStatusCode(res.StatusCode)...)
+	span.SetStatus(semconv.SpanStatusFromHTTPStatusCode(res.StatusCode))
+	res.Body = newWrappedBody(span, res.Body)
+
+	return res, err
+}
+
+// newWrappedBody returns a new and appropriately scoped *wrappedBody as an
+// io.ReadCloser. If the passed body implements io.Writer, the returned value
+// will implement io.ReadWriteCloser.
+func newWrappedBody(span trace.Span, body io.ReadCloser) io.ReadCloser {
+	// The successful protocol switch responses will have a body that
+	// implement an io.ReadWriteCloser. Ensure this interface type continues
+	// to be satisfied if that is the case.
+	if _, ok := body.(io.ReadWriteCloser); ok {
+		return &wrappedBody{span: span, body: body}
+	}
+
+	// Remove the implementation of the io.ReadWriteCloser and only implement
+	// the io.ReadCloser.
+	return struct{ io.ReadCloser }{&wrappedBody{span: span, body: body}}
+}
+
+// wrappedBody is the response body type returned by the transport
+// instrumentation to complete a span. Errors encountered when using the
+// response body are recorded in span tracking the response.
+//
+// The span tracking the response is ended when this body is closed.
+//
+// If the response body implements the io.Writer interface (i.e. for
+// successful protocol switches), the wrapped body also will.
+type wrappedBody struct {
+	span trace.Span
+	body io.ReadCloser
+}
+
+var _ io.ReadWriteCloser = &wrappedBody{}
+
+func (wb *wrappedBody) Write(p []byte) (int, error) {
+	// This will not panic given the guard in newWrappedBody.
+	n, err := wb.body.(io.Writer).Write(p)
+	if err != nil {
+		wb.span.RecordError(err)
+		wb.span.SetStatus(codes.Error, err.Error())
+	}
+	return n, err
+}
+
+func (wb *wrappedBody) Read(b []byte) (int, error) {
+	n, err := wb.body.Read(b)
+
+	switch err {
+	case nil:
+		// nothing to do here but fall through to the return
+	case io.EOF:
+		wb.span.End()
+	default:
+		wb.span.RecordError(err)
+		wb.span.SetStatus(codes.Error, err.Error())
+	}
+	return n, err
+}
+
+func (wb *wrappedBody) Close() error {
+	wb.span.End()
+	return wb.body.Close()
+}

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp/version.go

@@ -0,0 +1,26 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package otelhttp
+
+// Version is the current release version of the otelhttp instrumentation.
+func Version() string {
+	return "0.29.0"
+	// This string is updated by the pre_release.sh script during release
+}
+
+// SemVersion is the semantic version to be supplied to tracer/meter creation.
+func SemVersion() string {
+	return "semver:" + Version()
+}

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp/wrap.go

@@ -0,0 +1,96 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package otelhttp
+
+import (
+	"context"
+	"io"
+	"net/http"
+
+	"go.opentelemetry.io/otel/propagation"
+)
+
+var _ io.ReadCloser = &bodyWrapper{}
+
+// bodyWrapper wraps a http.Request.Body (an io.ReadCloser) to track the number
+// of bytes read and the last error
+type bodyWrapper struct {
+	io.ReadCloser
+	record func(n int64) // must not be nil
+
+	read int64
+	err  error
+}
+
+func (w *bodyWrapper) Read(b []byte) (int, error) {
+	n, err := w.ReadCloser.Read(b)
+	n1 := int64(n)
+	w.read += n1
+	w.err = err
+	w.record(n1)
+	return n, err
+}
+
+func (w *bodyWrapper) Close() error {
+	return w.ReadCloser.Close()
+}
+
+var _ http.ResponseWriter = &respWriterWrapper{}
+
+// respWriterWrapper wraps a http.ResponseWriter in order to track the number of
+// bytes written, the last error, and to catch the returned statusCode
+// TODO: The wrapped http.ResponseWriter doesn't implement any of the optional
+// types (http.Hijacker, http.Pusher, http.CloseNotifier, http.Flusher, etc)
+// that may be useful when using it in real life situations.
+type respWriterWrapper struct {
+	http.ResponseWriter
+	record func(n int64) // must not be nil
+
+	// used to inject the header
+	ctx context.Context
+
+	props propagation.TextMapPropagator
+
+	written     int64
+	statusCode  int
+	err         error
+	wroteHeader bool
+}
+
+func (w *respWriterWrapper) Header() http.Header {
+	return w.ResponseWriter.Header()
+}
+
+func (w *respWriterWrapper) Write(p []byte) (int, error) {
+	if !w.wroteHeader {
+		w.WriteHeader(http.StatusOK)
+	}
+	n, err := w.ResponseWriter.Write(p)
+	n1 := int64(n)
+	w.record(n1)
+	w.written += n1
+	w.err = err
+	return n, err
+}
+
+func (w *respWriterWrapper) WriteHeader(statusCode int) {
+	if w.wroteHeader {
+		return
+	}
+	w.wroteHeader = true
+	w.statusCode = statusCode
+	w.props.Inject(w.ctx, propagation.HeaderCarrier(w.Header()))
+	w.ResponseWriter.WriteHeader(statusCode)
+}

vendor/go.opentelemetry.io/otel/.gitattributes

@@ -0,0 +1,3 @@
+* text=auto eol=lf
+*.{cmd,[cC][mM][dD]} text eol=crlf
+*.{bat,[bB][aA][tT]} text eol=crlf

vendor/go.opentelemetry.io/otel/.gitignore

@@ -0,0 +1,21 @@
+.DS_Store
+Thumbs.db
+
+.tools/
+.idea/
+.vscode/
+*.iml
+*.so
+coverage.*
+
+gen/
+
+/example/fib/fib
+/example/jaeger/jaeger
+/example/namedtracer/namedtracer
+/example/opencensus/opencensus
+/example/passthrough/passthrough
+/example/prometheus/prometheus
+/example/prom-collector/prom-collector
+/example/zipkin/zipkin
+/example/otel-collector/otel-collector

vendor/go.opentelemetry.io/otel/.gitmodules

@@ -0,0 +1,3 @@
+[submodule "opentelemetry-proto"]
+	path = exporters/otlp/internal/opentelemetry-proto
+	url = https://github.com/open-telemetry/opentelemetry-proto

vendor/go.opentelemetry.io/otel/.golangci.yml

@@ -0,0 +1,47 @@
+# See https://github.com/golangci/golangci-lint#config-file
+run:
+  issues-exit-code: 1 #Default
+  tests: true #Default
+
+linters:
+  # Disable everything by default so upgrades to not include new "default
+  # enabled" linters.
+  disable-all: true
+  # Specifically enable linters we want to use.
+  enable:
+    - deadcode
+    - errcheck
+    - gofmt
+    - goimports
+    - gosimple
+    - govet
+    - ineffassign
+    - misspell
+    - revive
+    - staticcheck
+    - structcheck
+    - typecheck
+    - unused
+    - varcheck
+
+
+issues:
+  exclude-rules:
+    # helpers in tests often (rightfully) pass a *testing.T as their first argument
+    - path: _test\.go
+      text: "context.Context should be the first parameter of a function"
+      linters:
+        - revive
+    # Yes, they are, but it's okay in a test
+    - path: _test\.go
+      text: "exported func.*returns unexported type.*which can be annoying to use"
+      linters:
+        - revive
+
+linters-settings:
+  misspell:
+    locale: US
+    ignore-words:
+      - cancelled
+  goimports:
+    local-prefixes: go.opentelemetry.io

vendor/go.opentelemetry.io/otel/.markdown-link.json

@@ -0,0 +1,16 @@
+{
+    "ignorePatterns": [
+        {
+            "pattern": "^http(s)?://localhost"
+        }
+    ],
+    "replacementPatterns": [
+        {
+            "pattern": "^/registry",
+            "replacement": "https://opentelemetry.io/registry"
+        }
+    ],
+    "retryOn429": true,
+    "retryCount": 5,
+    "fallbackRetryDelay": "30s"
+}

vendor/go.opentelemetry.io/otel/.markdownlint.yaml

@@ -0,0 +1,29 @@
+# Default state for all rules
+default: true
+
+# ul-style
+MD004: false
+
+# hard-tabs
+MD010: false
+
+# line-length
+MD013: false
+
+# no-duplicate-header
+MD024:
+  siblings_only: true
+
+#single-title
+MD025: false
+
+# ol-prefix
+MD029:
+  style: ordered
+
+# no-inline-html
+MD033: false
+
+# fenced-code-language
+MD040: false
+

vendor/go.opentelemetry.io/otel/CODEOWNERS

@@ -0,0 +1,17 @@
+#####################################################
+#
+# List of approvers for this repository
+#
+#####################################################
+#
+# Learn about membership in OpenTelemetry community:
+#  https://github.com/open-telemetry/community/blob/main/community-membership.md
+#
+#
+# Learn about CODEOWNERS file format:
+#  https://help.github.com/en/articles/about-code-owners
+#
+
+* @jmacd @MrAlias @Aneurysm9 @evantorrie @XSAM @dashpole @paivagustavo @MadVikingGod @pellared
+
+CODEOWNERS @MrAlias @Aneurysm9 @MadVikingGod

vendor/go.opentelemetry.io/otel/CONTRIBUTING.md

@@ -0,0 +1,521 @@
+# Contributing to opentelemetry-go
+
+The Go special interest group (SIG) meets regularly. See the
+OpenTelemetry
+[community](https://github.com/open-telemetry/community#golang-sdk)
+repo for information on this and other language SIGs.
+
+See the [public meeting
+notes](https://docs.google.com/document/d/1A63zSWX0x2CyCK_LoNhmQC4rqhLpYXJzXbEPDUQ2n6w/edit#heading=h.9tngw7jdwd6b)
+for a summary description of past meetings. To request edit access,
+join the meeting or get in touch on
+[Slack](https://cloud-native.slack.com/archives/C01NPAXACKT).
+
+## Development
+
+You can view and edit the source code by cloning this repository:
+
+```sh
+git clone https://github.com/open-telemetry/opentelemetry-go.git
+```
+
+Run `make test` to run the tests instead of `go test`.
+
+There are some generated files checked into the repo. To make sure
+that the generated files are up-to-date, run `make` (or `make
+precommit` - the `precommit` target is the default).
+
+The `precommit` target also fixes the formatting of the code and
+checks the status of the go module files.
+
+If after running `make precommit` the output of `git status` contains
+`nothing to commit, working tree clean` then it means that everything
+is up-to-date and properly formatted.
+
+## Pull Requests
+
+### How to Send Pull Requests
+
+Everyone is welcome to contribute code to `opentelemetry-go` via
+GitHub pull requests (PRs).
+
+To create a new PR, fork the project in GitHub and clone the upstream
+repo:
+
+```sh
+go get -d go.opentelemetry.io/otel
+```
+
+(This may print some warning about "build constraints exclude all Go
+files", just ignore it.)
+
+This will put the project in `${GOPATH}/src/go.opentelemetry.io/otel`. You
+can alternatively use `git` directly with:
+
+```sh
+git clone https://github.com/open-telemetry/opentelemetry-go
+```
+
+(Note that `git clone` is *not* using the `go.opentelemetry.io/otel` name -
+that name is a kind of a redirector to GitHub that `go get` can
+understand, but `git` does not.)
+
+This would put the project in the `opentelemetry-go` directory in
+current working directory.
+
+Enter the newly created directory and add your fork as a new remote:
+
+```sh
+git remote add <YOUR_FORK> git@github.com:<YOUR_GITHUB_USERNAME>/opentelemetry-go
+```
+
+Check out a new branch, make modifications, run linters and tests, update
+`CHANGELOG.md`, and push the branch to your fork:
+
+```sh
+git checkout -b <YOUR_BRANCH_NAME>
+# edit files
+# update changelog
+make precommit
+git add -p
+git commit
+git push <YOUR_FORK> <YOUR_BRANCH_NAME>
+```
+
+Open a pull request against the main `opentelemetry-go` repo. Be sure to add the pull
+request ID to the entry you added to `CHANGELOG.md`.
+
+### How to Receive Comments
+
+* If the PR is not ready for review, please put `[WIP]` in the title,
+  tag it as `work-in-progress`, or mark it as
+  [`draft`](https://github.blog/2019-02-14-introducing-draft-pull-requests/).
+* Make sure CLA is signed and CI is clear.
+
+### How to Get PRs Merged
+
+A PR is considered to be **ready to merge** when:
+
+* It has received two approvals from Collaborators/Maintainers (at
+  different companies). This is not enforced through technical means
+  and a PR may be **ready to merge** with a single approval if the change
+  and its approach have been discussed and consensus reached.
+* Feedback has been addressed.
+* Any substantive changes to your PR will require that you clear any prior
+  Approval reviews, this includes changes resulting from other feedback. Unless
+  the approver explicitly stated that their approval will persist across
+  changes it should be assumed that the PR needs their review again. Other
+  project members (e.g. approvers, maintainers) can help with this if there are
+  any questions or if you forget to clear reviews.
+* It has been open for review for at least one working day. This gives
+  people reasonable time to review.
+* Trivial changes (typo, cosmetic, doc, etc.) do not have to wait for
+  one day and may be merged with a single Maintainer's approval.
+* `CHANGELOG.md` has been updated to reflect what has been
+  added, changed, removed, or fixed.
+* `README.md` has been updated if necessary.
+* Urgent fix can take exception as long as it has been actively
+  communicated.
+
+Any Maintainer can merge the PR once it is **ready to merge**.
+
+## Design Choices
+
+As with other OpenTelemetry clients, opentelemetry-go follows the
+[opentelemetry-specification](https://github.com/open-telemetry/opentelemetry-specification).
+
+It's especially valuable to read through the [library
+guidelines](https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/library-guidelines.md).
+
+### Focus on Capabilities, Not Structure Compliance
+
+OpenTelemetry is an evolving specification, one where the desires and
+use cases are clear, but the method to satisfy those uses cases are
+not.
+
+As such, Contributions should provide functionality and behavior that
+conforms to the specification, but the interface and structure is
+flexible.
+
+It is preferable to have contributions follow the idioms of the
+language rather than conform to specific API names or argument
+patterns in the spec.
+
+For a deeper discussion, see
+[this](https://github.com/open-telemetry/opentelemetry-specification/issues/165).
+
+## Documentation
+
+Each non-example Go Module should have its own `README.md` containing:
+
+- A pkg.go.dev badge which can be generated [here](https://pkg.go.dev/badge/).
+- Brief description.
+- Installation instructions (and requirements if applicable).
+- Hyperlink to an example. Depending on the component the example can be:
+  - An `example_test.go` like [here](exporters/stdout/stdouttrace/example_test.go).
+  - A sample Go application with its own `README.md`, like [here](example/zipkin).
+- Additional documentation sections such us:
+  - Configuration,
+  - Contributing,
+  - References.
+
+[Here](exporters/jaeger/README.md) is an example of a concise `README.md`.
+
+Moreover, it should be possible to navigate to any `README.md` from the
+root `README.md`.
+
+## Style Guide
+
+One of the primary goals of this project is that it is actually used by
+developers. With this goal in mind the project strives to build
+user-friendly and idiomatic Go code adhering to the Go community's best
+practices.
+
+For a non-comprehensive but foundational overview of these best practices
+the [Effective Go](https://golang.org/doc/effective_go.html) documentation
+is an excellent starting place.
+
+As a convenience for developers building this project the `make precommit`
+will format, lint, validate, and in some cases fix the changes you plan to
+submit. This check will need to pass for your changes to be able to be
+merged.
+
+In addition to idiomatic Go, the project has adopted certain standards for
+implementations of common patterns. These standards should be followed as a
+default, and if they are not followed documentation needs to be included as
+to the reasons why.
+
+### Configuration
+
+When creating an instantiation function for a complex `type T struct`, it is
+useful to allow variable number of options to be applied. However, the strong
+type system of Go restricts the function design options. There are a few ways
+to solve this problem, but we have landed on the following design.
+
+#### `config`
+
+Configuration should be held in a `struct` named `config`, or prefixed with
+specific type name this Configuration applies to if there are multiple
+`config` in the package. This type must contain configuration options.
+
+```go
+// config contains configuration options for a thing.
+type config struct {
+	// options ...
+}
+```
+
+In general the `config` type will not need to be used externally to the
+package and should be unexported. If, however, it is expected that the user
+will likely want to build custom options for the configuration, the `config`
+should be exported. Please, include in the documentation for the `config`
+how the user can extend the configuration.
+
+It is important that internal `config` are not shared across package boundaries.
+Meaning a `config` from one package should not be directly used by another. The
+one exception is the API packages.  The configs from the base API, eg.
+`go.opentelemetry.io/otel/trace.TracerConfig` and
+`go.opentelemetry.io/otel/metric.InstrumentConfig`, are intended to be consumed
+by the SDK therefor it is expected that these are exported.
+
+When a config is exported we want to maintain forward and backward
+compatibility, to achieve this no fields should be exported but should
+instead be accessed by methods.
+
+Optionally, it is common to include a `newConfig` function (with the same
+naming scheme). This function wraps any defaults setting and looping over
+all options to create a configured `config`.
+
+```go
+// newConfig returns an appropriately configured config.
+func newConfig(options ...Option) config {
+	// Set default values for config.
+	config := config{/* […] */}
+	for _, option := range options {
+		config = option.apply(config)
+	}
+	// Preform any validation here.
+	return config
+}
+```
+
+If validation of the `config` options is also preformed this can return an
+error as well that is expected to be handled by the instantiation function
+or propagated to the user.
+
+Given the design goal of not having the user need to work with the `config`,
+the `newConfig` function should also be unexported.
+
+#### `Option`
+
+To set the value of the options a `config` contains, a corresponding
+`Option` interface type should be used.
+
+```go
+type Option interface {
+	apply(config) config
+}
+```
+
+Having `apply` unexported makes sure that it will not be used externally.
+Moreover, the interface becomes sealed so the user cannot easily implement
+the interface on its own.
+
+The `apply` method should return a modified version of the passed config.
+This approach, instead of passing a pointer, is used to prevent the config from being allocated to the heap.
+
+The name of the interface should be prefixed in the same way the
+corresponding `config` is (if at all).
+
+#### Options
+
+All user configurable options for a `config` must have a related unexported
+implementation of the `Option` interface and an exported configuration
+function that wraps this implementation.
+
+The wrapping function name should be prefixed with `With*` (or in the
+special case of a boolean options `Without*`) and should have the following
+function signature.
+
+```go
+func With*(…) Option { … }
+```
+
+##### `bool` Options
+
+```go
+type defaultFalseOption bool
+
+func (o defaultFalseOption) apply(c config) config {
+	c.Bool = bool(o)
+    return c
+}
+
+// WithOption sets a T to have an option included.
+func WithOption() Option {
+	return defaultFalseOption(true)
+}
+```
+
+```go
+type defaultTrueOption bool
+
+func (o defaultTrueOption) apply(c config) config {
+	c.Bool = bool(o)
+    return c
+}
+
+// WithoutOption sets a T to have Bool option excluded.
+func WithoutOption() Option {
+	return defaultTrueOption(false)
+}
+```
+
+##### Declared Type Options
+
+```go
+type myTypeOption struct {
+	MyType MyType
+}
+
+func (o myTypeOption) apply(c config) config {
+	c.MyType = o.MyType
+    return c
+}
+
+// WithMyType sets T to have include MyType.
+func WithMyType(t MyType) Option {
+	return myTypeOption{t}
+}
+```
+
+##### Functional Options
+
+```go
+type optionFunc func(config) config
+
+func (fn optionFunc) apply(c config) config {
+	return fn(c)
+}
+
+// WithMyType sets t as MyType.
+func WithMyType(t MyType) Option {
+	return optionFunc(func(c config) config {
+		c.MyType = t
+        return c
+	})
+}
+```
+
+#### Instantiation
+
+Using this configuration pattern to configure instantiation with a `NewT`
+function.
+
+```go
+func NewT(options ...Option) T {…}
+```
+
+Any required parameters can be declared before the variadic `options`.
+
+#### Dealing with Overlap
+
+Sometimes there are multiple complex `struct` that share common
+configuration and also have distinct configuration. To avoid repeated
+portions of `config`s, a common `config` can be used with the union of
+options being handled with the `Option` interface.
+
+For example.
+
+```go
+// config holds options for all animals.
+type config struct {
+	Weight      float64
+	Color       string
+	MaxAltitude float64
+}
+
+// DogOption apply Dog specific options.
+type DogOption interface {
+	applyDog(config) config
+}
+
+// BirdOption apply Bird specific options.
+type BirdOption interface {
+	applyBird(config) config
+}
+
+// Option apply options for all animals.
+type Option interface {
+	BirdOption
+	DogOption
+}
+
+type weightOption float64
+
+func (o weightOption) applyDog(c config) config {
+	c.Weight = float64(o)
+	return c
+}
+
+func (o weightOption) applyBird(c config) config {
+	c.Weight = float64(o)
+	return c
+}
+
+func WithWeight(w float64) Option { return weightOption(w) }
+
+type furColorOption string
+
+func (o furColorOption) applyDog(c config) config {
+	c.Color = string(o)
+	return c
+}
+
+func WithFurColor(c string) DogOption { return furColorOption(c) }
+
+type maxAltitudeOption float64
+
+func (o maxAltitudeOption) applyBird(c config) config {
+	c.MaxAltitude = float64(o)
+	return c
+}
+
+func WithMaxAltitude(a float64) BirdOption { return maxAltitudeOption(a) }
+
+func NewDog(name string, o ...DogOption) Dog    {…}
+func NewBird(name string, o ...BirdOption) Bird {…}
+```
+
+### Interfaces
+
+To allow other developers to better comprehend the code, it is important
+to ensure it is sufficiently documented. One simple measure that contributes
+to this aim is self-documenting by naming method parameters. Therefore,
+where appropriate, methods of every exported interface type should have
+their parameters appropriately named.
+
+#### Interface Stability
+
+All exported stable interfaces that include the following warning in their
+doumentation are allowed to be extended with additional methods.
+
+> Warning: methods may be added to this interface in minor releases.
+
+Otherwise, stable interfaces MUST NOT be modified.
+
+If new functionality is needed for an interface that cannot be changed it MUST
+be added by including an additional interface. That added interface can be a
+simple interface for the specific functionality that you want to add or it can
+be a super-set of the original interface. For example, if you wanted to a
+`Close` method to the `Exporter` interface:
+
+```go
+type Exporter interface {
+	Export()
+}
+```
+
+A new interface, `Closer`, can be added:
+
+```go
+type Closer interface {
+	Close()
+}
+```
+
+Code that is passed the `Exporter` interface can now check to see if the passed
+value also satisfies the new interface. E.g.
+
+```go
+func caller(e Exporter) {
+	/* ... */
+	if c, ok := e.(Closer); ok {
+		c.Close()
+	}
+	/* ... */
+}
+```
+
+Alternatively, a new type that is the super-set of an `Exporter` can be created.
+
+```go
+type ClosingExporter struct {
+	Exporter
+	Close()
+}
+```
+
+This new type can be used similar to the simple interface above in that a
+passed `Exporter` type can be asserted to satisfy the `ClosingExporter` type
+and the `Close` method called.
+
+This super-set approach can be useful if there is explicit behavior that needs
+to be coupled with the original type and passed as a unified type to a new
+function, but, because of this coupling, it also limits the applicability of
+the added functionality. If there exist other interfaces where this
+functionality should be added, each one will need their own super-set
+interfaces and will duplicate the pattern. For this reason, the simple targeted
+interface that defines the specific functionality should be preferred.
+
+## Approvers and Maintainers
+
+Approvers:
+
+- [Evan Torrie](https://github.com/evantorrie), Verizon Media
+- [Josh MacDonald](https://github.com/jmacd), LightStep
+- [Sam Xie](https://github.com/XSAM), Cisco/AppDynamics
+- [David Ashpole](https://github.com/dashpole), Google
+- [Gustavo Silva Paiva](https://github.com/paivagustavo), LightStep
+- [Robert Pająk](https://github.com/pellared), Splunk
+
+Maintainers:
+
+- [Aaron Clawson](https://github.com/MadVikingGod), LightStep
+- [Anthony Mirabella](https://github.com/Aneurysm9), AWS
+- [Tyler Yahn](https://github.com/MrAlias), Splunk
+
+### Become an Approver or a Maintainer
+
+See the [community membership document in OpenTelemetry community
+repo](https://github.com/open-telemetry/community/blob/main/community-membership.md).

vendor/go.opentelemetry.io/otel/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
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+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
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+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
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+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
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+      with Licensor regarding such Contributions.
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+   6. Trademarks. This License does not grant permission to use the trade
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+
+   7. Disclaimer of Warranty. Unless required by applicable law or
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+      negligent acts) or agreed to in writing, shall any Contributor be
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vendor/go.opentelemetry.io/otel/Makefile

@@ -0,0 +1,212 @@
+# Copyright The OpenTelemetry Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+TOOLS_MOD_DIR := ./internal/tools
+
+ALL_DOCS := $(shell find . -name '*.md' -type f | sort)
+ALL_GO_MOD_DIRS := $(shell find . -type f -name 'go.mod' -exec dirname {} \; | sort)
+OTEL_GO_MOD_DIRS := $(filter-out $(TOOLS_MOD_DIR), $(ALL_GO_MOD_DIRS))
+ALL_COVERAGE_MOD_DIRS := $(shell find . -type f -name 'go.mod' -exec dirname {} \; | egrep -v '^./example|^$(TOOLS_MOD_DIR)' | sort)
+
+GO = go
+TIMEOUT = 60
+
+.DEFAULT_GOAL := precommit
+
+.PHONY: precommit ci
+precommit: license-check misspell go-mod-tidy golangci-lint-fix test-default
+ci: dependabot-check license-check lint vanity-import-check build test-default check-clean-work-tree test-coverage
+
+# Tools
+
+TOOLS = $(CURDIR)/.tools
+
+$(TOOLS):
+	@mkdir -p $@
+$(TOOLS)/%: | $(TOOLS)
+	cd $(TOOLS_MOD_DIR) && \
+	$(GO) build -o $@ $(PACKAGE)
+
+MULTIMOD = $(TOOLS)/multimod
+$(TOOLS)/multimod: PACKAGE=go.opentelemetry.io/build-tools/multimod
+
+SEMCONVGEN = $(TOOLS)/semconvgen
+$(TOOLS)/semconvgen: PACKAGE=go.opentelemetry.io/build-tools/semconvgen
+
+CROSSLINK = $(TOOLS)/crosslink
+$(TOOLS)/crosslink: PACKAGE=go.opentelemetry.io/otel/$(TOOLS_MOD_DIR)/crosslink
+
+GOLANGCI_LINT = $(TOOLS)/golangci-lint
+$(TOOLS)/golangci-lint: PACKAGE=github.com/golangci/golangci-lint/cmd/golangci-lint
+
+MISSPELL = $(TOOLS)/misspell
+$(TOOLS)/misspell: PACKAGE=github.com/client9/misspell/cmd/misspell
+
+GOCOVMERGE = $(TOOLS)/gocovmerge
+$(TOOLS)/gocovmerge: PACKAGE=github.com/wadey/gocovmerge
+
+STRINGER = $(TOOLS)/stringer
+$(TOOLS)/stringer: PACKAGE=golang.org/x/tools/cmd/stringer
+
+PORTO = $(TOOLS)/porto
+$(TOOLS)/porto: PACKAGE=github.com/jcchavezs/porto/cmd/porto
+
+GOJQ = $(TOOLS)/gojq
+$(TOOLS)/gojq: PACKAGE=github.com/itchyny/gojq/cmd/gojq
+
+.PHONY: tools
+tools: $(CROSSLINK) $(GOLANGCI_LINT) $(MISSPELL) $(GOCOVMERGE) $(STRINGER) $(PORTO) $(GOJQ) $(SEMCONVGEN) $(MULTIMOD)
+
+# Build
+
+.PHONY: generate build
+
+generate: $(OTEL_GO_MOD_DIRS:%=generate/%)
+generate/%: DIR=$*
+generate/%: | $(STRINGER) $(PORTO)
+	@echo "$(GO) generate $(DIR)/..." \
+		&& cd $(DIR) \
+		&& PATH="$(TOOLS):$${PATH}" $(GO) generate ./... && $(PORTO) -w .
+
+build: generate $(OTEL_GO_MOD_DIRS:%=build/%) $(OTEL_GO_MOD_DIRS:%=build-tests/%)
+build/%: DIR=$*
+build/%:
+	@echo "$(GO) build $(DIR)/..." \
+		&& cd $(DIR) \
+		&& $(GO) build ./...
+
+build-tests/%: DIR=$*
+build-tests/%:
+	@echo "$(GO) build tests $(DIR)/..." \
+		&& cd $(DIR) \
+		&& $(GO) list ./... \
+		| grep -v third_party \
+		| xargs $(GO) test -vet=off -run xxxxxMatchNothingxxxxx >/dev/null
+
+# Tests
+
+TEST_TARGETS := test-default test-bench test-short test-verbose test-race
+.PHONY: $(TEST_TARGETS) test
+test-default test-race: ARGS=-race
+test-bench:   ARGS=-run=xxxxxMatchNothingxxxxx -test.benchtime=1ms -bench=.
+test-short:   ARGS=-short
+test-verbose: ARGS=-v -race
+$(TEST_TARGETS): test
+test: $(OTEL_GO_MOD_DIRS:%=test/%)
+test/%: DIR=$*
+test/%:
+	@echo "$(GO) test -timeout $(TIMEOUT)s $(ARGS) $(DIR)/..." \
+		&& cd $(DIR) \
+		&& $(GO) list ./... \
+		| grep -v third_party \
+		| xargs $(GO) test -timeout $(TIMEOUT)s $(ARGS)
+
+COVERAGE_MODE    = atomic
+COVERAGE_PROFILE = coverage.out
+.PHONY: test-coverage
+test-coverage: | $(GOCOVMERGE)
+	@set -e; \
+	printf "" > coverage.txt; \
+	for dir in $(ALL_COVERAGE_MOD_DIRS); do \
+	  echo "$(GO) test -coverpkg=go.opentelemetry.io/otel/... -covermode=$(COVERAGE_MODE) -coverprofile="$(COVERAGE_PROFILE)" $${dir}/..."; \
+	  (cd "$${dir}" && \
+	    $(GO) list ./... \
+	    | grep -v third_party \
+	    | xargs $(GO) test -coverpkg=./... -covermode=$(COVERAGE_MODE) -coverprofile="$(COVERAGE_PROFILE)" && \
+	  $(GO) tool cover -html=coverage.out -o coverage.html); \
+	done; \
+	$(GOCOVMERGE) $$(find . -name coverage.out) > coverage.txt
+
+.PHONY: golangci-lint golangci-lint-fix
+golangci-lint-fix: ARGS=--fix
+golangci-lint-fix: golangci-lint
+golangci-lint: $(OTEL_GO_MOD_DIRS:%=golangci-lint/%)
+golangci-lint/%: DIR=$*
+golangci-lint/%: | $(GOLANGCI_LINT)
+	@echo 'golangci-lint $(if $(ARGS),$(ARGS) ,)$(DIR)' \
+		&& cd $(DIR) \
+		&& $(GOLANGCI_LINT) run --allow-serial-runners $(ARGS)
+
+.PHONY: crosslink
+crosslink: | $(CROSSLINK)
+	@echo "cross-linking all go modules" \
+		&& $(CROSSLINK)
+
+.PHONY: go-mod-tidy
+go-mod-tidy: $(ALL_GO_MOD_DIRS:%=go-mod-tidy/%)
+go-mod-tidy/%: DIR=$*
+go-mod-tidy/%: | crosslink
+	@echo "$(GO) mod tidy in $(DIR)" \
+		&& cd $(DIR) \
+		&& $(GO) mod tidy
+
+.PHONY: lint-modules
+lint-modules: go-mod-tidy
+
+.PHONY: lint
+lint: misspell lint-modules golangci-lint
+
+.PHONY: vanity-import-check
+vanity-import-check: | $(PORTO)
+	@$(PORTO) --include-internal -l .
+
+.PHONY: misspell
+misspell: | $(MISSPELL)
+	@$(MISSPELL) -w $(ALL_DOCS)
+
+.PHONY: license-check
+license-check:
+	@licRes=$$(for f in $$(find . -type f \( -iname '*.go' -o -iname '*.sh' \) ! -path '**/third_party/*') ; do \
+	           awk '/Copyright The OpenTelemetry Authors|generated|GENERATED/ && NR<=3 { found=1; next } END { if (!found) print FILENAME }' $$f; \
+	   done); \
+	   if [ -n "$${licRes}" ]; then \
+	           echo "license header checking failed:"; echo "$${licRes}"; \
+	           exit 1; \
+	   fi
+
+DEPENDABOT_PATH=./.github/dependabot.yml
+.PHONY: dependabot-check
+dependabot-check:
+	@result=$$( \
+		for f in $$( find . -type f -name go.mod -exec dirname {} \; | sed 's/^.//' ); \
+			do grep -q "directory: \+$$f" $(DEPENDABOT_PATH) \
+			|| echo "$$f"; \
+		done; \
+	); \
+	if [ -n "$$result" ]; then \
+		echo "missing dependabot entry:"; echo "$$result"; \
+		echo "new modules need to be added to the $(DEPENDABOT_PATH) file"; \
+		exit 1; \
+	fi
+
+.PHONY: check-clean-work-tree
+check-clean-work-tree:
+	@if ! git diff --quiet; then \
+	  echo; \
+	  echo 'Working tree is not clean, did you forget to run "make precommit"?'; \
+	  echo; \
+	  git status; \
+	  exit 1; \
+	fi
+
+.PHONY: prerelease
+prerelease: | $(MULTIMOD)
+	@[ "${MODSET}" ] || ( echo ">> env var MODSET is not set"; exit 1 )
+	$(MULTIMOD) verify && $(MULTIMOD) prerelease -m ${MODSET}
+
+COMMIT ?= "HEAD"
+.PHONY: add-tags
+add-tags: | $(MULTIMOD)
+	@[ "${MODSET}" ] || ( echo ">> env var MODSET is not set"; exit 1 )
+	$(MULTIMOD) verify && $(MULTIMOD) tag -m ${MODSET} -c ${COMMIT}

vendor/go.opentelemetry.io/otel/README.md

@@ -0,0 +1,102 @@
+# OpenTelemetry-Go
+
+[![CI](https://github.com/open-telemetry/opentelemetry-go/workflows/ci/badge.svg)](https://github.com/open-telemetry/opentelemetry-go/actions?query=workflow%3Aci+branch%3Amain)
+[![codecov.io](https://codecov.io/gh/open-telemetry/opentelemetry-go/coverage.svg?branch=main)](https://app.codecov.io/gh/open-telemetry/opentelemetry-go?branch=main)
+[![PkgGoDev](https://pkg.go.dev/badge/go.opentelemetry.io/otel)](https://pkg.go.dev/go.opentelemetry.io/otel)
+[![Go Report Card](https://goreportcard.com/badge/go.opentelemetry.io/otel)](https://goreportcard.com/report/go.opentelemetry.io/otel)
+[![Slack](https://img.shields.io/badge/slack-@cncf/otel--go-brightgreen.svg?logo=slack)](https://cloud-native.slack.com/archives/C01NPAXACKT)
+
+OpenTelemetry-Go is the [Go](https://golang.org/) implementation of [OpenTelemetry](https://opentelemetry.io/).
+It provides a set of APIs to directly measure performance and behavior of your software and send this data to observability platforms.
+
+## Project Status
+
+| Signal  | Status     | Project |
+| ------- | ---------- | ------- |
+| Traces  | Stable     | N/A     |
+| Metrics | Alpha      | N/A     |
+| Logs    | Frozen [1] | N/A     |
+
+- [1]: The Logs signal development is halted for this project while we develop both Traces and Metrics.
+   No Logs Pull Requests are currently being accepted.
+
+Progress and status specific to this repository is tracked in our local
+[project boards](https://github.com/open-telemetry/opentelemetry-go/projects)
+and
+[milestones](https://github.com/open-telemetry/opentelemetry-go/milestones).
+
+Project versioning information and stability guarantees can be found in the
+[versioning documentation](./VERSIONING.md).
+
+### Compatibility
+
+OpenTelemetry-Go attempts to track the current supported versions of the
+[Go language](https://golang.org/doc/devel/release#policy). The release
+schedule after a new minor version of go is as follows:
+
+- The first release or one month, which ever is sooner, will add build steps for the new go version.
+- The first release after three months will remove support for the oldest go version.
+
+This project is tested on the following systems.
+
+| OS      | Go Version | Architecture |
+| ------- | ---------- | ------------ |
+| Ubuntu  | 1.17       | amd64        |
+| Ubuntu  | 1.16       | amd64        |
+| Ubuntu  | 1.17       | 386          |
+| Ubuntu  | 1.16       | 386          |
+| MacOS   | 1.17       | amd64        |
+| MacOS   | 1.16       | amd64        |
+| Windows | 1.17       | amd64        |
+| Windows | 1.16       | amd64        |
+| Windows | 1.17       | 386          |
+| Windows | 1.16       | 386          |
+
+While this project should work for other systems, no compatibility guarantees
+are made for those systems currently.
+
+## Getting Started
+
+You can find a getting started guide on [opentelemetry.io](https://opentelemetry.io/docs/go/getting-started/).
+
+OpenTelemetry's goal is to provide a single set of APIs to capture distributed
+traces and metrics from your application and send them to an observability
+platform. This project allows you to do just that for applications written in
+Go. There are two steps to this process: instrument your application, and
+configure an exporter.
+
+### Instrumentation
+
+To start capturing distributed traces and metric events from your application
+it first needs to be instrumented. The easiest way to do this is by using an
+instrumentation library for your code. Be sure to check out [the officially
+supported instrumentation
+libraries](https://github.com/open-telemetry/opentelemetry-go-contrib/tree/main/instrumentation).
+
+If you need to extend the telemetry an instrumentation library provides or want
+to build your own instrumentation for your application directly you will need
+to use the
+[go.opentelemetry.io/otel/api](https://pkg.go.dev/go.opentelemetry.io/otel/api)
+package. The included [examples](./example/) are a good way to see some
+practical uses of this process.
+
+### Export
+
+Now that your application is instrumented to collect telemetry, it needs an
+export pipeline to send that telemetry to an observability platform.
+
+All officially supported exporters for the OpenTelemetry project are contained in the [exporters directory](./exporters).
+
+| Exporter                              | Metrics | Traces |
+| :-----------------------------------: | :-----: | :----: |
+| [Jaeger](./exporters/jaeger/)         |         | ✓      |
+| [OTLP](./exporters/otlp/)             | ✓       | ✓      |
+| [Prometheus](./exporters/prometheus/) | ✓       |        |
+| [stdout](./exporters/stdout/)         | ✓       | ✓      |
+| [Zipkin](./exporters/zipkin/)         |         | ✓      |
+
+Additionally, OpenTelemetry community supported exporters can be found in the [contrib repository](https://github.com/open-telemetry/opentelemetry-go-contrib/tree/main/exporters).
+
+## Contributing
+
+See the [contributing documentation](CONTRIBUTING.md).

vendor/go.opentelemetry.io/otel/RELEASING.md

@@ -0,0 +1,132 @@
+# Release Process
+
+## Semantic Convention Generation
+
+If a new version of the OpenTelemetry Specification has been released it will be necessary to generate a new
+semantic convention package from the YAML definitions in the specification repository. There is a `semconvgen` utility
+installed by `make tools` that can be used to generate the a package with the name matching the specification
+version number under the `semconv` package. This will ideally be done soon after the specification release is
+tagged. Make sure that the specification repo contains a checkout of the the latest tagged release so that the
+generated files match the released semantic conventions.
+
+There are currently two categories of semantic conventions that must be generated, `resource` and `trace`.
+
+```
+.tools/semconvgen -i /path/to/specification/repo/semantic_conventions/resource -t semconv/template.j2
+.tools/semconvgen -i /path/to/specification/repo/semantic_conventions/trace -t semconv/template.j2
+```
+
+Using default values for all options other than `input` will result in using the `template.j2` template to
+generate `resource.go` and `trace.go` in `/path/to/otelgo/repo/semconv/<version>`.
+
+There are several ancillary files that are not generated and should be copied into the new package from the
+prior package, with updates made as appropriate to canonical import path statements and constant values.
+These files include:
+
+* doc.go
+* exception.go
+* http(_test)?.go
+* schema.go
+
+Uses of the previous schema version in this repository should be updated to use the newly generated version.
+No tooling for this exists at present, so use find/replace in your editor of choice or craft a `grep | sed`
+pipeline if you like living on the edge.
+
+## Pre-Release
+
+First, decide which module sets will be released and update their versions
+in `versions.yaml`.  Commit this change to a new branch.
+
+Update go.mod for submodules to depend on the new release which will happen in the next step.
+
+1. Run the `prerelease` make target. It creates a branch
+    `prerelease_<module set>_<new tag>` that will contain all release changes.
+
+    ```
+    make prerelease MODSET=<module set>
+    ```
+
+2. Verify the changes.
+
+    ```
+    git diff ...prerelease_<module set>_<new tag>
+    ```
+
+    This should have changed the version for all modules to be `<new tag>`.
+    If these changes look correct, merge them into your pre-release branch:
+
+    ```go
+    git merge prerelease_<module set>_<new tag>
+    ```
+
+3. Update the [Changelog](./CHANGELOG.md).
+   - Make sure all relevant changes for this release are included and are in language that non-contributors to the project can understand.
+       To verify this, you can look directly at the commits since the `<last tag>`.
+
+       ```
+       git --no-pager log --pretty=oneline "<last tag>..HEAD"
+       ```
+
+   - Move all the `Unreleased` changes into a new section following the title scheme (`[<new tag>] - <date of release>`).
+   - Update all the appropriate links at the bottom.
+
+4. Push the changes to upstream and create a Pull Request on GitHub.
+    Be sure to include the curated changes from the [Changelog](./CHANGELOG.md) in the description.
+
+## Tag
+
+Once the Pull Request with all the version changes has been approved and merged it is time to tag the merged commit.
+
+***IMPORTANT***: It is critical you use the same tag that you used in the Pre-Release step!
+Failure to do so will leave things in a broken state. As long as you do not
+change `versions.yaml` between pre-release and this step, things should be fine.
+
+***IMPORTANT***: [There is currently no way to remove an incorrectly tagged version of a Go module](https://github.com/golang/go/issues/34189).
+It is critical you make sure the version you push upstream is correct.
+[Failure to do so will lead to minor emergencies and tough to work around](https://github.com/open-telemetry/opentelemetry-go/issues/331).
+
+1. For each module set that will be released, run the `add-tags` make target
+    using the `<commit-hash>` of the commit on the main branch for the merged Pull Request.
+
+    ```
+    make add-tags MODSET=<module set> COMMIT=<commit hash>
+    ```
+
+    It should only be necessary to provide an explicit `COMMIT` value if the
+    current `HEAD` of your working directory is not the correct commit.
+
+2. Push tags to the upstream remote (not your fork: `github.com/open-telemetry/opentelemetry-go.git`).
+    Make sure you push all sub-modules as well.
+
+    ```
+    git push upstream <new tag>
+    git push upstream <submodules-path/new tag>
+    ...
+    ```
+
+## Release
+
+Finally create a Release for the new `<new tag>` on GitHub.
+The release body should include all the release notes from the Changelog for this release.
+
+## Verify Examples
+
+After releasing verify that examples build outside of the repository.
+
+```
+./verify_examples.sh
+```
+
+The script copies examples into a different directory removes any `replace` declarations in `go.mod` and builds them.
+This ensures they build with the published release, not the local copy.
+
+## Post-Release
+
+### Contrib Repository
+
+Once verified be sure to [make a release for the `contrib` repository](https://github.com/open-telemetry/opentelemetry-go-contrib/blob/main/RELEASING.md) that uses this release.
+
+### Website Documentation
+
+Update [the documentation](./website_docs) for [the OpenTelemetry website](https://opentelemetry.io/docs/go/).
+Importantly, bump any package versions referenced to be the latest one you just released and ensure all code examples still compile and are accurate.

vendor/go.opentelemetry.io/otel/VERSIONING.md

@@ -0,0 +1,224 @@
+# Versioning
+
+This document describes the versioning policy for this repository. This policy
+is designed so the following goals can be achieved.
+
+**Users are provided a codebase of value that is stable and secure.**
+
+## Policy
+
+* Versioning of this project will be idiomatic of a Go project using [Go
+  modules](https://github.com/golang/go/wiki/Modules).
+  * [Semantic import
+    versioning](https://github.com/golang/go/wiki/Modules#semantic-import-versioning)
+    will be used.
+    * Versions will comply with [semver
+      2.0](https://semver.org/spec/v2.0.0.html) with the following exceptions.
+      * New methods may be added to exported API interfaces. All exported
+        interfaces that fall within this exception will include the following
+        paragraph in their public documentation.
+
+        > Warning: methods may be added to this interface in minor releases.
+
+    * If a module is version `v2` or higher, the major version of the module
+      must be included as a `/vN` at the end of the module paths used in
+      `go.mod` files (e.g., `module go.opentelemetry.io/otel/v2`, `require
+      go.opentelemetry.io/otel/v2 v2.0.1`) and in the package import path
+      (e.g., `import "go.opentelemetry.io/otel/v2/trace"`). This includes the
+      paths used in `go get` commands (e.g., `go get
+      go.opentelemetry.io/otel/v2@v2.0.1`.  Note there is both a `/v2` and a
+      `@v2.0.1` in that example. One way to think about it is that the module
+      name now includes the `/v2`, so include `/v2` whenever you are using the
+      module name).
+    * If a module is version `v0` or `v1`, do not include the major version in
+      either the module path or the import path.
+  * Modules will be used to encapsulate signals and components.
+    * Experimental modules still under active development will be versioned at
+      `v0` to imply the stability guarantee defined by
+      [semver](https://semver.org/spec/v2.0.0.html#spec-item-4).
+
+      > Major version zero (0.y.z) is for initial development. Anything MAY
+      > change at any time. The public API SHOULD NOT be considered stable.
+
+    * Mature modules for which we guarantee a stable public API will be versioned
+      with a major version greater than `v0`.
+      * The decision to make a module stable will be made on a case-by-case
+        basis by the maintainers of this project.
+    * Experimental modules will start their versioning at `v0.0.0` and will
+      increment their minor version when backwards incompatible changes are
+      released and increment their patch version when backwards compatible
+      changes are released.
+    * All stable modules that use the same major version number will use the
+      same entire version number.
+      * Stable modules may be released with an incremented minor or patch
+        version even though that module has not been changed, but rather so
+        that it will remain at the same version as other stable modules that
+        did undergo change.
+      * When an experimental module becomes stable a new stable module version
+        will be released and will include this now stable module. The new
+        stable module version will be an increment of the minor version number
+        and will be applied to all existing stable modules as well as the newly
+        stable module being released.
+* Versioning of the associated [contrib
+  repository](https://github.com/open-telemetry/opentelemetry-go-contrib) of
+  this project will be idiomatic of a Go project using [Go
+  modules](https://github.com/golang/go/wiki/Modules).
+  * [Semantic import
+    versioning](https://github.com/golang/go/wiki/Modules#semantic-import-versioning)
+    will be used.
+    * Versions will comply with [semver 2.0](https://semver.org/spec/v2.0.0.html).
+    * If a module is version `v2` or higher, the
+      major version of the module must be included as a `/vN` at the end of the
+      module paths used in `go.mod` files (e.g., `module
+      go.opentelemetry.io/contrib/instrumentation/host/v2`, `require
+      go.opentelemetry.io/contrib/instrumentation/host/v2 v2.0.1`) and in the
+      package import path (e.g., `import
+      "go.opentelemetry.io/contrib/instrumentation/host/v2"`). This includes
+      the paths used in `go get` commands (e.g., `go get
+      go.opentelemetry.io/contrib/instrumentation/host/v2@v2.0.1`.  Note there
+      is both a `/v2` and a `@v2.0.1` in that example. One way to think about
+      it is that the module name now includes the `/v2`, so include `/v2`
+      whenever you are using the module name).
+    * If a module is version `v0` or `v1`, do not include the major version
+      in either the module path or the import path.
+  * In addition to public APIs, telemetry produced by stable instrumentation
+    will remain stable and backwards compatible. This is to avoid breaking
+    alerts and dashboard.
+  * Modules will be used to encapsulate instrumentation, detectors, exporters,
+    propagators, and any other independent sets of related components.
+    * Experimental modules still under active development will be versioned at
+      `v0` to imply the stability guarantee defined by
+      [semver](https://semver.org/spec/v2.0.0.html#spec-item-4).
+
+      > Major version zero (0.y.z) is for initial development. Anything MAY
+      > change at any time. The public API SHOULD NOT be considered stable.
+
+    * Mature modules for which we guarantee a stable public API and telemetry will
+      be versioned with a major version greater than `v0`.
+    * Experimental modules will start their versioning at `v0.0.0` and will
+      increment their minor version when backwards incompatible changes are
+      released and increment their patch version when backwards compatible
+      changes are released.
+    * Stable contrib modules cannot depend on experimental modules from this
+      project.
+    * All stable contrib modules of the same major version with this project
+      will use the same entire version as this project.
+      * Stable modules may be released with an incremented minor or patch
+        version even though that module's code has not been changed. Instead
+        the only change that will have been included is to have updated that
+        modules dependency on this project's stable APIs.
+      * When an experimental module in contrib becomes stable a new stable
+        module version will be released and will include this now stable
+        module. The new stable module version will be an increment of the minor
+        version number and will be applied to all existing stable contrib
+        modules, this project's modules, and the newly stable module being
+        released.
+  * Contrib modules will be kept up to date with this project's releases.
+    * Due to the dependency contrib modules will implicitly have on this
+      project's modules the release of stable contrib modules to match the
+      released version number will be staggered after this project's release.
+      There is no explicit time guarantee for how long after this projects
+      release the contrib release will be. Effort should be made to keep them
+      as close in time as possible.
+    * No additional stable release in this project can be made until the
+      contrib repository has a matching stable release.
+    * No release can be made in the contrib repository after this project's
+      stable release except for a stable release of the contrib repository.
+* GitHub releases will be made for all releases.
+* Go modules will be made available at Go package mirrors.
+
+## Example Versioning Lifecycle
+
+To better understand the implementation of the above policy the following
+example is provided. This project is simplified to include only the following
+modules and their versions:
+
+* `otel`: `v0.14.0`
+* `otel/trace`: `v0.14.0`
+* `otel/metric`: `v0.14.0`
+* `otel/baggage`: `v0.14.0`
+* `otel/sdk/trace`: `v0.14.0`
+* `otel/sdk/metric`: `v0.14.0`
+
+These modules have been developed to a point where the `otel/trace`,
+`otel/baggage`, and `otel/sdk/trace` modules have reached a point that they
+should be considered for a stable release. The `otel/metric` and
+`otel/sdk/metric` are still under active development and the `otel` module
+depends on both `otel/trace` and `otel/metric`.
+
+The `otel` package is refactored to remove its dependencies on `otel/metric` so
+it can be released as stable as well. With that done the following release
+candidates are made:
+
+* `otel`: `v1.0.0-RC1`
+* `otel/trace`: `v1.0.0-RC1`
+* `otel/baggage`: `v1.0.0-RC1`
+* `otel/sdk/trace`: `v1.0.0-RC1`
+
+The `otel/metric` and `otel/sdk/metric` modules remain at `v0.14.0`.
+
+A few minor issues are discovered in the `otel/trace` package. These issues are
+resolved with some minor, but backwards incompatible, changes and are released
+as a second release candidate:
+
+* `otel`: `v1.0.0-RC2`
+* `otel/trace`: `v1.0.0-RC2`
+* `otel/baggage`: `v1.0.0-RC2`
+* `otel/sdk/trace`: `v1.0.0-RC2`
+
+Notice that all module version numbers are incremented to adhere to our
+versioning policy.
+
+After these release candidates have been evaluated to satisfaction, they are
+released as version `v1.0.0`.
+
+* `otel`: `v1.0.0`
+* `otel/trace`: `v1.0.0`
+* `otel/baggage`: `v1.0.0`
+* `otel/sdk/trace`: `v1.0.0`
+
+Since both the `go` utility and the Go module system support [the semantic
+versioning definition of
+precedence](https://semver.org/spec/v2.0.0.html#spec-item-11), this release
+will correctly be interpreted as the successor to the previous release
+candidates.
+
+Active development of this project continues. The `otel/metric` module now has
+backwards incompatible changes to its API that need to be released and the
+`otel/baggage` module has a minor bug fix that needs to be released. The
+following release is made:
+
+* `otel`: `v1.0.1`
+* `otel/trace`: `v1.0.1`
+* `otel/metric`: `v0.15.0`
+* `otel/baggage`: `v1.0.1`
+* `otel/sdk/trace`: `v1.0.1`
+* `otel/sdk/metric`: `v0.15.0`
+
+Notice that, again, all stable module versions are incremented in unison and
+the `otel/sdk/metric` package, which depends on the `otel/metric` package, also
+bumped its version. This bump of the `otel/sdk/metric` package makes sense
+given their coupling, though it is not explicitly required by our versioning
+policy.
+
+As we progress, the `otel/metric` and `otel/sdk/metric` packages have reached a
+point where they should be evaluated for stability. The `otel` module is
+reintegrated with the `otel/metric` package and the following release is made:
+
+* `otel`: `v1.1.0-RC1`
+* `otel/trace`: `v1.1.0-RC1`
+* `otel/metric`: `v1.1.0-RC1`
+* `otel/baggage`: `v1.1.0-RC1`
+* `otel/sdk/trace`: `v1.1.0-RC1`
+* `otel/sdk/metric`: `v1.1.0-RC1`
+
+All the modules are evaluated and determined to a viable stable release. They
+are then released as version `v1.1.0` (the minor version is incremented to
+indicate the addition of new signal).
+
+* `otel`: `v1.1.0`
+* `otel/trace`: `v1.1.0`
+* `otel/metric`: `v1.1.0`
+* `otel/baggage`: `v1.1.0`
+* `otel/sdk/trace`: `v1.1.0`
+* `otel/sdk/metric`: `v1.1.0`

vendor/go.opentelemetry.io/otel/attribute/doc.go

@@ -0,0 +1,16 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package attribute provides key and value attributes.
+package attribute // import "go.opentelemetry.io/otel/attribute"

vendor/go.opentelemetry.io/otel/attribute/encoder.go

@@ -0,0 +1,150 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package attribute // import "go.opentelemetry.io/otel/attribute"
+
+import (
+	"bytes"
+	"sync"
+	"sync/atomic"
+)
+
+type (
+	// Encoder is a mechanism for serializing a label set into a
+	// specific string representation that supports caching, to
+	// avoid repeated serialization. An example could be an
+	// exporter encoding the label set into a wire representation.
+	Encoder interface {
+		// Encode returns the serialized encoding of the label
+		// set using its Iterator.  This result may be cached
+		// by a attribute.Set.
+		Encode(iterator Iterator) string
+
+		// ID returns a value that is unique for each class of
+		// label encoder.  Label encoders allocate these using
+		// `NewEncoderID`.
+		ID() EncoderID
+	}
+
+	// EncoderID is used to identify distinct Encoder
+	// implementations, for caching encoded results.
+	EncoderID struct {
+		value uint64
+	}
+
+	// defaultLabelEncoder uses a sync.Pool of buffers to reduce
+	// the number of allocations used in encoding labels.  This
+	// implementation encodes a comma-separated list of key=value,
+	// with '/'-escaping of '=', ',', and '\'.
+	defaultLabelEncoder struct {
+		// pool is a pool of labelset builders.  The buffers in this
+		// pool grow to a size that most label encodings will not
+		// allocate new memory.
+		pool sync.Pool // *bytes.Buffer
+	}
+)
+
+// escapeChar is used to ensure uniqueness of the label encoding where
+// keys or values contain either '=' or ','.  Since there is no parser
+// needed for this encoding and its only requirement is to be unique,
+// this choice is arbitrary.  Users will see these in some exporters
+// (e.g., stdout), so the backslash ('\') is used as a conventional choice.
+const escapeChar = '\\'
+
+var (
+	_ Encoder = &defaultLabelEncoder{}
+
+	// encoderIDCounter is for generating IDs for other label
+	// encoders.
+	encoderIDCounter uint64
+
+	defaultEncoderOnce     sync.Once
+	defaultEncoderID       = NewEncoderID()
+	defaultEncoderInstance *defaultLabelEncoder
+)
+
+// NewEncoderID returns a unique label encoder ID. It should be
+// called once per each type of label encoder. Preferably in init() or
+// in var definition.
+func NewEncoderID() EncoderID {
+	return EncoderID{value: atomic.AddUint64(&encoderIDCounter, 1)}
+}
+
+// DefaultEncoder returns a label encoder that encodes labels
+// in such a way that each escaped label's key is followed by an equal
+// sign and then by an escaped label's value. All key-value pairs are
+// separated by a comma.
+//
+// Escaping is done by prepending a backslash before either a
+// backslash, equal sign or a comma.
+func DefaultEncoder() Encoder {
+	defaultEncoderOnce.Do(func() {
+		defaultEncoderInstance = &defaultLabelEncoder{
+			pool: sync.Pool{
+				New: func() interface{} {
+					return &bytes.Buffer{}
+				},
+			},
+		}
+	})
+	return defaultEncoderInstance
+}
+
+// Encode is a part of an implementation of the LabelEncoder
+// interface.
+func (d *defaultLabelEncoder) Encode(iter Iterator) string {
+	buf := d.pool.Get().(*bytes.Buffer)
+	defer d.pool.Put(buf)
+	buf.Reset()
+
+	for iter.Next() {
+		i, keyValue := iter.IndexedLabel()
+		if i > 0 {
+			_, _ = buf.WriteRune(',')
+		}
+		copyAndEscape(buf, string(keyValue.Key))
+
+		_, _ = buf.WriteRune('=')
+
+		if keyValue.Value.Type() == STRING {
+			copyAndEscape(buf, keyValue.Value.AsString())
+		} else {
+			_, _ = buf.WriteString(keyValue.Value.Emit())
+		}
+	}
+	return buf.String()
+}
+
+// ID is a part of an implementation of the LabelEncoder interface.
+func (*defaultLabelEncoder) ID() EncoderID {
+	return defaultEncoderID
+}
+
+// copyAndEscape escapes `=`, `,` and its own escape character (`\`),
+// making the default encoding unique.
+func copyAndEscape(buf *bytes.Buffer, val string) {
+	for _, ch := range val {
+		switch ch {
+		case '=', ',', escapeChar:
+			buf.WriteRune(escapeChar)
+		}
+		buf.WriteRune(ch)
+	}
+}
+
+// Valid returns true if this encoder ID was allocated by
+// `NewEncoderID`.  Invalid encoder IDs will not be cached.
+func (id EncoderID) Valid() bool {
+	return id.value != 0
+}

vendor/go.opentelemetry.io/otel/attribute/iterator.go

@@ -0,0 +1,143 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package attribute // import "go.opentelemetry.io/otel/attribute"
+
+// Iterator allows iterating over the set of labels in order,
+// sorted by key.
+type Iterator struct {
+	storage *Set
+	idx     int
+}
+
+// MergeIterator supports iterating over two sets of labels while
+// eliminating duplicate values from the combined set.  The first
+// iterator value takes precedence.
+type MergeIterator struct {
+	one     oneIterator
+	two     oneIterator
+	current KeyValue
+}
+
+type oneIterator struct {
+	iter  Iterator
+	done  bool
+	label KeyValue
+}
+
+// Next moves the iterator to the next position. Returns false if there
+// are no more labels.
+func (i *Iterator) Next() bool {
+	i.idx++
+	return i.idx < i.Len()
+}
+
+// Label returns current KeyValue. Must be called only after Next returns
+// true.
+func (i *Iterator) Label() KeyValue {
+	kv, _ := i.storage.Get(i.idx)
+	return kv
+}
+
+// Attribute is a synonym for Label().
+func (i *Iterator) Attribute() KeyValue {
+	return i.Label()
+}
+
+// IndexedLabel returns current index and attribute. Must be called only
+// after Next returns true.
+func (i *Iterator) IndexedLabel() (int, KeyValue) {
+	return i.idx, i.Label()
+}
+
+// Len returns a number of labels in the iterator's `*Set`.
+func (i *Iterator) Len() int {
+	return i.storage.Len()
+}
+
+// ToSlice is a convenience function that creates a slice of labels
+// from the passed iterator. The iterator is set up to start from the
+// beginning before creating the slice.
+func (i *Iterator) ToSlice() []KeyValue {
+	l := i.Len()
+	if l == 0 {
+		return nil
+	}
+	i.idx = -1
+	slice := make([]KeyValue, 0, l)
+	for i.Next() {
+		slice = append(slice, i.Label())
+	}
+	return slice
+}
+
+// NewMergeIterator returns a MergeIterator for merging two label sets
+// Duplicates are resolved by taking the value from the first set.
+func NewMergeIterator(s1, s2 *Set) MergeIterator {
+	mi := MergeIterator{
+		one: makeOne(s1.Iter()),
+		two: makeOne(s2.Iter()),
+	}
+	return mi
+}
+
+func makeOne(iter Iterator) oneIterator {
+	oi := oneIterator{
+		iter: iter,
+	}
+	oi.advance()
+	return oi
+}
+
+func (oi *oneIterator) advance() {
+	if oi.done = !oi.iter.Next(); !oi.done {
+		oi.label = oi.iter.Label()
+	}
+}
+
+// Next returns true if there is another label available.
+func (m *MergeIterator) Next() bool {
+	if m.one.done && m.two.done {
+		return false
+	}
+	if m.one.done {
+		m.current = m.two.label
+		m.two.advance()
+		return true
+	}
+	if m.two.done {
+		m.current = m.one.label
+		m.one.advance()
+		return true
+	}
+	if m.one.label.Key == m.two.label.Key {
+		m.current = m.one.label // first iterator label value wins
+		m.one.advance()
+		m.two.advance()
+		return true
+	}
+	if m.one.label.Key < m.two.label.Key {
+		m.current = m.one.label
+		m.one.advance()
+		return true
+	}
+	m.current = m.two.label
+	m.two.advance()
+	return true
+}
+
+// Label returns the current value after Next() returns true.
+func (m *MergeIterator) Label() KeyValue {
+	return m.current
+}

vendor/go.opentelemetry.io/otel/attribute/key.go

@@ -0,0 +1,134 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package attribute // import "go.opentelemetry.io/otel/attribute"
+
+// Key represents the key part in key-value pairs. It's a string. The
+// allowed character set in the key depends on the use of the key.
+type Key string
+
+// Bool creates a KeyValue instance with a BOOL Value.
+//
+// If creating both a key and value at the same time, use the provided
+// convenience function instead -- Bool(name, value).
+func (k Key) Bool(v bool) KeyValue {
+	return KeyValue{
+		Key:   k,
+		Value: BoolValue(v),
+	}
+}
+
+// BoolSlice creates a KeyValue instance with a BOOLSLICE Value.
+//
+// If creating both a key and value at the same time, use the provided
+// convenience function instead -- BoolSlice(name, value).
+func (k Key) BoolSlice(v []bool) KeyValue {
+	return KeyValue{
+		Key:   k,
+		Value: BoolSliceValue(v),
+	}
+}
+
+// Int creates a KeyValue instance with an INT64 Value.
+//
+// If creating both a key and value at the same time, use the provided
+// convenience function instead -- Int(name, value).
+func (k Key) Int(v int) KeyValue {
+	return KeyValue{
+		Key:   k,
+		Value: IntValue(v),
+	}
+}
+
+// IntSlice creates a KeyValue instance with an INT64SLICE Value.
+//
+// If creating both a key and value at the same time, use the provided
+// convenience function instead -- IntSlice(name, value).
+func (k Key) IntSlice(v []int) KeyValue {
+	return KeyValue{
+		Key:   k,
+		Value: IntSliceValue(v),
+	}
+}
+
+// Int64 creates a KeyValue instance with an INT64 Value.
+//
+// If creating both a key and value at the same time, use the provided
+// convenience function instead -- Int64(name, value).
+func (k Key) Int64(v int64) KeyValue {
+	return KeyValue{
+		Key:   k,
+		Value: Int64Value(v),
+	}
+}
+
+// Int64Slice creates a KeyValue instance with an INT64SLICE Value.
+//
+// If creating both a key and value at the same time, use the provided
+// convenience function instead -- Int64Slice(name, value).
+func (k Key) Int64Slice(v []int64) KeyValue {
+	return KeyValue{
+		Key:   k,
+		Value: Int64SliceValue(v),
+	}
+}
+
+// Float64 creates a KeyValue instance with a FLOAT64 Value.
+//
+// If creating both a key and value at the same time, use the provided
+// convenience function instead -- Float64(name, value).
+func (k Key) Float64(v float64) KeyValue {
+	return KeyValue{
+		Key:   k,
+		Value: Float64Value(v),
+	}
+}
+
+// Float64Slice creates a KeyValue instance with a FLOAT64SLICE Value.
+//
+// If creating both a key and value at the same time, use the provided
+// convenience function instead -- Float64(name, value).
+func (k Key) Float64Slice(v []float64) KeyValue {
+	return KeyValue{
+		Key:   k,
+		Value: Float64SliceValue(v),
+	}
+}
+
+// String creates a KeyValue instance with a STRING Value.
+//
+// If creating both a key and value at the same time, use the provided
+// convenience function instead -- String(name, value).
+func (k Key) String(v string) KeyValue {
+	return KeyValue{
+		Key:   k,
+		Value: StringValue(v),
+	}
+}
+
+// StringSlice creates a KeyValue instance with a STRINGSLICE Value.
+//
+// If creating both a key and value at the same time, use the provided
+// convenience function instead -- StringSlice(name, value).
+func (k Key) StringSlice(v []string) KeyValue {
+	return KeyValue{
+		Key:   k,
+		Value: StringSliceValue(v),
+	}
+}
+
+// Defined returns true for non-empty keys.
+func (k Key) Defined() bool {
+	return len(k) != 0
+}

vendor/go.opentelemetry.io/otel/attribute/kv.go

@@ -0,0 +1,86 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package attribute // import "go.opentelemetry.io/otel/attribute"
+
+import (
+	"fmt"
+)
+
+// KeyValue holds a key and value pair.
+type KeyValue struct {
+	Key   Key
+	Value Value
+}
+
+// Valid returns if kv is a valid OpenTelemetry attribute.
+func (kv KeyValue) Valid() bool {
+	return kv.Key.Defined() && kv.Value.Type() != INVALID
+}
+
+// Bool creates a KeyValue with a BOOL Value type.
+func Bool(k string, v bool) KeyValue {
+	return Key(k).Bool(v)
+}
+
+// BoolSlice creates a KeyValue with a BOOLSLICE Value type.
+func BoolSlice(k string, v []bool) KeyValue {
+	return Key(k).BoolSlice(v)
+}
+
+// Int creates a KeyValue with an INT64 Value type.
+func Int(k string, v int) KeyValue {
+	return Key(k).Int(v)
+}
+
+// IntSlice creates a KeyValue with an INT64SLICE Value type.
+func IntSlice(k string, v []int) KeyValue {
+	return Key(k).IntSlice(v)
+}
+
+// Int64 creates a KeyValue with an INT64 Value type.
+func Int64(k string, v int64) KeyValue {
+	return Key(k).Int64(v)
+}
+
+// Int64Slice creates a KeyValue with an INT64SLICE Value type.
+func Int64Slice(k string, v []int64) KeyValue {
+	return Key(k).Int64Slice(v)
+}
+
+// Float64 creates a KeyValue with a FLOAT64 Value type.
+func Float64(k string, v float64) KeyValue {
+	return Key(k).Float64(v)
+}
+
+// Float64Slice creates a KeyValue with a FLOAT64SLICE Value type.
+func Float64Slice(k string, v []float64) KeyValue {
+	return Key(k).Float64Slice(v)
+}
+
+// String creates a KeyValue with a STRING Value type.
+func String(k, v string) KeyValue {
+	return Key(k).String(v)
+}
+
+// StringSlice creates a KeyValue with a STRINGSLICE Value type.
+func StringSlice(k string, v []string) KeyValue {
+	return Key(k).StringSlice(v)
+}
+
+// Stringer creates a new key-value pair with a passed name and a string
+// value generated by the passed Stringer interface.
+func Stringer(k string, v fmt.Stringer) KeyValue {
+	return Key(k).String(v.String())
+}

vendor/go.opentelemetry.io/otel/attribute/set.go

@@ -0,0 +1,435 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package attribute // import "go.opentelemetry.io/otel/attribute"
+
+import (
+	"encoding/json"
+	"reflect"
+	"sort"
+)
+
+type (
+	// Set is the representation for a distinct label set.  It
+	// manages an immutable set of labels, with an internal cache
+	// for storing label encodings.
+	//
+	// This type supports the `Equivalent` method of comparison
+	// using values of type `Distinct`.
+	//
+	// This type is used to implement:
+	// 1. Metric labels
+	// 2. Resource sets
+	// 3. Correlation map (TODO)
+	Set struct {
+		equivalent Distinct
+	}
+
+	// Distinct wraps a variable-size array of `KeyValue`,
+	// constructed with keys in sorted order.  This can be used as
+	// a map key or for equality checking between Sets.
+	Distinct struct {
+		iface interface{}
+	}
+
+	// Filter supports removing certain labels from label sets.
+	// When the filter returns true, the label will be kept in
+	// the filtered label set.  When the filter returns false, the
+	// label is excluded from the filtered label set, and the
+	// label instead appears in the `removed` list of excluded labels.
+	Filter func(KeyValue) bool
+
+	// Sortable implements `sort.Interface`, used for sorting
+	// `KeyValue`.  This is an exported type to support a
+	// memory optimization.  A pointer to one of these is needed
+	// for the call to `sort.Stable()`, which the caller may
+	// provide in order to avoid an allocation.  See
+	// `NewSetWithSortable()`.
+	Sortable []KeyValue
+)
+
+var (
+	// keyValueType is used in `computeDistinctReflect`.
+	keyValueType = reflect.TypeOf(KeyValue{})
+
+	// emptySet is returned for empty label sets.
+	emptySet = &Set{
+		equivalent: Distinct{
+			iface: [0]KeyValue{},
+		},
+	}
+)
+
+// EmptySet returns a reference to a Set with no elements.
+//
+// This is a convenience provided for optimized calling utility.
+func EmptySet() *Set {
+	return emptySet
+}
+
+// reflect abbreviates `reflect.ValueOf`.
+func (d Distinct) reflect() reflect.Value {
+	return reflect.ValueOf(d.iface)
+}
+
+// Valid returns true if this value refers to a valid `*Set`.
+func (d Distinct) Valid() bool {
+	return d.iface != nil
+}
+
+// Len returns the number of labels in this set.
+func (l *Set) Len() int {
+	if l == nil || !l.equivalent.Valid() {
+		return 0
+	}
+	return l.equivalent.reflect().Len()
+}
+
+// Get returns the KeyValue at ordered position `idx` in this set.
+func (l *Set) Get(idx int) (KeyValue, bool) {
+	if l == nil {
+		return KeyValue{}, false
+	}
+	value := l.equivalent.reflect()
+
+	if idx >= 0 && idx < value.Len() {
+		// Note: The Go compiler successfully avoids an allocation for
+		// the interface{} conversion here:
+		return value.Index(idx).Interface().(KeyValue), true
+	}
+
+	return KeyValue{}, false
+}
+
+// Value returns the value of a specified key in this set.
+func (l *Set) Value(k Key) (Value, bool) {
+	if l == nil {
+		return Value{}, false
+	}
+	rValue := l.equivalent.reflect()
+	vlen := rValue.Len()
+
+	idx := sort.Search(vlen, func(idx int) bool {
+		return rValue.Index(idx).Interface().(KeyValue).Key >= k
+	})
+	if idx >= vlen {
+		return Value{}, false
+	}
+	keyValue := rValue.Index(idx).Interface().(KeyValue)
+	if k == keyValue.Key {
+		return keyValue.Value, true
+	}
+	return Value{}, false
+}
+
+// HasValue tests whether a key is defined in this set.
+func (l *Set) HasValue(k Key) bool {
+	if l == nil {
+		return false
+	}
+	_, ok := l.Value(k)
+	return ok
+}
+
+// Iter returns an iterator for visiting the labels in this set.
+func (l *Set) Iter() Iterator {
+	return Iterator{
+		storage: l,
+		idx:     -1,
+	}
+}
+
+// ToSlice returns the set of labels belonging to this set, sorted,
+// where keys appear no more than once.
+func (l *Set) ToSlice() []KeyValue {
+	iter := l.Iter()
+	return iter.ToSlice()
+}
+
+// Equivalent returns a value that may be used as a map key.  The
+// Distinct type guarantees that the result will equal the equivalent
+// Distinct value of any label set with the same elements as this,
+// where sets are made unique by choosing the last value in the input
+// for any given key.
+func (l *Set) Equivalent() Distinct {
+	if l == nil || !l.equivalent.Valid() {
+		return emptySet.equivalent
+	}
+	return l.equivalent
+}
+
+// Equals returns true if the argument set is equivalent to this set.
+func (l *Set) Equals(o *Set) bool {
+	return l.Equivalent() == o.Equivalent()
+}
+
+// Encoded returns the encoded form of this set, according to
+// `encoder`.
+func (l *Set) Encoded(encoder Encoder) string {
+	if l == nil || encoder == nil {
+		return ""
+	}
+
+	return encoder.Encode(l.Iter())
+}
+
+func empty() Set {
+	return Set{
+		equivalent: emptySet.equivalent,
+	}
+}
+
+// NewSet returns a new `Set`.  See the documentation for
+// `NewSetWithSortableFiltered` for more details.
+//
+// Except for empty sets, this method adds an additional allocation
+// compared with calls that include a `*Sortable`.
+func NewSet(kvs ...KeyValue) Set {
+	// Check for empty set.
+	if len(kvs) == 0 {
+		return empty()
+	}
+	s, _ := NewSetWithSortableFiltered(kvs, new(Sortable), nil)
+	return s
+}
+
+// NewSetWithSortable returns a new `Set`.  See the documentation for
+// `NewSetWithSortableFiltered` for more details.
+//
+// This call includes a `*Sortable` option as a memory optimization.
+func NewSetWithSortable(kvs []KeyValue, tmp *Sortable) Set {
+	// Check for empty set.
+	if len(kvs) == 0 {
+		return empty()
+	}
+	s, _ := NewSetWithSortableFiltered(kvs, tmp, nil)
+	return s
+}
+
+// NewSetWithFiltered returns a new `Set`.  See the documentation for
+// `NewSetWithSortableFiltered` for more details.
+//
+// This call includes a `Filter` to include/exclude label keys from
+// the return value.  Excluded keys are returned as a slice of label
+// values.
+func NewSetWithFiltered(kvs []KeyValue, filter Filter) (Set, []KeyValue) {
+	// Check for empty set.
+	if len(kvs) == 0 {
+		return empty(), nil
+	}
+	return NewSetWithSortableFiltered(kvs, new(Sortable), filter)
+}
+
+// NewSetWithSortableFiltered returns a new `Set`.
+//
+// Duplicate keys are eliminated by taking the last value.  This
+// re-orders the input slice so that unique last-values are contiguous
+// at the end of the slice.
+//
+// This ensures the following:
+//
+// - Last-value-wins semantics
+// - Caller sees the reordering, but doesn't lose values
+// - Repeated call preserve last-value wins.
+//
+// Note that methods are defined on `*Set`, although this returns `Set`.
+// Callers can avoid memory allocations by:
+//
+// - allocating a `Sortable` for use as a temporary in this method
+// - allocating a `Set` for storing the return value of this
+//   constructor.
+//
+// The result maintains a cache of encoded labels, by attribute.EncoderID.
+// This value should not be copied after its first use.
+//
+// The second `[]KeyValue` return value is a list of labels that were
+// excluded by the Filter (if non-nil).
+func NewSetWithSortableFiltered(kvs []KeyValue, tmp *Sortable, filter Filter) (Set, []KeyValue) {
+	// Check for empty set.
+	if len(kvs) == 0 {
+		return empty(), nil
+	}
+
+	*tmp = kvs
+
+	// Stable sort so the following de-duplication can implement
+	// last-value-wins semantics.
+	sort.Stable(tmp)
+
+	*tmp = nil
+
+	position := len(kvs) - 1
+	offset := position - 1
+
+	// The requirements stated above require that the stable
+	// result be placed in the end of the input slice, while
+	// overwritten values are swapped to the beginning.
+	//
+	// De-duplicate with last-value-wins semantics.  Preserve
+	// duplicate values at the beginning of the input slice.
+	for ; offset >= 0; offset-- {
+		if kvs[offset].Key == kvs[position].Key {
+			continue
+		}
+		position--
+		kvs[offset], kvs[position] = kvs[position], kvs[offset]
+	}
+	if filter != nil {
+		return filterSet(kvs[position:], filter)
+	}
+	return Set{
+		equivalent: computeDistinct(kvs[position:]),
+	}, nil
+}
+
+// filterSet reorders `kvs` so that included keys are contiguous at
+// the end of the slice, while excluded keys precede the included keys.
+func filterSet(kvs []KeyValue, filter Filter) (Set, []KeyValue) {
+	var excluded []KeyValue
+
+	// Move labels that do not match the filter so
+	// they're adjacent before calling computeDistinct().
+	distinctPosition := len(kvs)
+
+	// Swap indistinct keys forward and distinct keys toward the
+	// end of the slice.
+	offset := len(kvs) - 1
+	for ; offset >= 0; offset-- {
+		if filter(kvs[offset]) {
+			distinctPosition--
+			kvs[offset], kvs[distinctPosition] = kvs[distinctPosition], kvs[offset]
+			continue
+		}
+	}
+	excluded = kvs[:distinctPosition]
+
+	return Set{
+		equivalent: computeDistinct(kvs[distinctPosition:]),
+	}, excluded
+}
+
+// Filter returns a filtered copy of this `Set`.  See the
+// documentation for `NewSetWithSortableFiltered` for more details.
+func (l *Set) Filter(re Filter) (Set, []KeyValue) {
+	if re == nil {
+		return Set{
+			equivalent: l.equivalent,
+		}, nil
+	}
+
+	// Note: This could be refactored to avoid the temporary slice
+	// allocation, if it proves to be expensive.
+	return filterSet(l.ToSlice(), re)
+}
+
+// computeDistinct returns a `Distinct` using either the fixed- or
+// reflect-oriented code path, depending on the size of the input.
+// The input slice is assumed to already be sorted and de-duplicated.
+func computeDistinct(kvs []KeyValue) Distinct {
+	iface := computeDistinctFixed(kvs)
+	if iface == nil {
+		iface = computeDistinctReflect(kvs)
+	}
+	return Distinct{
+		iface: iface,
+	}
+}
+
+// computeDistinctFixed computes a `Distinct` for small slices.  It
+// returns nil if the input is too large for this code path.
+func computeDistinctFixed(kvs []KeyValue) interface{} {
+	switch len(kvs) {
+	case 1:
+		ptr := new([1]KeyValue)
+		copy((*ptr)[:], kvs)
+		return *ptr
+	case 2:
+		ptr := new([2]KeyValue)
+		copy((*ptr)[:], kvs)
+		return *ptr
+	case 3:
+		ptr := new([3]KeyValue)
+		copy((*ptr)[:], kvs)
+		return *ptr
+	case 4:
+		ptr := new([4]KeyValue)
+		copy((*ptr)[:], kvs)
+		return *ptr
+	case 5:
+		ptr := new([5]KeyValue)
+		copy((*ptr)[:], kvs)
+		return *ptr
+	case 6:
+		ptr := new([6]KeyValue)
+		copy((*ptr)[:], kvs)
+		return *ptr
+	case 7:
+		ptr := new([7]KeyValue)
+		copy((*ptr)[:], kvs)
+		return *ptr
+	case 8:
+		ptr := new([8]KeyValue)
+		copy((*ptr)[:], kvs)
+		return *ptr
+	case 9:
+		ptr := new([9]KeyValue)
+		copy((*ptr)[:], kvs)
+		return *ptr
+	case 10:
+		ptr := new([10]KeyValue)
+		copy((*ptr)[:], kvs)
+		return *ptr
+	default:
+		return nil
+	}
+}
+
+// computeDistinctReflect computes a `Distinct` using reflection,
+// works for any size input.
+func computeDistinctReflect(kvs []KeyValue) interface{} {
+	at := reflect.New(reflect.ArrayOf(len(kvs), keyValueType)).Elem()
+	for i, keyValue := range kvs {
+		*(at.Index(i).Addr().Interface().(*KeyValue)) = keyValue
+	}
+	return at.Interface()
+}
+
+// MarshalJSON returns the JSON encoding of the `*Set`.
+func (l *Set) MarshalJSON() ([]byte, error) {
+	return json.Marshal(l.equivalent.iface)
+}
+
+// MarshalLog is the marshaling function used by the logging system to represent this exporter.
+func (l Set) MarshalLog() interface{} {
+	kvs := make(map[string]string)
+	for _, kv := range l.ToSlice() {
+		kvs[string(kv.Key)] = kv.Value.Emit()
+	}
+	return kvs
+}
+
+// Len implements `sort.Interface`.
+func (l *Sortable) Len() int {
+	return len(*l)
+}
+
+// Swap implements `sort.Interface`.
+func (l *Sortable) Swap(i, j int) {
+	(*l)[i], (*l)[j] = (*l)[j], (*l)[i]
+}
+
+// Less implements `sort.Interface`.
+func (l *Sortable) Less(i, j int) bool {
+	return (*l)[i].Key < (*l)[j].Key
+}

vendor/go.opentelemetry.io/otel/attribute/type_string.go

@@ -0,0 +1,31 @@
+// Code generated by "stringer -type=Type"; DO NOT EDIT.
+
+package attribute
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[INVALID-0]
+	_ = x[BOOL-1]
+	_ = x[INT64-2]
+	_ = x[FLOAT64-3]
+	_ = x[STRING-4]
+	_ = x[BOOLSLICE-5]
+	_ = x[INT64SLICE-6]
+	_ = x[FLOAT64SLICE-7]
+	_ = x[STRINGSLICE-8]
+}
+
+const _Type_name = "INVALIDBOOLINT64FLOAT64STRINGBOOLSLICEINT64SLICEFLOAT64SLICESTRINGSLICE"
+
+var _Type_index = [...]uint8{0, 7, 11, 16, 23, 29, 38, 48, 60, 71}
+
+func (i Type) String() string {
+	if i < 0 || i >= Type(len(_Type_index)-1) {
+		return "Type(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+	return _Type_name[_Type_index[i]:_Type_index[i+1]]
+}

vendor/go.opentelemetry.io/otel/attribute/value.go

@@ -0,0 +1,271 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package attribute // import "go.opentelemetry.io/otel/attribute"
+
+import (
+	"encoding/json"
+	"fmt"
+	"strconv"
+
+	"go.opentelemetry.io/otel/internal"
+)
+
+//go:generate stringer -type=Type
+
+// Type describes the type of the data Value holds.
+type Type int
+
+// Value represents the value part in key-value pairs.
+type Value struct {
+	vtype    Type
+	numeric  uint64
+	stringly string
+	slice    interface{}
+}
+
+const (
+	// INVALID is used for a Value with no value set.
+	INVALID Type = iota
+	// BOOL is a boolean Type Value.
+	BOOL
+	// INT64 is a 64-bit signed integral Type Value.
+	INT64
+	// FLOAT64 is a 64-bit floating point Type Value.
+	FLOAT64
+	// STRING is a string Type Value.
+	STRING
+	// BOOLSLICE is a slice of booleans Type Value.
+	BOOLSLICE
+	// INT64SLICE is a slice of 64-bit signed integral numbers Type Value.
+	INT64SLICE
+	// FLOAT64SLICE is a slice of 64-bit floating point numbers Type Value.
+	FLOAT64SLICE
+	// STRINGSLICE is a slice of strings Type Value.
+	STRINGSLICE
+)
+
+// BoolValue creates a BOOL Value.
+func BoolValue(v bool) Value {
+	return Value{
+		vtype:   BOOL,
+		numeric: internal.BoolToRaw(v),
+	}
+}
+
+// BoolSliceValue creates a BOOLSLICE Value.
+func BoolSliceValue(v []bool) Value {
+	cp := make([]bool, len(v))
+	copy(cp, v)
+	return Value{
+		vtype: BOOLSLICE,
+		slice: &cp,
+	}
+}
+
+// IntValue creates an INT64 Value.
+func IntValue(v int) Value {
+	return Int64Value(int64(v))
+}
+
+// IntSliceValue creates an INTSLICE Value.
+func IntSliceValue(v []int) Value {
+	cp := make([]int64, 0, len(v))
+	for _, i := range v {
+		cp = append(cp, int64(i))
+	}
+	return Value{
+		vtype: INT64SLICE,
+		slice: &cp,
+	}
+}
+
+// Int64Value creates an INT64 Value.
+func Int64Value(v int64) Value {
+	return Value{
+		vtype:   INT64,
+		numeric: internal.Int64ToRaw(v),
+	}
+}
+
+// Int64SliceValue creates an INT64SLICE Value.
+func Int64SliceValue(v []int64) Value {
+	cp := make([]int64, len(v))
+	copy(cp, v)
+	return Value{
+		vtype: INT64SLICE,
+		slice: &cp,
+	}
+}
+
+// Float64Value creates a FLOAT64 Value.
+func Float64Value(v float64) Value {
+	return Value{
+		vtype:   FLOAT64,
+		numeric: internal.Float64ToRaw(v),
+	}
+}
+
+// Float64SliceValue creates a FLOAT64SLICE Value.
+func Float64SliceValue(v []float64) Value {
+	cp := make([]float64, len(v))
+	copy(cp, v)
+	return Value{
+		vtype: FLOAT64SLICE,
+		slice: &cp,
+	}
+}
+
+// StringValue creates a STRING Value.
+func StringValue(v string) Value {
+	return Value{
+		vtype:    STRING,
+		stringly: v,
+	}
+}
+
+// StringSliceValue creates a STRINGSLICE Value.
+func StringSliceValue(v []string) Value {
+	cp := make([]string, len(v))
+	copy(cp, v)
+	return Value{
+		vtype: STRINGSLICE,
+		slice: &cp,
+	}
+}
+
+// Type returns a type of the Value.
+func (v Value) Type() Type {
+	return v.vtype
+}
+
+// AsBool returns the bool value. Make sure that the Value's type is
+// BOOL.
+func (v Value) AsBool() bool {
+	return internal.RawToBool(v.numeric)
+}
+
+// AsBoolSlice returns the []bool value. Make sure that the Value's type is
+// BOOLSLICE.
+func (v Value) AsBoolSlice() []bool {
+	if s, ok := v.slice.(*[]bool); ok {
+		return *s
+	}
+	return nil
+}
+
+// AsInt64 returns the int64 value. Make sure that the Value's type is
+// INT64.
+func (v Value) AsInt64() int64 {
+	return internal.RawToInt64(v.numeric)
+}
+
+// AsInt64Slice returns the []int64 value. Make sure that the Value's type is
+// INT64SLICE.
+func (v Value) AsInt64Slice() []int64 {
+	if s, ok := v.slice.(*[]int64); ok {
+		return *s
+	}
+	return nil
+}
+
+// AsFloat64 returns the float64 value. Make sure that the Value's
+// type is FLOAT64.
+func (v Value) AsFloat64() float64 {
+	return internal.RawToFloat64(v.numeric)
+}
+
+// AsFloat64Slice returns the []float64 value. Make sure that the Value's type is
+// FLOAT64SLICE.
+func (v Value) AsFloat64Slice() []float64 {
+	if s, ok := v.slice.(*[]float64); ok {
+		return *s
+	}
+	return nil
+}
+
+// AsString returns the string value. Make sure that the Value's type
+// is STRING.
+func (v Value) AsString() string {
+	return v.stringly
+}
+
+// AsStringSlice returns the []string value. Make sure that the Value's type is
+// STRINGSLICE.
+func (v Value) AsStringSlice() []string {
+	if s, ok := v.slice.(*[]string); ok {
+		return *s
+	}
+	return nil
+}
+
+type unknownValueType struct{}
+
+// AsInterface returns Value's data as interface{}.
+func (v Value) AsInterface() interface{} {
+	switch v.Type() {
+	case BOOL:
+		return v.AsBool()
+	case BOOLSLICE:
+		return v.AsBoolSlice()
+	case INT64:
+		return v.AsInt64()
+	case INT64SLICE:
+		return v.AsInt64Slice()
+	case FLOAT64:
+		return v.AsFloat64()
+	case FLOAT64SLICE:
+		return v.AsFloat64Slice()
+	case STRING:
+		return v.stringly
+	case STRINGSLICE:
+		return v.AsStringSlice()
+	}
+	return unknownValueType{}
+}
+
+// Emit returns a string representation of Value's data.
+func (v Value) Emit() string {
+	switch v.Type() {
+	case BOOLSLICE:
+		return fmt.Sprint(*(v.slice.(*[]bool)))
+	case BOOL:
+		return strconv.FormatBool(v.AsBool())
+	case INT64SLICE:
+		return fmt.Sprint(*(v.slice.(*[]int64)))
+	case INT64:
+		return strconv.FormatInt(v.AsInt64(), 10)
+	case FLOAT64SLICE:
+		return fmt.Sprint(*(v.slice.(*[]float64)))
+	case FLOAT64:
+		return fmt.Sprint(v.AsFloat64())
+	case STRINGSLICE:
+		return fmt.Sprint(*(v.slice.(*[]string)))
+	case STRING:
+		return v.stringly
+	default:
+		return "unknown"
+	}
+}
+
+// MarshalJSON returns the JSON encoding of the Value.
+func (v Value) MarshalJSON() ([]byte, error) {
+	var jsonVal struct {
+		Type  string
+		Value interface{}
+	}
+	jsonVal.Type = v.Type().String()
+	jsonVal.Value = v.AsInterface()
+	return json.Marshal(jsonVal)
+}

vendor/go.opentelemetry.io/otel/baggage/baggage.go

@@ -0,0 +1,556 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package baggage // import "go.opentelemetry.io/otel/baggage"
+
+import (
+	"errors"
+	"fmt"
+	"net/url"
+	"regexp"
+	"strings"
+
+	"go.opentelemetry.io/otel/internal/baggage"
+)
+
+const (
+	maxMembers               = 180
+	maxBytesPerMembers       = 4096
+	maxBytesPerBaggageString = 8192
+
+	listDelimiter     = ","
+	keyValueDelimiter = "="
+	propertyDelimiter = ";"
+
+	keyDef      = `([\x21\x23-\x27\x2A\x2B\x2D\x2E\x30-\x39\x41-\x5a\x5e-\x7a\x7c\x7e]+)`
+	valueDef    = `([\x21\x23-\x2b\x2d-\x3a\x3c-\x5B\x5D-\x7e]*)`
+	keyValueDef = `\s*` + keyDef + `\s*` + keyValueDelimiter + `\s*` + valueDef + `\s*`
+)
+
+var (
+	keyRe      = regexp.MustCompile(`^` + keyDef + `$`)
+	valueRe    = regexp.MustCompile(`^` + valueDef + `$`)
+	propertyRe = regexp.MustCompile(`^(?:\s*` + keyDef + `\s*|` + keyValueDef + `)$`)
+)
+
+var (
+	errInvalidKey      = errors.New("invalid key")
+	errInvalidValue    = errors.New("invalid value")
+	errInvalidProperty = errors.New("invalid baggage list-member property")
+	errInvalidMember   = errors.New("invalid baggage list-member")
+	errMemberNumber    = errors.New("too many list-members in baggage-string")
+	errMemberBytes     = errors.New("list-member too large")
+	errBaggageBytes    = errors.New("baggage-string too large")
+)
+
+// Property is an additional metadata entry for a baggage list-member.
+type Property struct {
+	key, value string
+
+	// hasValue indicates if a zero-value value means the property does not
+	// have a value or if it was the zero-value.
+	hasValue bool
+
+	// hasData indicates whether the created property contains data or not.
+	// Properties that do not contain data are invalid with no other check
+	// required.
+	hasData bool
+}
+
+func NewKeyProperty(key string) (Property, error) {
+	if !keyRe.MatchString(key) {
+		return newInvalidProperty(), fmt.Errorf("%w: %q", errInvalidKey, key)
+	}
+
+	p := Property{key: key, hasData: true}
+	return p, nil
+}
+
+func NewKeyValueProperty(key, value string) (Property, error) {
+	if !keyRe.MatchString(key) {
+		return newInvalidProperty(), fmt.Errorf("%w: %q", errInvalidKey, key)
+	}
+	if !valueRe.MatchString(value) {
+		return newInvalidProperty(), fmt.Errorf("%w: %q", errInvalidValue, value)
+	}
+
+	p := Property{
+		key:      key,
+		value:    value,
+		hasValue: true,
+		hasData:  true,
+	}
+	return p, nil
+}
+
+func newInvalidProperty() Property {
+	return Property{}
+}
+
+// parseProperty attempts to decode a Property from the passed string. It
+// returns an error if the input is invalid according to the W3C Baggage
+// specification.
+func parseProperty(property string) (Property, error) {
+	if property == "" {
+		return newInvalidProperty(), nil
+	}
+
+	match := propertyRe.FindStringSubmatch(property)
+	if len(match) != 4 {
+		return newInvalidProperty(), fmt.Errorf("%w: %q", errInvalidProperty, property)
+	}
+
+	p := Property{hasData: true}
+	if match[1] != "" {
+		p.key = match[1]
+	} else {
+		p.key = match[2]
+		p.value = match[3]
+		p.hasValue = true
+	}
+
+	return p, nil
+}
+
+// validate ensures p conforms to the W3C Baggage specification, returning an
+// error otherwise.
+func (p Property) validate() error {
+	errFunc := func(err error) error {
+		return fmt.Errorf("invalid property: %w", err)
+	}
+
+	if !p.hasData {
+		return errFunc(fmt.Errorf("%w: %q", errInvalidProperty, p))
+	}
+
+	if !keyRe.MatchString(p.key) {
+		return errFunc(fmt.Errorf("%w: %q", errInvalidKey, p.key))
+	}
+	if p.hasValue && !valueRe.MatchString(p.value) {
+		return errFunc(fmt.Errorf("%w: %q", errInvalidValue, p.value))
+	}
+	if !p.hasValue && p.value != "" {
+		return errFunc(errors.New("inconsistent value"))
+	}
+	return nil
+}
+
+// Key returns the Property key.
+func (p Property) Key() string {
+	return p.key
+}
+
+// Value returns the Property value. Additionally a boolean value is returned
+// indicating if the returned value is the empty if the Property has a value
+// that is empty or if the value is not set.
+func (p Property) Value() (string, bool) {
+	return p.value, p.hasValue
+}
+
+// String encodes Property into a string compliant with the W3C Baggage
+// specification.
+func (p Property) String() string {
+	if p.hasValue {
+		return fmt.Sprintf("%s%s%v", p.key, keyValueDelimiter, p.value)
+	}
+	return p.key
+}
+
+type properties []Property
+
+func fromInternalProperties(iProps []baggage.Property) properties {
+	if len(iProps) == 0 {
+		return nil
+	}
+
+	props := make(properties, len(iProps))
+	for i, p := range iProps {
+		props[i] = Property{
+			key:      p.Key,
+			value:    p.Value,
+			hasValue: p.HasValue,
+		}
+	}
+	return props
+}
+
+func (p properties) asInternal() []baggage.Property {
+	if len(p) == 0 {
+		return nil
+	}
+
+	iProps := make([]baggage.Property, len(p))
+	for i, prop := range p {
+		iProps[i] = baggage.Property{
+			Key:      prop.key,
+			Value:    prop.value,
+			HasValue: prop.hasValue,
+		}
+	}
+	return iProps
+}
+
+func (p properties) Copy() properties {
+	if len(p) == 0 {
+		return nil
+	}
+
+	props := make(properties, len(p))
+	copy(props, p)
+	return props
+}
+
+// validate ensures each Property in p conforms to the W3C Baggage
+// specification, returning an error otherwise.
+func (p properties) validate() error {
+	for _, prop := range p {
+		if err := prop.validate(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// String encodes properties into a string compliant with the W3C Baggage
+// specification.
+func (p properties) String() string {
+	props := make([]string, len(p))
+	for i, prop := range p {
+		props[i] = prop.String()
+	}
+	return strings.Join(props, propertyDelimiter)
+}
+
+// Member is a list-member of a baggage-string as defined by the W3C Baggage
+// specification.
+type Member struct {
+	key, value string
+	properties properties
+
+	// hasData indicates whether the created property contains data or not.
+	// Properties that do not contain data are invalid with no other check
+	// required.
+	hasData bool
+}
+
+// NewMember returns a new Member from the passed arguments. An error is
+// returned if the created Member would be invalid according to the W3C
+// Baggage specification.
+func NewMember(key, value string, props ...Property) (Member, error) {
+	m := Member{
+		key:        key,
+		value:      value,
+		properties: properties(props).Copy(),
+		hasData:    true,
+	}
+	if err := m.validate(); err != nil {
+		return newInvalidMember(), err
+	}
+
+	return m, nil
+}
+
+func newInvalidMember() Member {
+	return Member{}
+}
+
+// parseMember attempts to decode a Member from the passed string. It returns
+// an error if the input is invalid according to the W3C Baggage
+// specification.
+func parseMember(member string) (Member, error) {
+	if n := len(member); n > maxBytesPerMembers {
+		return newInvalidMember(), fmt.Errorf("%w: %d", errMemberBytes, n)
+	}
+
+	var (
+		key, value string
+		props      properties
+	)
+
+	parts := strings.SplitN(member, propertyDelimiter, 2)
+	switch len(parts) {
+	case 2:
+		// Parse the member properties.
+		for _, pStr := range strings.Split(parts[1], propertyDelimiter) {
+			p, err := parseProperty(pStr)
+			if err != nil {
+				return newInvalidMember(), err
+			}
+			props = append(props, p)
+		}
+		fallthrough
+	case 1:
+		// Parse the member key/value pair.
+
+		// Take into account a value can contain equal signs (=).
+		kv := strings.SplitN(parts[0], keyValueDelimiter, 2)
+		if len(kv) != 2 {
+			return newInvalidMember(), fmt.Errorf("%w: %q", errInvalidMember, member)
+		}
+		// "Leading and trailing whitespaces are allowed but MUST be trimmed
+		// when converting the header into a data structure."
+		key = strings.TrimSpace(kv[0])
+		var err error
+		value, err = url.QueryUnescape(strings.TrimSpace(kv[1]))
+		if err != nil {
+			return newInvalidMember(), fmt.Errorf("%w: %q", err, value)
+		}
+		if !keyRe.MatchString(key) {
+			return newInvalidMember(), fmt.Errorf("%w: %q", errInvalidKey, key)
+		}
+		if !valueRe.MatchString(value) {
+			return newInvalidMember(), fmt.Errorf("%w: %q", errInvalidValue, value)
+		}
+	default:
+		// This should never happen unless a developer has changed the string
+		// splitting somehow. Panic instead of failing silently and allowing
+		// the bug to slip past the CI checks.
+		panic("failed to parse baggage member")
+	}
+
+	return Member{key: key, value: value, properties: props, hasData: true}, nil
+}
+
+// validate ensures m conforms to the W3C Baggage specification, returning an
+// error otherwise.
+func (m Member) validate() error {
+	if !m.hasData {
+		return fmt.Errorf("%w: %q", errInvalidMember, m)
+	}
+
+	if !keyRe.MatchString(m.key) {
+		return fmt.Errorf("%w: %q", errInvalidKey, m.key)
+	}
+	if !valueRe.MatchString(m.value) {
+		return fmt.Errorf("%w: %q", errInvalidValue, m.value)
+	}
+	return m.properties.validate()
+}
+
+// Key returns the Member key.
+func (m Member) Key() string { return m.key }
+
+// Value returns the Member value.
+func (m Member) Value() string { return m.value }
+
+// Properties returns a copy of the Member properties.
+func (m Member) Properties() []Property { return m.properties.Copy() }
+
+// String encodes Member into a string compliant with the W3C Baggage
+// specification.
+func (m Member) String() string {
+	// A key is just an ASCII string, but a value is URL encoded UTF-8.
+	s := fmt.Sprintf("%s%s%s", m.key, keyValueDelimiter, url.QueryEscape(m.value))
+	if len(m.properties) > 0 {
+		s = fmt.Sprintf("%s%s%s", s, propertyDelimiter, m.properties.String())
+	}
+	return s
+}
+
+// Baggage is a list of baggage members representing the baggage-string as
+// defined by the W3C Baggage specification.
+type Baggage struct { //nolint:golint
+	list baggage.List
+}
+
+// New returns a new valid Baggage. It returns an error if it results in a
+// Baggage exceeding limits set in that specification.
+//
+// It expects all the provided members to have already been validated.
+func New(members ...Member) (Baggage, error) {
+	if len(members) == 0 {
+		return Baggage{}, nil
+	}
+
+	b := make(baggage.List)
+	for _, m := range members {
+		if !m.hasData {
+			return Baggage{}, errInvalidMember
+		}
+
+		// OpenTelemetry resolves duplicates by last-one-wins.
+		b[m.key] = baggage.Item{
+			Value:      m.value,
+			Properties: m.properties.asInternal(),
+		}
+	}
+
+	// Check member numbers after deduplicating.
+	if len(b) > maxMembers {
+		return Baggage{}, errMemberNumber
+	}
+
+	bag := Baggage{b}
+	if n := len(bag.String()); n > maxBytesPerBaggageString {
+		return Baggage{}, fmt.Errorf("%w: %d", errBaggageBytes, n)
+	}
+
+	return bag, nil
+}
+
+// Parse attempts to decode a baggage-string from the passed string. It
+// returns an error if the input is invalid according to the W3C Baggage
+// specification.
+//
+// If there are duplicate list-members contained in baggage, the last one
+// defined (reading left-to-right) will be the only one kept. This diverges
+// from the W3C Baggage specification which allows duplicate list-members, but
+// conforms to the OpenTelemetry Baggage specification.
+func Parse(bStr string) (Baggage, error) {
+	if bStr == "" {
+		return Baggage{}, nil
+	}
+
+	if n := len(bStr); n > maxBytesPerBaggageString {
+		return Baggage{}, fmt.Errorf("%w: %d", errBaggageBytes, n)
+	}
+
+	b := make(baggage.List)
+	for _, memberStr := range strings.Split(bStr, listDelimiter) {
+		m, err := parseMember(memberStr)
+		if err != nil {
+			return Baggage{}, err
+		}
+		// OpenTelemetry resolves duplicates by last-one-wins.
+		b[m.key] = baggage.Item{
+			Value:      m.value,
+			Properties: m.properties.asInternal(),
+		}
+	}
+
+	// OpenTelemetry does not allow for duplicate list-members, but the W3C
+	// specification does. Now that we have deduplicated, ensure the baggage
+	// does not exceed list-member limits.
+	if len(b) > maxMembers {
+		return Baggage{}, errMemberNumber
+	}
+
+	return Baggage{b}, nil
+}
+
+// Member returns the baggage list-member identified by key.
+//
+// If there is no list-member matching the passed key the returned Member will
+// be a zero-value Member.
+// The returned member is not validated, as we assume the validation happened
+// when it was added to the Baggage.
+func (b Baggage) Member(key string) Member {
+	v, ok := b.list[key]
+	if !ok {
+		// We do not need to worry about distiguising between the situation
+		// where a zero-valued Member is included in the Baggage because a
+		// zero-valued Member is invalid according to the W3C Baggage
+		// specification (it has an empty key).
+		return newInvalidMember()
+	}
+
+	return Member{
+		key:        key,
+		value:      v.Value,
+		properties: fromInternalProperties(v.Properties),
+	}
+}
+
+// Members returns all the baggage list-members.
+// The order of the returned list-members does not have significance.
+//
+// The returned members are not validated, as we assume the validation happened
+// when they were added to the Baggage.
+func (b Baggage) Members() []Member {
+	if len(b.list) == 0 {
+		return nil
+	}
+
+	members := make([]Member, 0, len(b.list))
+	for k, v := range b.list {
+		members = append(members, Member{
+			key:        k,
+			value:      v.Value,
+			properties: fromInternalProperties(v.Properties),
+		})
+	}
+	return members
+}
+
+// SetMember returns a copy the Baggage with the member included. If the
+// baggage contains a Member with the same key the existing Member is
+// replaced.
+//
+// If member is invalid according to the W3C Baggage specification, an error
+// is returned with the original Baggage.
+func (b Baggage) SetMember(member Member) (Baggage, error) {
+	if !member.hasData {
+		return b, errInvalidMember
+	}
+
+	n := len(b.list)
+	if _, ok := b.list[member.key]; !ok {
+		n++
+	}
+	list := make(baggage.List, n)
+
+	for k, v := range b.list {
+		// Do not copy if we are just going to overwrite.
+		if k == member.key {
+			continue
+		}
+		list[k] = v
+	}
+
+	list[member.key] = baggage.Item{
+		Value:      member.value,
+		Properties: member.properties.asInternal(),
+	}
+
+	return Baggage{list: list}, nil
+}
+
+// DeleteMember returns a copy of the Baggage with the list-member identified
+// by key removed.
+func (b Baggage) DeleteMember(key string) Baggage {
+	n := len(b.list)
+	if _, ok := b.list[key]; ok {
+		n--
+	}
+	list := make(baggage.List, n)
+
+	for k, v := range b.list {
+		if k == key {
+			continue
+		}
+		list[k] = v
+	}
+
+	return Baggage{list: list}
+}
+
+// Len returns the number of list-members in the Baggage.
+func (b Baggage) Len() int {
+	return len(b.list)
+}
+
+// String encodes Baggage into a string compliant with the W3C Baggage
+// specification. The returned string will be invalid if the Baggage contains
+// any invalid list-members.
+func (b Baggage) String() string {
+	members := make([]string, 0, len(b.list))
+	for k, v := range b.list {
+		members = append(members, Member{
+			key:        k,
+			value:      v.Value,
+			properties: fromInternalProperties(v.Properties),
+		}.String())
+	}
+	return strings.Join(members, listDelimiter)
+}

vendor/go.opentelemetry.io/otel/baggage/context.go

@@ -0,0 +1,39 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package baggage // import "go.opentelemetry.io/otel/baggage"
+
+import (
+	"context"
+
+	"go.opentelemetry.io/otel/internal/baggage"
+)
+
+// ContextWithBaggage returns a copy of parent with baggage.
+func ContextWithBaggage(parent context.Context, b Baggage) context.Context {
+	// Delegate so any hooks for the OpenTracing bridge are handled.
+	return baggage.ContextWithList(parent, b.list)
+}
+
+// ContextWithoutBaggage returns a copy of parent with no baggage.
+func ContextWithoutBaggage(parent context.Context) context.Context {
+	// Delegate so any hooks for the OpenTracing bridge are handled.
+	return baggage.ContextWithList(parent, nil)
+}
+
+// FromContext returns the baggage contained in ctx.
+func FromContext(ctx context.Context) Baggage {
+	// Delegate so any hooks for the OpenTracing bridge are handled.
+	return Baggage{list: baggage.ListFromContext(ctx)}
+}

vendor/go.opentelemetry.io/otel/baggage/doc.go

@@ -0,0 +1,20 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/*
+Package baggage provides functionality for storing and retrieving
+baggage items in Go context. For propagating the baggage, see the
+go.opentelemetry.io/otel/propagation package.
+*/
+package baggage // import "go.opentelemetry.io/otel/baggage"

vendor/go.opentelemetry.io/otel/codes/codes.go

@@ -0,0 +1,106 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package codes // import "go.opentelemetry.io/otel/codes"
+
+import (
+	"encoding/json"
+	"fmt"
+	"strconv"
+)
+
+const (
+	// Unset is the default status code.
+	Unset Code = 0
+	// Error indicates the operation contains an error.
+	Error Code = 1
+	// Ok indicates operation has been validated by an Application developers
+	// or Operator to have completed successfully, or contain no error.
+	Ok Code = 2
+
+	maxCode = 3
+)
+
+// Code is an 32-bit representation of a status state.
+type Code uint32
+
+var codeToStr = map[Code]string{
+	Unset: "Unset",
+	Error: "Error",
+	Ok:    "Ok",
+}
+
+var strToCode = map[string]Code{
+	`"Unset"`: Unset,
+	`"Error"`: Error,
+	`"Ok"`:    Ok,
+}
+
+// String returns the Code as a string.
+func (c Code) String() string {
+	return codeToStr[c]
+}
+
+// UnmarshalJSON unmarshals b into the Code.
+//
+// This is based on the functionality in the gRPC codes package:
+// https://github.com/grpc/grpc-go/blob/bb64fee312b46ebee26be43364a7a966033521b1/codes/codes.go#L218-L244
+func (c *Code) UnmarshalJSON(b []byte) error {
+	// From json.Unmarshaler: By convention, to approximate the behavior of
+	// Unmarshal itself, Unmarshalers implement UnmarshalJSON([]byte("null")) as
+	// a no-op.
+	if string(b) == "null" {
+		return nil
+	}
+	if c == nil {
+		return fmt.Errorf("nil receiver passed to UnmarshalJSON")
+	}
+
+	var x interface{}
+	if err := json.Unmarshal(b, &x); err != nil {
+		return err
+	}
+	switch x.(type) {
+	case string:
+		if jc, ok := strToCode[string(b)]; ok {
+			*c = jc
+			return nil
+		}
+		return fmt.Errorf("invalid code: %q", string(b))
+	case float64:
+		if ci, err := strconv.ParseUint(string(b), 10, 32); err == nil {
+			if ci >= maxCode {
+				return fmt.Errorf("invalid code: %q", ci)
+			}
+
+			*c = Code(ci)
+			return nil
+		}
+		return fmt.Errorf("invalid code: %q", string(b))
+	default:
+		return fmt.Errorf("invalid code: %q", string(b))
+	}
+}
+
+// MarshalJSON returns c as the JSON encoding of c.
+func (c *Code) MarshalJSON() ([]byte, error) {
+	if c == nil {
+		return []byte("null"), nil
+	}
+	str, ok := codeToStr[*c]
+	if !ok {
+		return nil, fmt.Errorf("invalid code: %d", *c)
+	}
+	return []byte(fmt.Sprintf("%q", str)), nil
+}

vendor/go.opentelemetry.io/otel/codes/doc.go

@@ -0,0 +1,21 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/*
+Package codes defines the canonical error codes used by OpenTelemetry.
+
+It conforms to [the OpenTelemetry
+specification](https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/trace/api.md#statuscanonicalcode).
+*/
+package codes // import "go.opentelemetry.io/otel/codes"

vendor/go.opentelemetry.io/otel/doc.go

@@ -0,0 +1,34 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/*
+Package otel provides global access to the OpenTelemetry API. The subpackages of
+the otel package provide an implementation of the OpenTelemetry API.
+
+The provided API is used to instrument code and measure data about that code's
+performance and operation. The measured data, by default, is not processed or
+transmitted anywhere. An implementation of the OpenTelemetry SDK, like the
+default SDK implementation (go.opentelemetry.io/otel/sdk), and associated
+exporters are used to process and transport this data.
+
+To read the getting started guide, see https://opentelemetry.io/docs/go/getting-started/.
+
+To read more about tracing, see go.opentelemetry.io/otel/trace.
+
+To read more about metrics, see go.opentelemetry.io/otel/metric.
+
+To read more about propagation, see go.opentelemetry.io/otel/propagation and
+go.opentelemetry.io/otel/baggage.
+*/
+package otel // import "go.opentelemetry.io/otel"

vendor/go.opentelemetry.io/otel/error_handler.go

@@ -0,0 +1,38 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package otel // import "go.opentelemetry.io/otel"
+
+// ErrorHandler handles irremediable events.
+type ErrorHandler interface {
+	// DO NOT CHANGE: any modification will not be backwards compatible and
+	// must never be done outside of a new major release.
+
+	// Handle handles any error deemed irremediable by an OpenTelemetry
+	// component.
+	Handle(error)
+	// DO NOT CHANGE: any modification will not be backwards compatible and
+	// must never be done outside of a new major release.
+}
+
+// ErrorHandlerFunc is a convenience adapter to allow the use of a function
+// as an ErrorHandler.
+type ErrorHandlerFunc func(error)
+
+var _ ErrorHandler = ErrorHandlerFunc(nil)
+
+// Handle handles the irremediable error by calling the ErrorHandlerFunc itself.
+func (f ErrorHandlerFunc) Handle(err error) {
+	f(err)
+}

vendor/go.opentelemetry.io/otel/get_main_pkgs.sh

@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+
+# Copyright The OpenTelemetry Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -euo pipefail
+
+top_dir='.'
+if [[ $# -gt 0 ]]; then
+    top_dir="${1}"
+fi
+
+p=$(pwd)
+mod_dirs=()
+
+# Note `mapfile` does not exist in older bash versions:
+# https://stackoverflow.com/questions/41475261/need-alternative-to-readarray-mapfile-for-script-on-older-version-of-bash
+
+while IFS= read -r line; do
+    mod_dirs+=("$line")
+done < <(find "${top_dir}" -type f -name 'go.mod' -exec dirname {} \; | sort)
+
+for mod_dir in "${mod_dirs[@]}"; do
+    cd "${mod_dir}"
+
+    while IFS= read -r line; do
+        echo ".${line#${p}}"
+    done < <(go list --find -f '{{.Name}}|{{.Dir}}' ./... | grep '^main|' | cut -f 2- -d '|')
+    cd "${p}"
+done

vendor/go.opentelemetry.io/otel/handler.go

@@ -0,0 +1,98 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package otel // import "go.opentelemetry.io/otel"
+
+import (
+	"log"
+	"os"
+	"sync"
+)
+
+var (
+	// globalErrorHandler provides an ErrorHandler that can be used
+	// throughout an OpenTelemetry instrumented project. When a user
+	// specified ErrorHandler is registered (`SetErrorHandler`) all calls to
+	// `Handle` and will be delegated to the registered ErrorHandler.
+	globalErrorHandler = defaultErrorHandler()
+
+	// Compile-time check that delegator implements ErrorHandler.
+	_ ErrorHandler = (*delegator)(nil)
+	// Compile-time check that errLogger implements ErrorHandler.
+	_ ErrorHandler = (*errLogger)(nil)
+)
+
+type delegator struct {
+	lock *sync.RWMutex
+	eh   ErrorHandler
+}
+
+func (d *delegator) Handle(err error) {
+	d.lock.RLock()
+	defer d.lock.RUnlock()
+	d.eh.Handle(err)
+}
+
+// setDelegate sets the ErrorHandler delegate.
+func (d *delegator) setDelegate(eh ErrorHandler) {
+	d.lock.Lock()
+	defer d.lock.Unlock()
+	d.eh = eh
+}
+
+func defaultErrorHandler() *delegator {
+	return &delegator{
+		lock: &sync.RWMutex{},
+		eh:   &errLogger{l: log.New(os.Stderr, "", log.LstdFlags)},
+	}
+
+}
+
+// errLogger logs errors if no delegate is set, otherwise they are delegated.
+type errLogger struct {
+	l *log.Logger
+}
+
+// Handle logs err if no delegate is set, otherwise it is delegated.
+func (h *errLogger) Handle(err error) {
+	h.l.Print(err)
+}
+
+// GetErrorHandler returns the global ErrorHandler instance.
+//
+// The default ErrorHandler instance returned will log all errors to STDERR
+// until an override ErrorHandler is set with SetErrorHandler. All
+// ErrorHandler returned prior to this will automatically forward errors to
+// the set instance instead of logging.
+//
+// Subsequent calls to SetErrorHandler after the first will not forward errors
+// to the new ErrorHandler for prior returned instances.
+func GetErrorHandler() ErrorHandler {
+	return globalErrorHandler
+}
+
+// SetErrorHandler sets the global ErrorHandler to h.
+//
+// The first time this is called all ErrorHandler previously returned from
+// GetErrorHandler will send errors to h instead of the default logging
+// ErrorHandler. Subsequent calls will set the global ErrorHandler, but not
+// delegate errors to h.
+func SetErrorHandler(h ErrorHandler) {
+	globalErrorHandler.setDelegate(h)
+}
+
+// Handle is a convenience function for ErrorHandler().Handle(err)
+func Handle(err error) {
+	GetErrorHandler().Handle(err)
+}

vendor/go.opentelemetry.io/otel/internal/baggage/baggage.go

@@ -0,0 +1,43 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/*
+Package baggage provides base types and functionality to store and retrieve
+baggage in Go context. This package exists because the OpenTracing bridge to
+OpenTelemetry needs to synchronize state whenever baggage for a context is
+modified and that context contains an OpenTracing span. If it were not for
+this need this package would not need to exist and the
+`go.opentelemetry.io/otel/baggage` package would be the singular place where
+W3C baggage is handled.
+*/
+package baggage // import "go.opentelemetry.io/otel/internal/baggage"
+
+// List is the collection of baggage members. The W3C allows for duplicates,
+// but OpenTelemetry does not, therefore, this is represented as a map.
+type List map[string]Item
+
+// Item is the value and metadata properties part of a list-member.
+type Item struct {
+	Value      string
+	Properties []Property
+}
+
+// Property is a metadata entry for a list-member.
+type Property struct {
+	Key, Value string
+
+	// HasValue indicates if a zero-value value means the property does not
+	// have a value or if it was the zero-value.
+	HasValue bool
+}

vendor/go.opentelemetry.io/otel/internal/baggage/context.go

@@ -0,0 +1,95 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package baggage // import "go.opentelemetry.io/otel/internal/baggage"
+
+import "context"
+
+type baggageContextKeyType int
+
+const baggageKey baggageContextKeyType = iota
+
+// SetHookFunc is a callback called when storing baggage in the context.
+type SetHookFunc func(context.Context, List) context.Context
+
+// GetHookFunc is a callback called when getting baggage from the context.
+type GetHookFunc func(context.Context, List) List
+
+type baggageState struct {
+	list List
+
+	setHook SetHookFunc
+	getHook GetHookFunc
+}
+
+// ContextWithSetHook returns a copy of parent with hook configured to be
+// invoked every time ContextWithBaggage is called.
+//
+// Passing nil SetHookFunc creates a context with no set hook to call.
+func ContextWithSetHook(parent context.Context, hook SetHookFunc) context.Context {
+	var s baggageState
+	switch v := parent.Value(baggageKey).(type) {
+	case baggageState:
+		s = v
+	}
+
+	s.setHook = hook
+	return context.WithValue(parent, baggageKey, s)
+}
+
+// ContextWithGetHook returns a copy of parent with hook configured to be
+// invoked every time FromContext is called.
+//
+// Passing nil GetHookFunc creates a context with no get hook to call.
+func ContextWithGetHook(parent context.Context, hook GetHookFunc) context.Context {
+	var s baggageState
+	switch v := parent.Value(baggageKey).(type) {
+	case baggageState:
+		s = v
+	}
+
+	s.getHook = hook
+	return context.WithValue(parent, baggageKey, s)
+}
+
+// ContextWithList returns a copy of parent with baggage. Passing nil list
+// returns a context without any baggage.
+func ContextWithList(parent context.Context, list List) context.Context {
+	var s baggageState
+	switch v := parent.Value(baggageKey).(type) {
+	case baggageState:
+		s = v
+	}
+
+	s.list = list
+	ctx := context.WithValue(parent, baggageKey, s)
+	if s.setHook != nil {
+		ctx = s.setHook(ctx, list)
+	}
+
+	return ctx
+}
+
+// ListFromContext returns the baggage contained in ctx.
+func ListFromContext(ctx context.Context) List {
+	switch v := ctx.Value(baggageKey).(type) {
+	case baggageState:
+		if v.getHook != nil {
+			return v.getHook(ctx, v.list)
+		}
+		return v.list
+	default:
+		return nil
+	}
+}

vendor/go.opentelemetry.io/otel/internal/global/internal_logging.go

@@ -0,0 +1,63 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package global // import "go.opentelemetry.io/otel/internal/global"
+
+import (
+	"log"
+	"os"
+	"sync"
+
+	"github.com/go-logr/logr"
+	"github.com/go-logr/stdr"
+)
+
+// globalLogger is the logging interface used within the otel api and sdk provide deatails of the internals.
+//
+// The default logger uses stdr which is backed by the standard `log.Logger`
+// interface. This logger will only show messages at the Error Level.
+var globalLogger logr.Logger = stdr.New(log.New(os.Stderr, "", log.LstdFlags|log.Lshortfile))
+var globalLoggerLock = &sync.RWMutex{}
+
+// SetLogger overrides the globalLogger with l.
+//
+// To see Info messages use a logger with `l.V(1).Enabled() == true`
+// To see Debug messages use a logger with `l.V(5).Enabled() == true`
+func SetLogger(l logr.Logger) {
+	globalLoggerLock.Lock()
+	defer globalLoggerLock.Unlock()
+	globalLogger = l
+}
+
+// Info prints messages about the general state of the API or SDK.
+// This should usually be less then 5 messages a minute
+func Info(msg string, keysAndValues ...interface{}) {
+	globalLoggerLock.RLock()
+	defer globalLoggerLock.RUnlock()
+	globalLogger.V(1).Info(msg, keysAndValues...)
+}
+
+// Error prints messages about exceptional states of the API or SDK.
+func Error(err error, msg string, keysAndValues ...interface{}) {
+	globalLoggerLock.RLock()
+	defer globalLoggerLock.RUnlock()
+	globalLogger.Error(err, msg, keysAndValues...)
+}
+
+// Debug prints messages about all internal changes in the API or SDK.
+func Debug(msg string, keysAndValues ...interface{}) {
+	globalLoggerLock.RLock()
+	defer globalLoggerLock.RUnlock()
+	globalLogger.V(5).Info(msg, keysAndValues...)
+}

vendor/go.opentelemetry.io/otel/internal/global/propagator.go

@@ -0,0 +1,82 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package global // import "go.opentelemetry.io/otel/internal/global"
+
+import (
+	"context"
+	"sync"
+
+	"go.opentelemetry.io/otel/propagation"
+)
+
+// textMapPropagator is a default TextMapPropagator that delegates calls to a
+// registered delegate if one is set, otherwise it defaults to delegating the
+// calls to a the default no-op propagation.TextMapPropagator.
+type textMapPropagator struct {
+	mtx      sync.Mutex
+	once     sync.Once
+	delegate propagation.TextMapPropagator
+	noop     propagation.TextMapPropagator
+}
+
+// Compile-time guarantee that textMapPropagator implements the
+// propagation.TextMapPropagator interface.
+var _ propagation.TextMapPropagator = (*textMapPropagator)(nil)
+
+func newTextMapPropagator() *textMapPropagator {
+	return &textMapPropagator{
+		noop: propagation.NewCompositeTextMapPropagator(),
+	}
+}
+
+// SetDelegate sets a delegate propagation.TextMapPropagator that all calls are
+// forwarded to. Delegation can only be performed once, all subsequent calls
+// perform no delegation.
+func (p *textMapPropagator) SetDelegate(delegate propagation.TextMapPropagator) {
+	if delegate == nil {
+		return
+	}
+
+	p.mtx.Lock()
+	p.once.Do(func() { p.delegate = delegate })
+	p.mtx.Unlock()
+}
+
+// effectiveDelegate returns the current delegate of p if one is set,
+// otherwise the default noop TextMapPropagator is returned. This method
+// can be called concurrently.
+func (p *textMapPropagator) effectiveDelegate() propagation.TextMapPropagator {
+	p.mtx.Lock()
+	defer p.mtx.Unlock()
+	if p.delegate != nil {
+		return p.delegate
+	}
+	return p.noop
+}
+
+// Inject set cross-cutting concerns from the Context into the carrier.
+func (p *textMapPropagator) Inject(ctx context.Context, carrier propagation.TextMapCarrier) {
+	p.effectiveDelegate().Inject(ctx, carrier)
+}
+
+// Extract reads cross-cutting concerns from the carrier into a Context.
+func (p *textMapPropagator) Extract(ctx context.Context, carrier propagation.TextMapCarrier) context.Context {
+	return p.effectiveDelegate().Extract(ctx, carrier)
+}
+
+// Fields returns the keys whose values are set with Inject.
+func (p *textMapPropagator) Fields() []string {
+	return p.effectiveDelegate().Fields()
+}

vendor/go.opentelemetry.io/otel/internal/global/state.go

@@ -0,0 +1,106 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package global // import "go.opentelemetry.io/otel/internal/global"
+
+import (
+	"sync"
+	"sync/atomic"
+
+	"go.opentelemetry.io/otel/propagation"
+	"go.opentelemetry.io/otel/trace"
+)
+
+type (
+	tracerProviderHolder struct {
+		tp trace.TracerProvider
+	}
+
+	propagatorsHolder struct {
+		tm propagation.TextMapPropagator
+	}
+)
+
+var (
+	globalTracer      = defaultTracerValue()
+	globalPropagators = defaultPropagatorsValue()
+
+	delegateTraceOnce             sync.Once
+	delegateTextMapPropagatorOnce sync.Once
+)
+
+// TracerProvider is the internal implementation for global.TracerProvider.
+func TracerProvider() trace.TracerProvider {
+	return globalTracer.Load().(tracerProviderHolder).tp
+}
+
+// SetTracerProvider is the internal implementation for global.SetTracerProvider.
+func SetTracerProvider(tp trace.TracerProvider) {
+	delegateTraceOnce.Do(func() {
+		current := TracerProvider()
+		if current == tp {
+			// Setting the provider to the prior default is nonsense, panic.
+			// Panic is acceptable because we are likely still early in the
+			// process lifetime.
+			panic("invalid TracerProvider, the global instance cannot be reinstalled")
+		} else if def, ok := current.(*tracerProvider); ok {
+			def.setDelegate(tp)
+		}
+
+	})
+	globalTracer.Store(tracerProviderHolder{tp: tp})
+}
+
+// TextMapPropagator is the internal implementation for global.TextMapPropagator.
+func TextMapPropagator() propagation.TextMapPropagator {
+	return globalPropagators.Load().(propagatorsHolder).tm
+}
+
+// SetTextMapPropagator is the internal implementation for global.SetTextMapPropagator.
+func SetTextMapPropagator(p propagation.TextMapPropagator) {
+	// For the textMapPropagator already returned by TextMapPropagator
+	// delegate to p.
+	delegateTextMapPropagatorOnce.Do(func() {
+		if current := TextMapPropagator(); current == p {
+			// Setting the provider to the prior default is nonsense, panic.
+			// Panic is acceptable because we are likely still early in the
+			// process lifetime.
+			panic("invalid TextMapPropagator, the global instance cannot be reinstalled")
+		} else if def, ok := current.(*textMapPropagator); ok {
+			def.SetDelegate(p)
+		}
+	})
+	// Return p when subsequent calls to TextMapPropagator are made.
+	globalPropagators.Store(propagatorsHolder{tm: p})
+}
+
+func defaultTracerValue() *atomic.Value {
+	v := &atomic.Value{}
+	v.Store(tracerProviderHolder{tp: &tracerProvider{}})
+	return v
+}
+
+func defaultPropagatorsValue() *atomic.Value {
+	v := &atomic.Value{}
+	v.Store(propagatorsHolder{tm: newTextMapPropagator()})
+	return v
+}
+
+// ResetForTest restores the initial global state, for testing purposes.
+func ResetForTest() {
+	globalTracer = defaultTracerValue()
+	globalPropagators = defaultPropagatorsValue()
+	delegateTraceOnce = sync.Once{}
+	delegateTextMapPropagatorOnce = sync.Once{}
+}

vendor/go.opentelemetry.io/otel/internal/global/trace.go

@@ -0,0 +1,192 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package global // import "go.opentelemetry.io/otel/internal/global"
+
+/*
+This file contains the forwarding implementation of the TracerProvider used as
+the default global instance. Prior to initialization of an SDK, Tracers
+returned by the global TracerProvider will provide no-op functionality. This
+means that all Span created prior to initialization are no-op Spans.
+
+Once an SDK has been initialized, all provided no-op Tracers are swapped for
+Tracers provided by the SDK defined TracerProvider. However, any Span started
+prior to this initialization does not change its behavior. Meaning, the Span
+remains a no-op Span.
+
+The implementation to track and swap Tracers locks all new Tracer creation
+until the swap is complete. This assumes that this operation is not
+performance-critical. If that assumption is incorrect, be sure to configure an
+SDK prior to any Tracer creation.
+*/
+
+import (
+	"context"
+	"sync"
+	"sync/atomic"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/codes"
+	"go.opentelemetry.io/otel/trace"
+)
+
+// tracerProvider is a placeholder for a configured SDK TracerProvider.
+//
+// All TracerProvider functionality is forwarded to a delegate once
+// configured.
+type tracerProvider struct {
+	mtx      sync.Mutex
+	tracers  map[il]*tracer
+	delegate trace.TracerProvider
+}
+
+// Compile-time guarantee that tracerProvider implements the TracerProvider
+// interface.
+var _ trace.TracerProvider = &tracerProvider{}
+
+// setDelegate configures p to delegate all TracerProvider functionality to
+// provider.
+//
+// All Tracers provided prior to this function call are switched out to be
+// Tracers provided by provider.
+//
+// It is guaranteed by the caller that this happens only once.
+func (p *tracerProvider) setDelegate(provider trace.TracerProvider) {
+	p.mtx.Lock()
+	defer p.mtx.Unlock()
+
+	p.delegate = provider
+
+	if len(p.tracers) == 0 {
+		return
+	}
+
+	for _, t := range p.tracers {
+		t.setDelegate(provider)
+	}
+
+	p.tracers = nil
+}
+
+// Tracer implements TracerProvider.
+func (p *tracerProvider) Tracer(name string, opts ...trace.TracerOption) trace.Tracer {
+	p.mtx.Lock()
+	defer p.mtx.Unlock()
+
+	if p.delegate != nil {
+		return p.delegate.Tracer(name, opts...)
+	}
+
+	// At this moment it is guaranteed that no sdk is installed, save the tracer in the tracers map.
+
+	c := trace.NewTracerConfig(opts...)
+	key := il{
+		name:    name,
+		version: c.InstrumentationVersion(),
+	}
+
+	if p.tracers == nil {
+		p.tracers = make(map[il]*tracer)
+	}
+
+	if val, ok := p.tracers[key]; ok {
+		return val
+	}
+
+	t := &tracer{name: name, opts: opts, provider: p}
+	p.tracers[key] = t
+	return t
+}
+
+type il struct {
+	name    string
+	version string
+}
+
+// tracer is a placeholder for a trace.Tracer.
+//
+// All Tracer functionality is forwarded to a delegate once configured.
+// Otherwise, all functionality is forwarded to a NoopTracer.
+type tracer struct {
+	name     string
+	opts     []trace.TracerOption
+	provider *tracerProvider
+
+	delegate atomic.Value
+}
+
+// Compile-time guarantee that tracer implements the trace.Tracer interface.
+var _ trace.Tracer = &tracer{}
+
+// setDelegate configures t to delegate all Tracer functionality to Tracers
+// created by provider.
+//
+// All subsequent calls to the Tracer methods will be passed to the delegate.
+//
+// It is guaranteed by the caller that this happens only once.
+func (t *tracer) setDelegate(provider trace.TracerProvider) {
+	t.delegate.Store(provider.Tracer(t.name, t.opts...))
+}
+
+// Start implements trace.Tracer by forwarding the call to t.delegate if
+// set, otherwise it forwards the call to a NoopTracer.
+func (t *tracer) Start(ctx context.Context, name string, opts ...trace.SpanStartOption) (context.Context, trace.Span) {
+	delegate := t.delegate.Load()
+	if delegate != nil {
+		return delegate.(trace.Tracer).Start(ctx, name, opts...)
+	}
+
+	s := nonRecordingSpan{sc: trace.SpanContextFromContext(ctx), tracer: t}
+	ctx = trace.ContextWithSpan(ctx, s)
+	return ctx, s
+}
+
+// nonRecordingSpan is a minimal implementation of a Span that wraps a
+// SpanContext. It performs no operations other than to return the wrapped
+// SpanContext.
+type nonRecordingSpan struct {
+	sc     trace.SpanContext
+	tracer *tracer
+}
+
+var _ trace.Span = nonRecordingSpan{}
+
+// SpanContext returns the wrapped SpanContext.
+func (s nonRecordingSpan) SpanContext() trace.SpanContext { return s.sc }
+
+// IsRecording always returns false.
+func (nonRecordingSpan) IsRecording() bool { return false }
+
+// SetStatus does nothing.
+func (nonRecordingSpan) SetStatus(codes.Code, string) {}
+
+// SetError does nothing.
+func (nonRecordingSpan) SetError(bool) {}
+
+// SetAttributes does nothing.
+func (nonRecordingSpan) SetAttributes(...attribute.KeyValue) {}
+
+// End does nothing.
+func (nonRecordingSpan) End(...trace.SpanEndOption) {}
+
+// RecordError does nothing.
+func (nonRecordingSpan) RecordError(error, ...trace.EventOption) {}
+
+// AddEvent does nothing.
+func (nonRecordingSpan) AddEvent(string, ...trace.EventOption) {}
+
+// SetName does nothing.
+func (nonRecordingSpan) SetName(string) {}
+
+func (s nonRecordingSpan) TracerProvider() trace.TracerProvider { return s.tracer.provider }

vendor/go.opentelemetry.io/otel/internal/metric/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
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+   limitations under the License.

vendor/go.opentelemetry.io/otel/internal/metric/global/meter.go

@@ -0,0 +1,287 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package global // import "go.opentelemetry.io/otel/internal/metric/global"
+
+import (
+	"context"
+	"sync"
+	"sync/atomic"
+	"unsafe"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/internal/metric/registry"
+	"go.opentelemetry.io/otel/metric"
+	"go.opentelemetry.io/otel/metric/number"
+	"go.opentelemetry.io/otel/metric/sdkapi"
+)
+
+// This file contains the forwarding implementation of MeterProvider used as
+// the default global instance.  Metric events using instruments provided by
+// this implementation are no-ops until the first Meter implementation is set
+// as the global provider.
+//
+// The implementation here uses Mutexes to maintain a list of active Meters in
+// the MeterProvider and Instruments in each Meter, under the assumption that
+// these interfaces are not performance-critical.
+//
+// We have the invariant that setDelegate() will be called before a new
+// MeterProvider implementation is registered as the global provider.  Mutexes
+// in the MeterProvider and Meters ensure that each instrument has a delegate
+// before the global provider is set.
+//
+// Metric uniqueness checking is implemented by calling the exported
+// methods of the api/metric/registry package.
+
+type meterKey struct {
+	InstrumentationName    string
+	InstrumentationVersion string
+	SchemaURL              string
+}
+
+type meterProvider struct {
+	delegate metric.MeterProvider
+
+	// lock protects `delegate` and `meters`.
+	lock sync.Mutex
+
+	// meters maintains a unique entry for every named Meter
+	// that has been registered through the global instance.
+	meters map[meterKey]*meterEntry
+}
+
+type meterImpl struct {
+	delegate unsafe.Pointer // (*metric.MeterImpl)
+
+	lock       sync.Mutex
+	syncInsts  []*syncImpl
+	asyncInsts []*asyncImpl
+}
+
+type meterEntry struct {
+	unique sdkapi.MeterImpl
+	impl   meterImpl
+}
+
+type instrument struct {
+	descriptor sdkapi.Descriptor
+}
+
+type syncImpl struct {
+	delegate unsafe.Pointer // (*sdkapi.SyncImpl)
+
+	instrument
+}
+
+type asyncImpl struct {
+	delegate unsafe.Pointer // (*sdkapi.AsyncImpl)
+
+	instrument
+
+	runner sdkapi.AsyncRunner
+}
+
+var _ metric.MeterProvider = &meterProvider{}
+var _ sdkapi.MeterImpl = &meterImpl{}
+var _ sdkapi.InstrumentImpl = &syncImpl{}
+var _ sdkapi.AsyncImpl = &asyncImpl{}
+
+func (inst *instrument) Descriptor() sdkapi.Descriptor {
+	return inst.descriptor
+}
+
+// MeterProvider interface and delegation
+
+func newMeterProvider() *meterProvider {
+	return &meterProvider{
+		meters: map[meterKey]*meterEntry{},
+	}
+}
+
+func (p *meterProvider) setDelegate(provider metric.MeterProvider) {
+	p.lock.Lock()
+	defer p.lock.Unlock()
+
+	p.delegate = provider
+	for key, entry := range p.meters {
+		entry.impl.setDelegate(key, provider)
+	}
+	p.meters = nil
+}
+
+func (p *meterProvider) Meter(instrumentationName string, opts ...metric.MeterOption) metric.Meter {
+	p.lock.Lock()
+	defer p.lock.Unlock()
+
+	if p.delegate != nil {
+		return p.delegate.Meter(instrumentationName, opts...)
+	}
+
+	cfg := metric.NewMeterConfig(opts...)
+	key := meterKey{
+		InstrumentationName:    instrumentationName,
+		InstrumentationVersion: cfg.InstrumentationVersion(),
+		SchemaURL:              cfg.SchemaURL(),
+	}
+	entry, ok := p.meters[key]
+	if !ok {
+		entry = &meterEntry{}
+		// Note: This code implements its own MeterProvider
+		// name-uniqueness logic because there is
+		// synchronization required at the moment of
+		// delegation.  We use the same instrument-uniqueness
+		// checking the real SDK uses here:
+		entry.unique = registry.NewUniqueInstrumentMeterImpl(&entry.impl)
+		p.meters[key] = entry
+	}
+	return metric.WrapMeterImpl(entry.unique)
+}
+
+// Meter interface and delegation
+
+func (m *meterImpl) setDelegate(key meterKey, provider metric.MeterProvider) {
+	m.lock.Lock()
+	defer m.lock.Unlock()
+
+	d := new(sdkapi.MeterImpl)
+	*d = provider.Meter(
+		key.InstrumentationName,
+		metric.WithInstrumentationVersion(key.InstrumentationVersion),
+		metric.WithSchemaURL(key.SchemaURL),
+	).MeterImpl()
+	m.delegate = unsafe.Pointer(d)
+
+	for _, inst := range m.syncInsts {
+		inst.setDelegate(*d)
+	}
+	m.syncInsts = nil
+	for _, obs := range m.asyncInsts {
+		obs.setDelegate(*d)
+	}
+	m.asyncInsts = nil
+}
+
+func (m *meterImpl) NewSyncInstrument(desc sdkapi.Descriptor) (sdkapi.SyncImpl, error) {
+	m.lock.Lock()
+	defer m.lock.Unlock()
+
+	if meterPtr := (*sdkapi.MeterImpl)(atomic.LoadPointer(&m.delegate)); meterPtr != nil {
+		return (*meterPtr).NewSyncInstrument(desc)
+	}
+
+	inst := &syncImpl{
+		instrument: instrument{
+			descriptor: desc,
+		},
+	}
+	m.syncInsts = append(m.syncInsts, inst)
+	return inst, nil
+}
+
+// Synchronous delegation
+
+func (inst *syncImpl) setDelegate(d sdkapi.MeterImpl) {
+	implPtr := new(sdkapi.SyncImpl)
+
+	var err error
+	*implPtr, err = d.NewSyncInstrument(inst.descriptor)
+
+	if err != nil {
+		// TODO: There is no standard way to deliver this error to the user.
+		// See https://github.com/open-telemetry/opentelemetry-go/issues/514
+		// Note that the default SDK will not generate any errors yet, this is
+		// only for added safety.
+		panic(err)
+	}
+
+	atomic.StorePointer(&inst.delegate, unsafe.Pointer(implPtr))
+}
+
+func (inst *syncImpl) Implementation() interface{} {
+	if implPtr := (*sdkapi.SyncImpl)(atomic.LoadPointer(&inst.delegate)); implPtr != nil {
+		return (*implPtr).Implementation()
+	}
+	return inst
+}
+
+// Async delegation
+
+func (m *meterImpl) NewAsyncInstrument(
+	desc sdkapi.Descriptor,
+	runner sdkapi.AsyncRunner,
+) (sdkapi.AsyncImpl, error) {
+
+	m.lock.Lock()
+	defer m.lock.Unlock()
+
+	if meterPtr := (*sdkapi.MeterImpl)(atomic.LoadPointer(&m.delegate)); meterPtr != nil {
+		return (*meterPtr).NewAsyncInstrument(desc, runner)
+	}
+
+	inst := &asyncImpl{
+		instrument: instrument{
+			descriptor: desc,
+		},
+		runner: runner,
+	}
+	m.asyncInsts = append(m.asyncInsts, inst)
+	return inst, nil
+}
+
+func (obs *asyncImpl) Implementation() interface{} {
+	if implPtr := (*sdkapi.AsyncImpl)(atomic.LoadPointer(&obs.delegate)); implPtr != nil {
+		return (*implPtr).Implementation()
+	}
+	return obs
+}
+
+func (obs *asyncImpl) setDelegate(d sdkapi.MeterImpl) {
+	implPtr := new(sdkapi.AsyncImpl)
+
+	var err error
+	*implPtr, err = d.NewAsyncInstrument(obs.descriptor, obs.runner)
+
+	if err != nil {
+		// TODO: There is no standard way to deliver this error to the user.
+		// See https://github.com/open-telemetry/opentelemetry-go/issues/514
+		// Note that the default SDK will not generate any errors yet, this is
+		// only for added safety.
+		panic(err)
+	}
+
+	atomic.StorePointer(&obs.delegate, unsafe.Pointer(implPtr))
+}
+
+// Metric updates
+
+func (m *meterImpl) RecordBatch(ctx context.Context, labels []attribute.KeyValue, measurements ...sdkapi.Measurement) {
+	if delegatePtr := (*sdkapi.MeterImpl)(atomic.LoadPointer(&m.delegate)); delegatePtr != nil {
+		(*delegatePtr).RecordBatch(ctx, labels, measurements...)
+	}
+}
+
+func (inst *syncImpl) RecordOne(ctx context.Context, number number.Number, labels []attribute.KeyValue) {
+	if instPtr := (*sdkapi.SyncImpl)(atomic.LoadPointer(&inst.delegate)); instPtr != nil {
+		(*instPtr).RecordOne(ctx, number, labels)
+	}
+}
+
+func AtomicFieldOffsets() map[string]uintptr {
+	return map[string]uintptr{
+		"meterProvider.delegate": unsafe.Offsetof(meterProvider{}.delegate),
+		"meterImpl.delegate":     unsafe.Offsetof(meterImpl{}.delegate),
+		"syncImpl.delegate":      unsafe.Offsetof(syncImpl{}.delegate),
+		"asyncImpl.delegate":     unsafe.Offsetof(asyncImpl{}.delegate),
+	}
+}

vendor/go.opentelemetry.io/otel/internal/metric/global/metric.go

@@ -0,0 +1,66 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package global // import "go.opentelemetry.io/otel/internal/metric/global"
+
+import (
+	"sync"
+	"sync/atomic"
+
+	"go.opentelemetry.io/otel/metric"
+)
+
+type meterProviderHolder struct {
+	mp metric.MeterProvider
+}
+
+var (
+	globalMeter = defaultMeterValue()
+
+	delegateMeterOnce sync.Once
+)
+
+// MeterProvider is the internal implementation for global.MeterProvider.
+func MeterProvider() metric.MeterProvider {
+	return globalMeter.Load().(meterProviderHolder).mp
+}
+
+// SetMeterProvider is the internal implementation for global.SetMeterProvider.
+func SetMeterProvider(mp metric.MeterProvider) {
+	delegateMeterOnce.Do(func() {
+		current := MeterProvider()
+
+		if current == mp {
+			// Setting the provider to the prior default is nonsense, panic.
+			// Panic is acceptable because we are likely still early in the
+			// process lifetime.
+			panic("invalid MeterProvider, the global instance cannot be reinstalled")
+		} else if def, ok := current.(*meterProvider); ok {
+			def.setDelegate(mp)
+		}
+	})
+	globalMeter.Store(meterProviderHolder{mp: mp})
+}
+
+func defaultMeterValue() *atomic.Value {
+	v := &atomic.Value{}
+	v.Store(meterProviderHolder{mp: newMeterProvider()})
+	return v
+}
+
+// ResetForTest restores the initial global state, for testing purposes.
+func ResetForTest() {
+	globalMeter = defaultMeterValue()
+	delegateMeterOnce = sync.Once{}
+}

vendor/go.opentelemetry.io/otel/internal/metric/registry/doc.go

@@ -0,0 +1,24 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/*
+Package registry provides a non-standalone implementation of
+MeterProvider that adds uniqueness checking for instrument descriptors
+on top of other MeterProvider it wraps.
+
+This package is currently in a pre-GA phase. Backwards incompatible changes
+may be introduced in subsequent minor version releases as we work to track the
+evolving OpenTelemetry specification and user feedback.
+*/
+package registry // import "go.opentelemetry.io/otel/internal/metric/registry"

vendor/go.opentelemetry.io/otel/internal/metric/registry/registry.go

@@ -0,0 +1,139 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package registry // import "go.opentelemetry.io/otel/internal/metric/registry"
+
+import (
+	"context"
+	"fmt"
+	"sync"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric/sdkapi"
+)
+
+// UniqueInstrumentMeterImpl implements the metric.MeterImpl interface, adding
+// uniqueness checking for instrument descriptors.
+type UniqueInstrumentMeterImpl struct {
+	lock  sync.Mutex
+	impl  sdkapi.MeterImpl
+	state map[string]sdkapi.InstrumentImpl
+}
+
+var _ sdkapi.MeterImpl = (*UniqueInstrumentMeterImpl)(nil)
+
+// ErrMetricKindMismatch is the standard error for mismatched metric
+// instrument definitions.
+var ErrMetricKindMismatch = fmt.Errorf(
+	"a metric was already registered by this name with another kind or number type")
+
+// NewUniqueInstrumentMeterImpl returns a wrapped metric.MeterImpl
+// with the addition of instrument name uniqueness checking.
+func NewUniqueInstrumentMeterImpl(impl sdkapi.MeterImpl) *UniqueInstrumentMeterImpl {
+	return &UniqueInstrumentMeterImpl{
+		impl:  impl,
+		state: map[string]sdkapi.InstrumentImpl{},
+	}
+}
+
+// MeterImpl gives the caller access to the underlying MeterImpl
+// used by this UniqueInstrumentMeterImpl.
+func (u *UniqueInstrumentMeterImpl) MeterImpl() sdkapi.MeterImpl {
+	return u.impl
+}
+
+// RecordBatch implements sdkapi.MeterImpl.
+func (u *UniqueInstrumentMeterImpl) RecordBatch(ctx context.Context, labels []attribute.KeyValue, ms ...sdkapi.Measurement) {
+	u.impl.RecordBatch(ctx, labels, ms...)
+}
+
+// NewMetricKindMismatchError formats an error that describes a
+// mismatched metric instrument definition.
+func NewMetricKindMismatchError(desc sdkapi.Descriptor) error {
+	return fmt.Errorf("metric %s registered as %s %s: %w",
+		desc.Name(),
+		desc.NumberKind(),
+		desc.InstrumentKind(),
+		ErrMetricKindMismatch)
+}
+
+// Compatible determines whether two sdkapi.Descriptors are considered
+// the same for the purpose of uniqueness checking.
+func Compatible(candidate, existing sdkapi.Descriptor) bool {
+	return candidate.InstrumentKind() == existing.InstrumentKind() &&
+		candidate.NumberKind() == existing.NumberKind()
+}
+
+// checkUniqueness returns an ErrMetricKindMismatch error if there is
+// a conflict between a descriptor that was already registered and the
+// `descriptor` argument.  If there is an existing compatible
+// registration, this returns the already-registered instrument.  If
+// there is no conflict and no prior registration, returns (nil, nil).
+func (u *UniqueInstrumentMeterImpl) checkUniqueness(descriptor sdkapi.Descriptor) (sdkapi.InstrumentImpl, error) {
+	impl, ok := u.state[descriptor.Name()]
+	if !ok {
+		return nil, nil
+	}
+
+	if !Compatible(descriptor, impl.Descriptor()) {
+		return nil, NewMetricKindMismatchError(impl.Descriptor())
+	}
+
+	return impl, nil
+}
+
+// NewSyncInstrument implements sdkapi.MeterImpl.
+func (u *UniqueInstrumentMeterImpl) NewSyncInstrument(descriptor sdkapi.Descriptor) (sdkapi.SyncImpl, error) {
+	u.lock.Lock()
+	defer u.lock.Unlock()
+
+	impl, err := u.checkUniqueness(descriptor)
+
+	if err != nil {
+		return nil, err
+	} else if impl != nil {
+		return impl.(sdkapi.SyncImpl), nil
+	}
+
+	syncInst, err := u.impl.NewSyncInstrument(descriptor)
+	if err != nil {
+		return nil, err
+	}
+	u.state[descriptor.Name()] = syncInst
+	return syncInst, nil
+}
+
+// NewAsyncInstrument implements sdkapi.MeterImpl.
+func (u *UniqueInstrumentMeterImpl) NewAsyncInstrument(
+	descriptor sdkapi.Descriptor,
+	runner sdkapi.AsyncRunner,
+) (sdkapi.AsyncImpl, error) {
+	u.lock.Lock()
+	defer u.lock.Unlock()
+
+	impl, err := u.checkUniqueness(descriptor)
+
+	if err != nil {
+		return nil, err
+	} else if impl != nil {
+		return impl.(sdkapi.AsyncImpl), nil
+	}
+
+	asyncInst, err := u.impl.NewAsyncInstrument(descriptor, runner)
+	if err != nil {
+		return nil, err
+	}
+	u.state[descriptor.Name()] = asyncInst
+	return asyncInst, nil
+}

vendor/go.opentelemetry.io/otel/internal/rawhelpers.go

@@ -0,0 +1,55 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package internal // import "go.opentelemetry.io/otel/internal"
+
+import (
+	"math"
+	"unsafe"
+)
+
+func BoolToRaw(b bool) uint64 {
+	if b {
+		return 1
+	}
+	return 0
+}
+
+func RawToBool(r uint64) bool {
+	return r != 0
+}
+
+func Int64ToRaw(i int64) uint64 {
+	return uint64(i)
+}
+
+func RawToInt64(r uint64) int64 {
+	return int64(r)
+}
+
+func Float64ToRaw(f float64) uint64 {
+	return math.Float64bits(f)
+}
+
+func RawToFloat64(r uint64) float64 {
+	return math.Float64frombits(r)
+}
+
+func RawPtrToFloat64Ptr(r *uint64) *float64 {
+	return (*float64)(unsafe.Pointer(r))
+}
+
+func RawPtrToInt64Ptr(r *uint64) *int64 {
+	return (*int64)(unsafe.Pointer(r))
+}

vendor/go.opentelemetry.io/otel/internal_logging.go

@@ -0,0 +1,26 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package otel // import "go.opentelemetry.io/otel"
+
+import (
+	"github.com/go-logr/logr"
+
+	"go.opentelemetry.io/otel/internal/global"
+)
+
+// SetLogger configures the logger used internally to opentelemetry.
+func SetLogger(logger logr.Logger) {
+	global.SetLogger(logger)
+}

vendor/go.opentelemetry.io/otel/metric/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
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+
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+      other entities that control, are controlled by, or are under common
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+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
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+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
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+      of this License, Derivative Works shall not include works that remain
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+      "Contribution" shall mean any work of authorship, including
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+      You may add Your own copyright statement to Your modifications and
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+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
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+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
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+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
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+      on Your own behalf and on Your sole responsibility, not on behalf
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+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
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+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/go.opentelemetry.io/otel/metric/config.go

@@ -0,0 +1,128 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package metric // import "go.opentelemetry.io/otel/metric"
+
+import (
+	"go.opentelemetry.io/otel/metric/unit"
+)
+
+// InstrumentConfig contains options for metric instrument descriptors.
+type InstrumentConfig struct {
+	description string
+	unit        unit.Unit
+}
+
+// Description describes the instrument in human-readable terms.
+func (cfg *InstrumentConfig) Description() string {
+	return cfg.description
+}
+
+// Unit describes the measurement unit for a instrument.
+func (cfg *InstrumentConfig) Unit() unit.Unit {
+	return cfg.unit
+}
+
+// InstrumentOption is an interface for applying metric instrument options.
+type InstrumentOption interface {
+	// ApplyMeter is used to set a InstrumentOption value of a
+	// InstrumentConfig.
+	applyInstrument(InstrumentConfig) InstrumentConfig
+}
+
+// NewInstrumentConfig creates a new InstrumentConfig
+// and applies all the given options.
+func NewInstrumentConfig(opts ...InstrumentOption) InstrumentConfig {
+	var config InstrumentConfig
+	for _, o := range opts {
+		config = o.applyInstrument(config)
+	}
+	return config
+}
+
+type instrumentOptionFunc func(InstrumentConfig) InstrumentConfig
+
+func (fn instrumentOptionFunc) applyInstrument(cfg InstrumentConfig) InstrumentConfig {
+	return fn(cfg)
+}
+
+// WithDescription applies provided description.
+func WithDescription(desc string) InstrumentOption {
+	return instrumentOptionFunc(func(cfg InstrumentConfig) InstrumentConfig {
+		cfg.description = desc
+		return cfg
+	})
+}
+
+// WithUnit applies provided unit.
+func WithUnit(unit unit.Unit) InstrumentOption {
+	return instrumentOptionFunc(func(cfg InstrumentConfig) InstrumentConfig {
+		cfg.unit = unit
+		return cfg
+	})
+}
+
+// MeterConfig contains options for Meters.
+type MeterConfig struct {
+	instrumentationVersion string
+	schemaURL              string
+}
+
+// InstrumentationVersion is the version of the library providing instrumentation.
+func (cfg *MeterConfig) InstrumentationVersion() string {
+	return cfg.instrumentationVersion
+}
+
+// SchemaURL is the schema_url of the library providing instrumentation.
+func (cfg *MeterConfig) SchemaURL() string {
+	return cfg.schemaURL
+}
+
+// MeterOption is an interface for applying Meter options.
+type MeterOption interface {
+	// ApplyMeter is used to set a MeterOption value of a MeterConfig.
+	applyMeter(MeterConfig) MeterConfig
+}
+
+// NewMeterConfig creates a new MeterConfig and applies
+// all the given options.
+func NewMeterConfig(opts ...MeterOption) MeterConfig {
+	var config MeterConfig
+	for _, o := range opts {
+		config = o.applyMeter(config)
+	}
+	return config
+}
+
+type meterOptionFunc func(MeterConfig) MeterConfig
+
+func (fn meterOptionFunc) applyMeter(cfg MeterConfig) MeterConfig {
+	return fn(cfg)
+}
+
+// WithInstrumentationVersion sets the instrumentation version.
+func WithInstrumentationVersion(version string) MeterOption {
+	return meterOptionFunc(func(config MeterConfig) MeterConfig {
+		config.instrumentationVersion = version
+		return config
+	})
+}
+
+// WithSchemaURL sets the schema URL.
+func WithSchemaURL(schemaURL string) MeterOption {
+	return meterOptionFunc(func(config MeterConfig) MeterConfig {
+		config.schemaURL = schemaURL
+		return config
+	})
+}

vendor/go.opentelemetry.io/otel/metric/doc.go

@@ -0,0 +1,67 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/*
+Package metric provides an implementation of the metrics part of the
+OpenTelemetry API.
+
+This package is currently in a pre-GA phase. Backwards incompatible changes
+may be introduced in subsequent minor version releases as we work to track the
+evolving OpenTelemetry specification and user feedback.
+
+Measurements can be made about an operation being performed or the state of a
+system in general. These measurements can be crucial to the reliable operation
+of code and provide valuable insights about the inner workings of a system.
+
+Measurements are made using instruments provided by this package. The type of
+instrument used will depend on the type of measurement being made and of what
+part of a system is being measured.
+
+Instruments are categorized as Synchronous or Asynchronous and independently
+as Adding or Grouping. Synchronous instruments are called by the user with a
+Context. Asynchronous instruments are called by the SDK during collection.
+Adding instruments are semantically intended for capturing a sum. Grouping
+instruments are intended for capturing a distribution.
+
+Adding instruments may be monotonic, in which case they are non-decreasing
+and naturally define a rate.
+
+The synchronous instrument names are:
+
+  Counter:           adding, monotonic
+  UpDownCounter:     adding
+  Histogram:         grouping
+
+and the asynchronous instruments are:
+
+  CounterObserver:       adding, monotonic
+  UpDownCounterObserver: adding
+  GaugeObserver:         grouping
+
+All instruments are provided with support for either float64 or int64 input
+values.
+
+An instrument is created using a Meter. Additionally, a Meter is used to
+record batches of synchronous measurements or asynchronous observations. A
+Meter is obtained using a MeterProvider. A Meter, like a Tracer, is unique to
+the instrumentation it instruments and must be named and versioned when
+created with a MeterProvider with the name and version of the instrumentation
+library.
+
+Instrumentation should be designed to accept a MeterProvider from which it can
+create its own unique Meter. Alternatively, the registered global
+MeterProvider from the go.opentelemetry.io/otel package can be used as a
+default.
+*/
+package metric // import "go.opentelemetry.io/otel/metric"

vendor/go.opentelemetry.io/otel/metric/global/metric.go

@@ -0,0 +1,49 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package global // import "go.opentelemetry.io/otel/metric/global"
+
+import (
+	"go.opentelemetry.io/otel/internal/metric/global"
+	"go.opentelemetry.io/otel/metric"
+)
+
+// Meter creates an implementation of the Meter interface from the global
+// MeterProvider. The instrumentationName must be the name of the library
+// providing instrumentation. This name may be the same as the instrumented
+// code only if that code provides built-in instrumentation. If the
+// instrumentationName is empty, then a implementation defined default name
+// will be used instead.
+//
+// This is short for MeterProvider().Meter(name)
+func Meter(instrumentationName string, opts ...metric.MeterOption) metric.Meter {
+	return GetMeterProvider().Meter(instrumentationName, opts...)
+}
+
+// GetMeterProvider returns the registered global meter provider.  If
+// none is registered then a default meter provider is returned that
+// forwards the Meter interface to the first registered Meter.
+//
+// Use the meter provider to create a named meter. E.g.
+//     meter := global.MeterProvider().Meter("example.com/foo")
+// or
+//     meter := global.Meter("example.com/foo")
+func GetMeterProvider() metric.MeterProvider {
+	return global.MeterProvider()
+}
+
+// SetMeterProvider registers `mp` as the global meter provider.
+func SetMeterProvider(mp metric.MeterProvider) {
+	global.SetMeterProvider(mp)
+}

vendor/go.opentelemetry.io/otel/metric/metric.go

@@ -0,0 +1,538 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package metric // import "go.opentelemetry.io/otel/metric"
+
+import (
+	"context"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric/number"
+	"go.opentelemetry.io/otel/metric/sdkapi"
+)
+
+// MeterProvider supports named Meter instances.
+type MeterProvider interface {
+	// Meter creates an implementation of the Meter interface.
+	// The instrumentationName must be the name of the library providing
+	// instrumentation. This name may be the same as the instrumented code
+	// only if that code provides built-in instrumentation. If the
+	// instrumentationName is empty, then a implementation defined default
+	// name will be used instead.
+	Meter(instrumentationName string, opts ...MeterOption) Meter
+}
+
+// Meter is the creator of metric instruments.
+//
+// An uninitialized Meter is a no-op implementation.
+type Meter struct {
+	impl sdkapi.MeterImpl
+}
+
+// WrapMeterImpl constructs a `Meter` implementation from a
+// `MeterImpl` implementation.
+func WrapMeterImpl(impl sdkapi.MeterImpl) Meter {
+	return Meter{
+		impl: impl,
+	}
+}
+
+// Measurement is used for reporting a synchronous batch of metric
+// values. Instances of this type should be created by synchronous
+// instruments (e.g., Int64Counter.Measurement()).
+//
+// Note: This is an alias because it is a first-class member of the
+// API but is also part of the lower-level sdkapi interface.
+type Measurement = sdkapi.Measurement
+
+// Observation is used for reporting an asynchronous  batch of metric
+// values. Instances of this type should be created by asynchronous
+// instruments (e.g., Int64GaugeObserver.Observation()).
+//
+// Note: This is an alias because it is a first-class member of the
+// API but is also part of the lower-level sdkapi interface.
+type Observation = sdkapi.Observation
+
+// RecordBatch atomically records a batch of measurements.
+func (m Meter) RecordBatch(ctx context.Context, ls []attribute.KeyValue, ms ...Measurement) {
+	if m.impl == nil {
+		return
+	}
+	m.impl.RecordBatch(ctx, ls, ms...)
+}
+
+// NewBatchObserver creates a new BatchObserver that supports
+// making batches of observations for multiple instruments.
+func (m Meter) NewBatchObserver(callback BatchObserverFunc) BatchObserver {
+	return BatchObserver{
+		meter:  m,
+		runner: newBatchAsyncRunner(callback),
+	}
+}
+
+// NewInt64Counter creates a new integer Counter instrument with the
+// given name, customized with options.  May return an error if the
+// name is invalid (e.g., empty) or improperly registered (e.g.,
+// duplicate registration).
+func (m Meter) NewInt64Counter(name string, options ...InstrumentOption) (Int64Counter, error) {
+	return wrapInt64CounterInstrument(
+		m.newSync(name, sdkapi.CounterInstrumentKind, number.Int64Kind, options))
+}
+
+// NewFloat64Counter creates a new floating point Counter with the
+// given name, customized with options.  May return an error if the
+// name is invalid (e.g., empty) or improperly registered (e.g.,
+// duplicate registration).
+func (m Meter) NewFloat64Counter(name string, options ...InstrumentOption) (Float64Counter, error) {
+	return wrapFloat64CounterInstrument(
+		m.newSync(name, sdkapi.CounterInstrumentKind, number.Float64Kind, options))
+}
+
+// NewInt64UpDownCounter creates a new integer UpDownCounter instrument with the
+// given name, customized with options.  May return an error if the
+// name is invalid (e.g., empty) or improperly registered (e.g.,
+// duplicate registration).
+func (m Meter) NewInt64UpDownCounter(name string, options ...InstrumentOption) (Int64UpDownCounter, error) {
+	return wrapInt64UpDownCounterInstrument(
+		m.newSync(name, sdkapi.UpDownCounterInstrumentKind, number.Int64Kind, options))
+}
+
+// NewFloat64UpDownCounter creates a new floating point UpDownCounter with the
+// given name, customized with options.  May return an error if the
+// name is invalid (e.g., empty) or improperly registered (e.g.,
+// duplicate registration).
+func (m Meter) NewFloat64UpDownCounter(name string, options ...InstrumentOption) (Float64UpDownCounter, error) {
+	return wrapFloat64UpDownCounterInstrument(
+		m.newSync(name, sdkapi.UpDownCounterInstrumentKind, number.Float64Kind, options))
+}
+
+// NewInt64Histogram creates a new integer Histogram instrument with the
+// given name, customized with options.  May return an error if the
+// name is invalid (e.g., empty) or improperly registered (e.g.,
+// duplicate registration).
+func (m Meter) NewInt64Histogram(name string, opts ...InstrumentOption) (Int64Histogram, error) {
+	return wrapInt64HistogramInstrument(
+		m.newSync(name, sdkapi.HistogramInstrumentKind, number.Int64Kind, opts))
+}
+
+// NewFloat64Histogram creates a new floating point Histogram with the
+// given name, customized with options.  May return an error if the
+// name is invalid (e.g., empty) or improperly registered (e.g.,
+// duplicate registration).
+func (m Meter) NewFloat64Histogram(name string, opts ...InstrumentOption) (Float64Histogram, error) {
+	return wrapFloat64HistogramInstrument(
+		m.newSync(name, sdkapi.HistogramInstrumentKind, number.Float64Kind, opts))
+}
+
+// NewInt64GaugeObserver creates a new integer GaugeObserver instrument
+// with the given name, running a given callback, and customized with
+// options.  May return an error if the name is invalid (e.g., empty)
+// or improperly registered (e.g., duplicate registration).
+func (m Meter) NewInt64GaugeObserver(name string, callback Int64ObserverFunc, opts ...InstrumentOption) (Int64GaugeObserver, error) {
+	if callback == nil {
+		return wrapInt64GaugeObserverInstrument(sdkapi.NewNoopAsyncInstrument(), nil)
+	}
+	return wrapInt64GaugeObserverInstrument(
+		m.newAsync(name, sdkapi.GaugeObserverInstrumentKind, number.Int64Kind, opts,
+			newInt64AsyncRunner(callback)))
+}
+
+// NewFloat64GaugeObserver creates a new floating point GaugeObserver with
+// the given name, running a given callback, and customized with
+// options.  May return an error if the name is invalid (e.g., empty)
+// or improperly registered (e.g., duplicate registration).
+func (m Meter) NewFloat64GaugeObserver(name string, callback Float64ObserverFunc, opts ...InstrumentOption) (Float64GaugeObserver, error) {
+	if callback == nil {
+		return wrapFloat64GaugeObserverInstrument(sdkapi.NewNoopAsyncInstrument(), nil)
+	}
+	return wrapFloat64GaugeObserverInstrument(
+		m.newAsync(name, sdkapi.GaugeObserverInstrumentKind, number.Float64Kind, opts,
+			newFloat64AsyncRunner(callback)))
+}
+
+// NewInt64CounterObserver creates a new integer CounterObserver instrument
+// with the given name, running a given callback, and customized with
+// options.  May return an error if the name is invalid (e.g., empty)
+// or improperly registered (e.g., duplicate registration).
+func (m Meter) NewInt64CounterObserver(name string, callback Int64ObserverFunc, opts ...InstrumentOption) (Int64CounterObserver, error) {
+	if callback == nil {
+		return wrapInt64CounterObserverInstrument(sdkapi.NewNoopAsyncInstrument(), nil)
+	}
+	return wrapInt64CounterObserverInstrument(
+		m.newAsync(name, sdkapi.CounterObserverInstrumentKind, number.Int64Kind, opts,
+			newInt64AsyncRunner(callback)))
+}
+
+// NewFloat64CounterObserver creates a new floating point CounterObserver with
+// the given name, running a given callback, and customized with
+// options.  May return an error if the name is invalid (e.g., empty)
+// or improperly registered (e.g., duplicate registration).
+func (m Meter) NewFloat64CounterObserver(name string, callback Float64ObserverFunc, opts ...InstrumentOption) (Float64CounterObserver, error) {
+	if callback == nil {
+		return wrapFloat64CounterObserverInstrument(sdkapi.NewNoopAsyncInstrument(), nil)
+	}
+	return wrapFloat64CounterObserverInstrument(
+		m.newAsync(name, sdkapi.CounterObserverInstrumentKind, number.Float64Kind, opts,
+			newFloat64AsyncRunner(callback)))
+}
+
+// NewInt64UpDownCounterObserver creates a new integer UpDownCounterObserver instrument
+// with the given name, running a given callback, and customized with
+// options.  May return an error if the name is invalid (e.g., empty)
+// or improperly registered (e.g., duplicate registration).
+func (m Meter) NewInt64UpDownCounterObserver(name string, callback Int64ObserverFunc, opts ...InstrumentOption) (Int64UpDownCounterObserver, error) {
+	if callback == nil {
+		return wrapInt64UpDownCounterObserverInstrument(sdkapi.NewNoopAsyncInstrument(), nil)
+	}
+	return wrapInt64UpDownCounterObserverInstrument(
+		m.newAsync(name, sdkapi.UpDownCounterObserverInstrumentKind, number.Int64Kind, opts,
+			newInt64AsyncRunner(callback)))
+}
+
+// NewFloat64UpDownCounterObserver creates a new floating point UpDownCounterObserver with
+// the given name, running a given callback, and customized with
+// options.  May return an error if the name is invalid (e.g., empty)
+// or improperly registered (e.g., duplicate registration).
+func (m Meter) NewFloat64UpDownCounterObserver(name string, callback Float64ObserverFunc, opts ...InstrumentOption) (Float64UpDownCounterObserver, error) {
+	if callback == nil {
+		return wrapFloat64UpDownCounterObserverInstrument(sdkapi.NewNoopAsyncInstrument(), nil)
+	}
+	return wrapFloat64UpDownCounterObserverInstrument(
+		m.newAsync(name, sdkapi.UpDownCounterObserverInstrumentKind, number.Float64Kind, opts,
+			newFloat64AsyncRunner(callback)))
+}
+
+// NewInt64GaugeObserver creates a new integer GaugeObserver instrument
+// with the given name, running in a batch callback, and customized with
+// options.  May return an error if the name is invalid (e.g., empty)
+// or improperly registered (e.g., duplicate registration).
+func (b BatchObserver) NewInt64GaugeObserver(name string, opts ...InstrumentOption) (Int64GaugeObserver, error) {
+	if b.runner == nil {
+		return wrapInt64GaugeObserverInstrument(sdkapi.NewNoopAsyncInstrument(), nil)
+	}
+	return wrapInt64GaugeObserverInstrument(
+		b.meter.newAsync(name, sdkapi.GaugeObserverInstrumentKind, number.Int64Kind, opts, b.runner))
+}
+
+// NewFloat64GaugeObserver creates a new floating point GaugeObserver with
+// the given name, running in a batch callback, and customized with
+// options.  May return an error if the name is invalid (e.g., empty)
+// or improperly registered (e.g., duplicate registration).
+func (b BatchObserver) NewFloat64GaugeObserver(name string, opts ...InstrumentOption) (Float64GaugeObserver, error) {
+	if b.runner == nil {
+		return wrapFloat64GaugeObserverInstrument(sdkapi.NewNoopAsyncInstrument(), nil)
+	}
+	return wrapFloat64GaugeObserverInstrument(
+		b.meter.newAsync(name, sdkapi.GaugeObserverInstrumentKind, number.Float64Kind, opts,
+			b.runner))
+}
+
+// NewInt64CounterObserver creates a new integer CounterObserver instrument
+// with the given name, running in a batch callback, and customized with
+// options.  May return an error if the name is invalid (e.g., empty)
+// or improperly registered (e.g., duplicate registration).
+func (b BatchObserver) NewInt64CounterObserver(name string, opts ...InstrumentOption) (Int64CounterObserver, error) {
+	if b.runner == nil {
+		return wrapInt64CounterObserverInstrument(sdkapi.NewNoopAsyncInstrument(), nil)
+	}
+	return wrapInt64CounterObserverInstrument(
+		b.meter.newAsync(name, sdkapi.CounterObserverInstrumentKind, number.Int64Kind, opts, b.runner))
+}
+
+// NewFloat64CounterObserver creates a new floating point CounterObserver with
+// the given name, running in a batch callback, and customized with
+// options.  May return an error if the name is invalid (e.g., empty)
+// or improperly registered (e.g., duplicate registration).
+func (b BatchObserver) NewFloat64CounterObserver(name string, opts ...InstrumentOption) (Float64CounterObserver, error) {
+	if b.runner == nil {
+		return wrapFloat64CounterObserverInstrument(sdkapi.NewNoopAsyncInstrument(), nil)
+	}
+	return wrapFloat64CounterObserverInstrument(
+		b.meter.newAsync(name, sdkapi.CounterObserverInstrumentKind, number.Float64Kind, opts,
+			b.runner))
+}
+
+// NewInt64UpDownCounterObserver creates a new integer UpDownCounterObserver instrument
+// with the given name, running in a batch callback, and customized with
+// options.  May return an error if the name is invalid (e.g., empty)
+// or improperly registered (e.g., duplicate registration).
+func (b BatchObserver) NewInt64UpDownCounterObserver(name string, opts ...InstrumentOption) (Int64UpDownCounterObserver, error) {
+	if b.runner == nil {
+		return wrapInt64UpDownCounterObserverInstrument(sdkapi.NewNoopAsyncInstrument(), nil)
+	}
+	return wrapInt64UpDownCounterObserverInstrument(
+		b.meter.newAsync(name, sdkapi.UpDownCounterObserverInstrumentKind, number.Int64Kind, opts, b.runner))
+}
+
+// NewFloat64UpDownCounterObserver creates a new floating point UpDownCounterObserver with
+// the given name, running in a batch callback, and customized with
+// options.  May return an error if the name is invalid (e.g., empty)
+// or improperly registered (e.g., duplicate registration).
+func (b BatchObserver) NewFloat64UpDownCounterObserver(name string, opts ...InstrumentOption) (Float64UpDownCounterObserver, error) {
+	if b.runner == nil {
+		return wrapFloat64UpDownCounterObserverInstrument(sdkapi.NewNoopAsyncInstrument(), nil)
+	}
+	return wrapFloat64UpDownCounterObserverInstrument(
+		b.meter.newAsync(name, sdkapi.UpDownCounterObserverInstrumentKind, number.Float64Kind, opts,
+			b.runner))
+}
+
+// MeterImpl returns the underlying MeterImpl of this Meter.
+func (m Meter) MeterImpl() sdkapi.MeterImpl {
+	return m.impl
+}
+
+// newAsync constructs one new asynchronous instrument.
+func (m Meter) newAsync(
+	name string,
+	mkind sdkapi.InstrumentKind,
+	nkind number.Kind,
+	opts []InstrumentOption,
+	runner sdkapi.AsyncRunner,
+) (
+	sdkapi.AsyncImpl,
+	error,
+) {
+	if m.impl == nil {
+		return sdkapi.NewNoopAsyncInstrument(), nil
+	}
+	cfg := NewInstrumentConfig(opts...)
+	desc := sdkapi.NewDescriptor(name, mkind, nkind, cfg.description, cfg.unit)
+	return m.impl.NewAsyncInstrument(desc, runner)
+}
+
+// newSync constructs one new synchronous instrument.
+func (m Meter) newSync(
+	name string,
+	metricKind sdkapi.InstrumentKind,
+	numberKind number.Kind,
+	opts []InstrumentOption,
+) (
+	sdkapi.SyncImpl,
+	error,
+) {
+	if m.impl == nil {
+		return sdkapi.NewNoopSyncInstrument(), nil
+	}
+	cfg := NewInstrumentConfig(opts...)
+	desc := sdkapi.NewDescriptor(name, metricKind, numberKind, cfg.description, cfg.unit)
+	return m.impl.NewSyncInstrument(desc)
+}
+
+// MeterMust is a wrapper for Meter interfaces that panics when any
+// instrument constructor encounters an error.
+type MeterMust struct {
+	meter Meter
+}
+
+// BatchObserverMust is a wrapper for BatchObserver that panics when
+// any instrument constructor encounters an error.
+type BatchObserverMust struct {
+	batch BatchObserver
+}
+
+// Must constructs a MeterMust implementation from a Meter, allowing
+// the application to panic when any instrument constructor yields an
+// error.
+func Must(meter Meter) MeterMust {
+	return MeterMust{meter: meter}
+}
+
+// NewInt64Counter calls `Meter.NewInt64Counter` and returns the
+// instrument, panicking if it encounters an error.
+func (mm MeterMust) NewInt64Counter(name string, cos ...InstrumentOption) Int64Counter {
+	if inst, err := mm.meter.NewInt64Counter(name, cos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewFloat64Counter calls `Meter.NewFloat64Counter` and returns the
+// instrument, panicking if it encounters an error.
+func (mm MeterMust) NewFloat64Counter(name string, cos ...InstrumentOption) Float64Counter {
+	if inst, err := mm.meter.NewFloat64Counter(name, cos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewInt64UpDownCounter calls `Meter.NewInt64UpDownCounter` and returns the
+// instrument, panicking if it encounters an error.
+func (mm MeterMust) NewInt64UpDownCounter(name string, cos ...InstrumentOption) Int64UpDownCounter {
+	if inst, err := mm.meter.NewInt64UpDownCounter(name, cos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewFloat64UpDownCounter calls `Meter.NewFloat64UpDownCounter` and returns the
+// instrument, panicking if it encounters an error.
+func (mm MeterMust) NewFloat64UpDownCounter(name string, cos ...InstrumentOption) Float64UpDownCounter {
+	if inst, err := mm.meter.NewFloat64UpDownCounter(name, cos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewInt64Histogram calls `Meter.NewInt64Histogram` and returns the
+// instrument, panicking if it encounters an error.
+func (mm MeterMust) NewInt64Histogram(name string, mos ...InstrumentOption) Int64Histogram {
+	if inst, err := mm.meter.NewInt64Histogram(name, mos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewFloat64Histogram calls `Meter.NewFloat64Histogram` and returns the
+// instrument, panicking if it encounters an error.
+func (mm MeterMust) NewFloat64Histogram(name string, mos ...InstrumentOption) Float64Histogram {
+	if inst, err := mm.meter.NewFloat64Histogram(name, mos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewInt64GaugeObserver calls `Meter.NewInt64GaugeObserver` and
+// returns the instrument, panicking if it encounters an error.
+func (mm MeterMust) NewInt64GaugeObserver(name string, callback Int64ObserverFunc, oos ...InstrumentOption) Int64GaugeObserver {
+	if inst, err := mm.meter.NewInt64GaugeObserver(name, callback, oos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewFloat64GaugeObserver calls `Meter.NewFloat64GaugeObserver` and
+// returns the instrument, panicking if it encounters an error.
+func (mm MeterMust) NewFloat64GaugeObserver(name string, callback Float64ObserverFunc, oos ...InstrumentOption) Float64GaugeObserver {
+	if inst, err := mm.meter.NewFloat64GaugeObserver(name, callback, oos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewInt64CounterObserver calls `Meter.NewInt64CounterObserver` and
+// returns the instrument, panicking if it encounters an error.
+func (mm MeterMust) NewInt64CounterObserver(name string, callback Int64ObserverFunc, oos ...InstrumentOption) Int64CounterObserver {
+	if inst, err := mm.meter.NewInt64CounterObserver(name, callback, oos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewFloat64CounterObserver calls `Meter.NewFloat64CounterObserver` and
+// returns the instrument, panicking if it encounters an error.
+func (mm MeterMust) NewFloat64CounterObserver(name string, callback Float64ObserverFunc, oos ...InstrumentOption) Float64CounterObserver {
+	if inst, err := mm.meter.NewFloat64CounterObserver(name, callback, oos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewInt64UpDownCounterObserver calls `Meter.NewInt64UpDownCounterObserver` and
+// returns the instrument, panicking if it encounters an error.
+func (mm MeterMust) NewInt64UpDownCounterObserver(name string, callback Int64ObserverFunc, oos ...InstrumentOption) Int64UpDownCounterObserver {
+	if inst, err := mm.meter.NewInt64UpDownCounterObserver(name, callback, oos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewFloat64UpDownCounterObserver calls `Meter.NewFloat64UpDownCounterObserver` and
+// returns the instrument, panicking if it encounters an error.
+func (mm MeterMust) NewFloat64UpDownCounterObserver(name string, callback Float64ObserverFunc, oos ...InstrumentOption) Float64UpDownCounterObserver {
+	if inst, err := mm.meter.NewFloat64UpDownCounterObserver(name, callback, oos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewBatchObserver returns a wrapper around BatchObserver that panics
+// when any instrument constructor returns an error.
+func (mm MeterMust) NewBatchObserver(callback BatchObserverFunc) BatchObserverMust {
+	return BatchObserverMust{
+		batch: mm.meter.NewBatchObserver(callback),
+	}
+}
+
+// NewInt64GaugeObserver calls `BatchObserver.NewInt64GaugeObserver` and
+// returns the instrument, panicking if it encounters an error.
+func (bm BatchObserverMust) NewInt64GaugeObserver(name string, oos ...InstrumentOption) Int64GaugeObserver {
+	if inst, err := bm.batch.NewInt64GaugeObserver(name, oos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewFloat64GaugeObserver calls `BatchObserver.NewFloat64GaugeObserver` and
+// returns the instrument, panicking if it encounters an error.
+func (bm BatchObserverMust) NewFloat64GaugeObserver(name string, oos ...InstrumentOption) Float64GaugeObserver {
+	if inst, err := bm.batch.NewFloat64GaugeObserver(name, oos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewInt64CounterObserver calls `BatchObserver.NewInt64CounterObserver` and
+// returns the instrument, panicking if it encounters an error.
+func (bm BatchObserverMust) NewInt64CounterObserver(name string, oos ...InstrumentOption) Int64CounterObserver {
+	if inst, err := bm.batch.NewInt64CounterObserver(name, oos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewFloat64CounterObserver calls `BatchObserver.NewFloat64CounterObserver` and
+// returns the instrument, panicking if it encounters an error.
+func (bm BatchObserverMust) NewFloat64CounterObserver(name string, oos ...InstrumentOption) Float64CounterObserver {
+	if inst, err := bm.batch.NewFloat64CounterObserver(name, oos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewInt64UpDownCounterObserver calls `BatchObserver.NewInt64UpDownCounterObserver` and
+// returns the instrument, panicking if it encounters an error.
+func (bm BatchObserverMust) NewInt64UpDownCounterObserver(name string, oos ...InstrumentOption) Int64UpDownCounterObserver {
+	if inst, err := bm.batch.NewInt64UpDownCounterObserver(name, oos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewFloat64UpDownCounterObserver calls `BatchObserver.NewFloat64UpDownCounterObserver` and
+// returns the instrument, panicking if it encounters an error.
+func (bm BatchObserverMust) NewFloat64UpDownCounterObserver(name string, oos ...InstrumentOption) Float64UpDownCounterObserver {
+	if inst, err := bm.batch.NewFloat64UpDownCounterObserver(name, oos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}

vendor/go.opentelemetry.io/otel/metric/metric_instrument.go

@@ -0,0 +1,464 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package metric // import "go.opentelemetry.io/otel/metric"
+
+import (
+	"context"
+	"errors"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric/number"
+	"go.opentelemetry.io/otel/metric/sdkapi"
+)
+
+// ErrSDKReturnedNilImpl is returned when a new `MeterImpl` returns nil.
+var ErrSDKReturnedNilImpl = errors.New("SDK returned a nil implementation")
+
+// Int64ObserverFunc is a type of callback that integral
+// observers run.
+type Int64ObserverFunc func(context.Context, Int64ObserverResult)
+
+// Float64ObserverFunc is a type of callback that floating point
+// observers run.
+type Float64ObserverFunc func(context.Context, Float64ObserverResult)
+
+// BatchObserverFunc is a callback argument for use with any
+// Observer instrument that will be reported as a batch of
+// observations.
+type BatchObserverFunc func(context.Context, BatchObserverResult)
+
+// Int64ObserverResult is passed to an observer callback to capture
+// observations for one asynchronous integer metric instrument.
+type Int64ObserverResult struct {
+	instrument sdkapi.AsyncImpl
+	function   func([]attribute.KeyValue, ...Observation)
+}
+
+// Float64ObserverResult is passed to an observer callback to capture
+// observations for one asynchronous floating point metric instrument.
+type Float64ObserverResult struct {
+	instrument sdkapi.AsyncImpl
+	function   func([]attribute.KeyValue, ...Observation)
+}
+
+// BatchObserverResult is passed to a batch observer callback to
+// capture observations for multiple asynchronous instruments.
+type BatchObserverResult struct {
+	function func([]attribute.KeyValue, ...Observation)
+}
+
+// Observe captures a single integer value from the associated
+// instrument callback, with the given labels.
+func (ir Int64ObserverResult) Observe(value int64, labels ...attribute.KeyValue) {
+	ir.function(labels, sdkapi.NewObservation(ir.instrument, number.NewInt64Number(value)))
+}
+
+// Observe captures a single floating point value from the associated
+// instrument callback, with the given labels.
+func (fr Float64ObserverResult) Observe(value float64, labels ...attribute.KeyValue) {
+	fr.function(labels, sdkapi.NewObservation(fr.instrument, number.NewFloat64Number(value)))
+}
+
+// Observe captures a multiple observations from the associated batch
+// instrument callback, with the given labels.
+func (br BatchObserverResult) Observe(labels []attribute.KeyValue, obs ...Observation) {
+	br.function(labels, obs...)
+}
+
+var _ sdkapi.AsyncSingleRunner = (*Int64ObserverFunc)(nil)
+var _ sdkapi.AsyncSingleRunner = (*Float64ObserverFunc)(nil)
+var _ sdkapi.AsyncBatchRunner = (*BatchObserverFunc)(nil)
+
+// newInt64AsyncRunner returns a single-observer callback for integer Observer instruments.
+func newInt64AsyncRunner(c Int64ObserverFunc) sdkapi.AsyncSingleRunner {
+	return &c
+}
+
+// newFloat64AsyncRunner returns a single-observer callback for floating point Observer instruments.
+func newFloat64AsyncRunner(c Float64ObserverFunc) sdkapi.AsyncSingleRunner {
+	return &c
+}
+
+// newBatchAsyncRunner returns a batch-observer callback use with multiple Observer instruments.
+func newBatchAsyncRunner(c BatchObserverFunc) sdkapi.AsyncBatchRunner {
+	return &c
+}
+
+// AnyRunner implements AsyncRunner.
+func (*Int64ObserverFunc) AnyRunner() {}
+
+// AnyRunner implements AsyncRunner.
+func (*Float64ObserverFunc) AnyRunner() {}
+
+// AnyRunner implements AsyncRunner.
+func (*BatchObserverFunc) AnyRunner() {}
+
+// Run implements AsyncSingleRunner.
+func (i *Int64ObserverFunc) Run(ctx context.Context, impl sdkapi.AsyncImpl, function func([]attribute.KeyValue, ...Observation)) {
+	(*i)(ctx, Int64ObserverResult{
+		instrument: impl,
+		function:   function,
+	})
+}
+
+// Run implements AsyncSingleRunner.
+func (f *Float64ObserverFunc) Run(ctx context.Context, impl sdkapi.AsyncImpl, function func([]attribute.KeyValue, ...Observation)) {
+	(*f)(ctx, Float64ObserverResult{
+		instrument: impl,
+		function:   function,
+	})
+}
+
+// Run implements AsyncBatchRunner.
+func (b *BatchObserverFunc) Run(ctx context.Context, function func([]attribute.KeyValue, ...Observation)) {
+	(*b)(ctx, BatchObserverResult{
+		function: function,
+	})
+}
+
+// wrapInt64GaugeObserverInstrument converts an AsyncImpl into Int64GaugeObserver.
+func wrapInt64GaugeObserverInstrument(asyncInst sdkapi.AsyncImpl, err error) (Int64GaugeObserver, error) {
+	common, err := checkNewAsync(asyncInst, err)
+	return Int64GaugeObserver{asyncInstrument: common}, err
+}
+
+// wrapFloat64GaugeObserverInstrument converts an AsyncImpl into Float64GaugeObserver.
+func wrapFloat64GaugeObserverInstrument(asyncInst sdkapi.AsyncImpl, err error) (Float64GaugeObserver, error) {
+	common, err := checkNewAsync(asyncInst, err)
+	return Float64GaugeObserver{asyncInstrument: common}, err
+}
+
+// wrapInt64CounterObserverInstrument converts an AsyncImpl into Int64CounterObserver.
+func wrapInt64CounterObserverInstrument(asyncInst sdkapi.AsyncImpl, err error) (Int64CounterObserver, error) {
+	common, err := checkNewAsync(asyncInst, err)
+	return Int64CounterObserver{asyncInstrument: common}, err
+}
+
+// wrapFloat64CounterObserverInstrument converts an AsyncImpl into Float64CounterObserver.
+func wrapFloat64CounterObserverInstrument(asyncInst sdkapi.AsyncImpl, err error) (Float64CounterObserver, error) {
+	common, err := checkNewAsync(asyncInst, err)
+	return Float64CounterObserver{asyncInstrument: common}, err
+}
+
+// wrapInt64UpDownCounterObserverInstrument converts an AsyncImpl into Int64UpDownCounterObserver.
+func wrapInt64UpDownCounterObserverInstrument(asyncInst sdkapi.AsyncImpl, err error) (Int64UpDownCounterObserver, error) {
+	common, err := checkNewAsync(asyncInst, err)
+	return Int64UpDownCounterObserver{asyncInstrument: common}, err
+}
+
+// wrapFloat64UpDownCounterObserverInstrument converts an AsyncImpl into Float64UpDownCounterObserver.
+func wrapFloat64UpDownCounterObserverInstrument(asyncInst sdkapi.AsyncImpl, err error) (Float64UpDownCounterObserver, error) {
+	common, err := checkNewAsync(asyncInst, err)
+	return Float64UpDownCounterObserver{asyncInstrument: common}, err
+}
+
+// BatchObserver represents an Observer callback that can report
+// observations for multiple instruments.
+type BatchObserver struct {
+	meter  Meter
+	runner sdkapi.AsyncBatchRunner
+}
+
+// Int64GaugeObserver is a metric that captures a set of int64 values at a
+// point in time.
+type Int64GaugeObserver struct {
+	asyncInstrument
+}
+
+// Float64GaugeObserver is a metric that captures a set of float64 values
+// at a point in time.
+type Float64GaugeObserver struct {
+	asyncInstrument
+}
+
+// Int64CounterObserver is a metric that captures a precomputed sum of
+// int64 values at a point in time.
+type Int64CounterObserver struct {
+	asyncInstrument
+}
+
+// Float64CounterObserver is a metric that captures a precomputed sum of
+// float64 values at a point in time.
+type Float64CounterObserver struct {
+	asyncInstrument
+}
+
+// Int64UpDownCounterObserver is a metric that captures a precomputed sum of
+// int64 values at a point in time.
+type Int64UpDownCounterObserver struct {
+	asyncInstrument
+}
+
+// Float64UpDownCounterObserver is a metric that captures a precomputed sum of
+// float64 values at a point in time.
+type Float64UpDownCounterObserver struct {
+	asyncInstrument
+}
+
+// Observation returns an Observation, a BatchObserverFunc
+// argument, for an asynchronous integer instrument.
+// This returns an implementation-level object for use by the SDK,
+// users should not refer to this.
+func (i Int64GaugeObserver) Observation(v int64) Observation {
+	return sdkapi.NewObservation(i.instrument, number.NewInt64Number(v))
+}
+
+// Observation returns an Observation, a BatchObserverFunc
+// argument, for an asynchronous integer instrument.
+// This returns an implementation-level object for use by the SDK,
+// users should not refer to this.
+func (f Float64GaugeObserver) Observation(v float64) Observation {
+	return sdkapi.NewObservation(f.instrument, number.NewFloat64Number(v))
+}
+
+// Observation returns an Observation, a BatchObserverFunc
+// argument, for an asynchronous integer instrument.
+// This returns an implementation-level object for use by the SDK,
+// users should not refer to this.
+func (i Int64CounterObserver) Observation(v int64) Observation {
+	return sdkapi.NewObservation(i.instrument, number.NewInt64Number(v))
+}
+
+// Observation returns an Observation, a BatchObserverFunc
+// argument, for an asynchronous integer instrument.
+// This returns an implementation-level object for use by the SDK,
+// users should not refer to this.
+func (f Float64CounterObserver) Observation(v float64) Observation {
+	return sdkapi.NewObservation(f.instrument, number.NewFloat64Number(v))
+}
+
+// Observation returns an Observation, a BatchObserverFunc
+// argument, for an asynchronous integer instrument.
+// This returns an implementation-level object for use by the SDK,
+// users should not refer to this.
+func (i Int64UpDownCounterObserver) Observation(v int64) Observation {
+	return sdkapi.NewObservation(i.instrument, number.NewInt64Number(v))
+}
+
+// Observation returns an Observation, a BatchObserverFunc
+// argument, for an asynchronous integer instrument.
+// This returns an implementation-level object for use by the SDK,
+// users should not refer to this.
+func (f Float64UpDownCounterObserver) Observation(v float64) Observation {
+	return sdkapi.NewObservation(f.instrument, number.NewFloat64Number(v))
+}
+
+// syncInstrument contains a SyncImpl.
+type syncInstrument struct {
+	instrument sdkapi.SyncImpl
+}
+
+// asyncInstrument contains a AsyncImpl.
+type asyncInstrument struct {
+	instrument sdkapi.AsyncImpl
+}
+
+// AsyncImpl implements AsyncImpl.
+func (a asyncInstrument) AsyncImpl() sdkapi.AsyncImpl {
+	return a.instrument
+}
+
+// SyncImpl returns the implementation object for synchronous instruments.
+func (s syncInstrument) SyncImpl() sdkapi.SyncImpl {
+	return s.instrument
+}
+
+func (s syncInstrument) float64Measurement(value float64) Measurement {
+	return sdkapi.NewMeasurement(s.instrument, number.NewFloat64Number(value))
+}
+
+func (s syncInstrument) int64Measurement(value int64) Measurement {
+	return sdkapi.NewMeasurement(s.instrument, number.NewInt64Number(value))
+}
+
+func (s syncInstrument) directRecord(ctx context.Context, number number.Number, labels []attribute.KeyValue) {
+	s.instrument.RecordOne(ctx, number, labels)
+}
+
+// checkNewAsync receives an AsyncImpl and potential
+// error, and returns the same types, checking for and ensuring that
+// the returned interface is not nil.
+func checkNewAsync(instrument sdkapi.AsyncImpl, err error) (asyncInstrument, error) {
+	if instrument == nil {
+		if err == nil {
+			err = ErrSDKReturnedNilImpl
+		}
+		instrument = sdkapi.NewNoopAsyncInstrument()
+	}
+	return asyncInstrument{
+		instrument: instrument,
+	}, err
+}
+
+// checkNewSync receives an SyncImpl and potential
+// error, and returns the same types, checking for and ensuring that
+// the returned interface is not nil.
+func checkNewSync(instrument sdkapi.SyncImpl, err error) (syncInstrument, error) {
+	if instrument == nil {
+		if err == nil {
+			err = ErrSDKReturnedNilImpl
+		}
+		// Note: an alternate behavior would be to synthesize a new name
+		// or group all duplicately-named instruments of a certain type
+		// together and use a tag for the original name, e.g.,
+		//   name = 'invalid.counter.int64'
+		//   label = 'original-name=duplicate-counter-name'
+		instrument = sdkapi.NewNoopSyncInstrument()
+	}
+	return syncInstrument{
+		instrument: instrument,
+	}, err
+}
+
+// wrapInt64CounterInstrument converts a SyncImpl into Int64Counter.
+func wrapInt64CounterInstrument(syncInst sdkapi.SyncImpl, err error) (Int64Counter, error) {
+	common, err := checkNewSync(syncInst, err)
+	return Int64Counter{syncInstrument: common}, err
+}
+
+// wrapFloat64CounterInstrument converts a SyncImpl into Float64Counter.
+func wrapFloat64CounterInstrument(syncInst sdkapi.SyncImpl, err error) (Float64Counter, error) {
+	common, err := checkNewSync(syncInst, err)
+	return Float64Counter{syncInstrument: common}, err
+}
+
+// wrapInt64UpDownCounterInstrument converts a SyncImpl into Int64UpDownCounter.
+func wrapInt64UpDownCounterInstrument(syncInst sdkapi.SyncImpl, err error) (Int64UpDownCounter, error) {
+	common, err := checkNewSync(syncInst, err)
+	return Int64UpDownCounter{syncInstrument: common}, err
+}
+
+// wrapFloat64UpDownCounterInstrument converts a SyncImpl into Float64UpDownCounter.
+func wrapFloat64UpDownCounterInstrument(syncInst sdkapi.SyncImpl, err error) (Float64UpDownCounter, error) {
+	common, err := checkNewSync(syncInst, err)
+	return Float64UpDownCounter{syncInstrument: common}, err
+}
+
+// wrapInt64HistogramInstrument converts a SyncImpl into Int64Histogram.
+func wrapInt64HistogramInstrument(syncInst sdkapi.SyncImpl, err error) (Int64Histogram, error) {
+	common, err := checkNewSync(syncInst, err)
+	return Int64Histogram{syncInstrument: common}, err
+}
+
+// wrapFloat64HistogramInstrument converts a SyncImpl into Float64Histogram.
+func wrapFloat64HistogramInstrument(syncInst sdkapi.SyncImpl, err error) (Float64Histogram, error) {
+	common, err := checkNewSync(syncInst, err)
+	return Float64Histogram{syncInstrument: common}, err
+}
+
+// Float64Counter is a metric that accumulates float64 values.
+type Float64Counter struct {
+	syncInstrument
+}
+
+// Int64Counter is a metric that accumulates int64 values.
+type Int64Counter struct {
+	syncInstrument
+}
+
+// Measurement creates a Measurement object to use with batch
+// recording.
+func (c Float64Counter) Measurement(value float64) Measurement {
+	return c.float64Measurement(value)
+}
+
+// Measurement creates a Measurement object to use with batch
+// recording.
+func (c Int64Counter) Measurement(value int64) Measurement {
+	return c.int64Measurement(value)
+}
+
+// Add adds the value to the counter's sum. The labels should contain
+// the keys and values to be associated with this value.
+func (c Float64Counter) Add(ctx context.Context, value float64, labels ...attribute.KeyValue) {
+	c.directRecord(ctx, number.NewFloat64Number(value), labels)
+}
+
+// Add adds the value to the counter's sum. The labels should contain
+// the keys and values to be associated with this value.
+func (c Int64Counter) Add(ctx context.Context, value int64, labels ...attribute.KeyValue) {
+	c.directRecord(ctx, number.NewInt64Number(value), labels)
+}
+
+// Float64UpDownCounter is a metric instrument that sums floating
+// point values.
+type Float64UpDownCounter struct {
+	syncInstrument
+}
+
+// Int64UpDownCounter is a metric instrument that sums integer values.
+type Int64UpDownCounter struct {
+	syncInstrument
+}
+
+// Measurement creates a Measurement object to use with batch
+// recording.
+func (c Float64UpDownCounter) Measurement(value float64) Measurement {
+	return c.float64Measurement(value)
+}
+
+// Measurement creates a Measurement object to use with batch
+// recording.
+func (c Int64UpDownCounter) Measurement(value int64) Measurement {
+	return c.int64Measurement(value)
+}
+
+// Add adds the value to the counter's sum. The labels should contain
+// the keys and values to be associated with this value.
+func (c Float64UpDownCounter) Add(ctx context.Context, value float64, labels ...attribute.KeyValue) {
+	c.directRecord(ctx, number.NewFloat64Number(value), labels)
+}
+
+// Add adds the value to the counter's sum. The labels should contain
+// the keys and values to be associated with this value.
+func (c Int64UpDownCounter) Add(ctx context.Context, value int64, labels ...attribute.KeyValue) {
+	c.directRecord(ctx, number.NewInt64Number(value), labels)
+}
+
+// Float64Histogram is a metric that records float64 values.
+type Float64Histogram struct {
+	syncInstrument
+}
+
+// Int64Histogram is a metric that records int64 values.
+type Int64Histogram struct {
+	syncInstrument
+}
+
+// Measurement creates a Measurement object to use with batch
+// recording.
+func (c Float64Histogram) Measurement(value float64) Measurement {
+	return c.float64Measurement(value)
+}
+
+// Measurement creates a Measurement object to use with batch
+// recording.
+func (c Int64Histogram) Measurement(value int64) Measurement {
+	return c.int64Measurement(value)
+}
+
+// Record adds a new value to the list of Histogram's records. The
+// labels should contain the keys and values to be associated with
+// this value.
+func (c Float64Histogram) Record(ctx context.Context, value float64, labels ...attribute.KeyValue) {
+	c.directRecord(ctx, number.NewFloat64Number(value), labels)
+}
+
+// Record adds a new value to the Histogram's distribution. The
+// labels should contain the keys and values to be associated with
+// this value.
+func (c Int64Histogram) Record(ctx context.Context, value int64, labels ...attribute.KeyValue) {
+	c.directRecord(ctx, number.NewInt64Number(value), labels)
+}

vendor/go.opentelemetry.io/otel/metric/noop.go

@@ -0,0 +1,30 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package metric // import "go.opentelemetry.io/otel/metric"
+
+type noopMeterProvider struct{}
+
+// NewNoopMeterProvider returns an implementation of MeterProvider that
+// performs no operations. The Meter and Instrument created from the returned
+// MeterProvider also perform no operations.
+func NewNoopMeterProvider() MeterProvider {
+	return noopMeterProvider{}
+}
+
+var _ MeterProvider = noopMeterProvider{}
+
+func (noopMeterProvider) Meter(instrumentationName string, opts ...MeterOption) Meter {
+	return Meter{}
+}

vendor/go.opentelemetry.io/otel/metric/number/doc.go

@@ -0,0 +1,23 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/*
+Package number provides a number abstraction for instruments that
+either support int64 or float64 input values.
+
+This package is currently in a pre-GA phase. Backwards incompatible changes
+may be introduced in subsequent minor version releases as we work to track the
+evolving OpenTelemetry specification and user feedback.
+*/
+package number // import "go.opentelemetry.io/otel/metric/number"

vendor/go.opentelemetry.io/otel/metric/number/kind_string.go

@@ -0,0 +1,24 @@
+// Code generated by "stringer -type=Kind"; DO NOT EDIT.
+
+package number
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[Int64Kind-0]
+	_ = x[Float64Kind-1]
+}
+
+const _Kind_name = "Int64KindFloat64Kind"
+
+var _Kind_index = [...]uint8{0, 9, 20}
+
+func (i Kind) String() string {
+	if i < 0 || i >= Kind(len(_Kind_index)-1) {
+		return "Kind(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+	return _Kind_name[_Kind_index[i]:_Kind_index[i+1]]
+}

vendor/go.opentelemetry.io/otel/metric/number/number.go

@@ -0,0 +1,538 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package number // import "go.opentelemetry.io/otel/metric/number"
+
+//go:generate stringer -type=Kind
+
+import (
+	"fmt"
+	"math"
+	"sync/atomic"
+
+	"go.opentelemetry.io/otel/internal"
+)
+
+// Kind describes the data type of the Number.
+type Kind int8
+
+const (
+	// Int64Kind means that the Number stores int64.
+	Int64Kind Kind = iota
+	// Float64Kind means that the Number stores float64.
+	Float64Kind
+)
+
+// Zero returns a zero value for a given Kind
+func (k Kind) Zero() Number {
+	switch k {
+	case Int64Kind:
+		return NewInt64Number(0)
+	case Float64Kind:
+		return NewFloat64Number(0.)
+	default:
+		return Number(0)
+	}
+}
+
+// Minimum returns the minimum representable value
+// for a given Kind
+func (k Kind) Minimum() Number {
+	switch k {
+	case Int64Kind:
+		return NewInt64Number(math.MinInt64)
+	case Float64Kind:
+		return NewFloat64Number(-1. * math.MaxFloat64)
+	default:
+		return Number(0)
+	}
+}
+
+// Maximum returns the maximum representable value
+// for a given Kind
+func (k Kind) Maximum() Number {
+	switch k {
+	case Int64Kind:
+		return NewInt64Number(math.MaxInt64)
+	case Float64Kind:
+		return NewFloat64Number(math.MaxFloat64)
+	default:
+		return Number(0)
+	}
+}
+
+// Number represents either an integral or a floating point value. It
+// needs to be accompanied with a source of Kind that describes
+// the actual type of the value stored within Number.
+type Number uint64
+
+// - constructors
+
+// NewNumberFromRaw creates a new Number from a raw value.
+func NewNumberFromRaw(r uint64) Number {
+	return Number(r)
+}
+
+// NewInt64Number creates an integral Number.
+func NewInt64Number(i int64) Number {
+	return NewNumberFromRaw(internal.Int64ToRaw(i))
+}
+
+// NewFloat64Number creates a floating point Number.
+func NewFloat64Number(f float64) Number {
+	return NewNumberFromRaw(internal.Float64ToRaw(f))
+}
+
+// NewNumberSignChange returns a number with the same magnitude and
+// the opposite sign.  `kind` must describe the kind of number in `nn`.
+func NewNumberSignChange(kind Kind, nn Number) Number {
+	switch kind {
+	case Int64Kind:
+		return NewInt64Number(-nn.AsInt64())
+	case Float64Kind:
+		return NewFloat64Number(-nn.AsFloat64())
+	}
+	return nn
+}
+
+// - as x
+
+// AsNumber gets the Number.
+func (n *Number) AsNumber() Number {
+	return *n
+}
+
+// AsRaw gets the uninterpreted raw value. Might be useful for some
+// atomic operations.
+func (n *Number) AsRaw() uint64 {
+	return uint64(*n)
+}
+
+// AsInt64 assumes that the value contains an int64 and returns it as
+// such.
+func (n *Number) AsInt64() int64 {
+	return internal.RawToInt64(n.AsRaw())
+}
+
+// AsFloat64 assumes that the measurement value contains a float64 and
+// returns it as such.
+func (n *Number) AsFloat64() float64 {
+	return internal.RawToFloat64(n.AsRaw())
+}
+
+// - as x atomic
+
+// AsNumberAtomic gets the Number atomically.
+func (n *Number) AsNumberAtomic() Number {
+	return NewNumberFromRaw(n.AsRawAtomic())
+}
+
+// AsRawAtomic gets the uninterpreted raw value atomically. Might be
+// useful for some atomic operations.
+func (n *Number) AsRawAtomic() uint64 {
+	return atomic.LoadUint64(n.AsRawPtr())
+}
+
+// AsInt64Atomic assumes that the number contains an int64 and returns
+// it as such atomically.
+func (n *Number) AsInt64Atomic() int64 {
+	return atomic.LoadInt64(n.AsInt64Ptr())
+}
+
+// AsFloat64Atomic assumes that the measurement value contains a
+// float64 and returns it as such atomically.
+func (n *Number) AsFloat64Atomic() float64 {
+	return internal.RawToFloat64(n.AsRawAtomic())
+}
+
+// - as x ptr
+
+// AsRawPtr gets the pointer to the raw, uninterpreted raw
+// value. Might be useful for some atomic operations.
+func (n *Number) AsRawPtr() *uint64 {
+	return (*uint64)(n)
+}
+
+// AsInt64Ptr assumes that the number contains an int64 and returns a
+// pointer to it.
+func (n *Number) AsInt64Ptr() *int64 {
+	return internal.RawPtrToInt64Ptr(n.AsRawPtr())
+}
+
+// AsFloat64Ptr assumes that the number contains a float64 and returns a
+// pointer to it.
+func (n *Number) AsFloat64Ptr() *float64 {
+	return internal.RawPtrToFloat64Ptr(n.AsRawPtr())
+}
+
+// - coerce
+
+// CoerceToInt64 casts the number to int64. May result in
+// data/precision loss.
+func (n *Number) CoerceToInt64(kind Kind) int64 {
+	switch kind {
+	case Int64Kind:
+		return n.AsInt64()
+	case Float64Kind:
+		return int64(n.AsFloat64())
+	default:
+		// you get what you deserve
+		return 0
+	}
+}
+
+// CoerceToFloat64 casts the number to float64. May result in
+// data/precision loss.
+func (n *Number) CoerceToFloat64(kind Kind) float64 {
+	switch kind {
+	case Int64Kind:
+		return float64(n.AsInt64())
+	case Float64Kind:
+		return n.AsFloat64()
+	default:
+		// you get what you deserve
+		return 0
+	}
+}
+
+// - set
+
+// SetNumber sets the number to the passed number. Both should be of
+// the same kind.
+func (n *Number) SetNumber(nn Number) {
+	*n.AsRawPtr() = nn.AsRaw()
+}
+
+// SetRaw sets the number to the passed raw value. Both number and the
+// raw number should represent the same kind.
+func (n *Number) SetRaw(r uint64) {
+	*n.AsRawPtr() = r
+}
+
+// SetInt64 assumes that the number contains an int64 and sets it to
+// the passed value.
+func (n *Number) SetInt64(i int64) {
+	*n.AsInt64Ptr() = i
+}
+
+// SetFloat64 assumes that the number contains a float64 and sets it
+// to the passed value.
+func (n *Number) SetFloat64(f float64) {
+	*n.AsFloat64Ptr() = f
+}
+
+// - set atomic
+
+// SetNumberAtomic sets the number to the passed number
+// atomically. Both should be of the same kind.
+func (n *Number) SetNumberAtomic(nn Number) {
+	atomic.StoreUint64(n.AsRawPtr(), nn.AsRaw())
+}
+
+// SetRawAtomic sets the number to the passed raw value
+// atomically. Both number and the raw number should represent the
+// same kind.
+func (n *Number) SetRawAtomic(r uint64) {
+	atomic.StoreUint64(n.AsRawPtr(), r)
+}
+
+// SetInt64Atomic assumes that the number contains an int64 and sets
+// it to the passed value atomically.
+func (n *Number) SetInt64Atomic(i int64) {
+	atomic.StoreInt64(n.AsInt64Ptr(), i)
+}
+
+// SetFloat64Atomic assumes that the number contains a float64 and
+// sets it to the passed value atomically.
+func (n *Number) SetFloat64Atomic(f float64) {
+	atomic.StoreUint64(n.AsRawPtr(), internal.Float64ToRaw(f))
+}
+
+// - swap
+
+// SwapNumber sets the number to the passed number and returns the old
+// number. Both this number and the passed number should be of the
+// same kind.
+func (n *Number) SwapNumber(nn Number) Number {
+	old := *n
+	n.SetNumber(nn)
+	return old
+}
+
+// SwapRaw sets the number to the passed raw value and returns the old
+// raw value. Both number and the raw number should represent the same
+// kind.
+func (n *Number) SwapRaw(r uint64) uint64 {
+	old := n.AsRaw()
+	n.SetRaw(r)
+	return old
+}
+
+// SwapInt64 assumes that the number contains an int64, sets it to the
+// passed value and returns the old int64 value.
+func (n *Number) SwapInt64(i int64) int64 {
+	old := n.AsInt64()
+	n.SetInt64(i)
+	return old
+}
+
+// SwapFloat64 assumes that the number contains an float64, sets it to
+// the passed value and returns the old float64 value.
+func (n *Number) SwapFloat64(f float64) float64 {
+	old := n.AsFloat64()
+	n.SetFloat64(f)
+	return old
+}
+
+// - swap atomic
+
+// SwapNumberAtomic sets the number to the passed number and returns
+// the old number atomically. Both this number and the passed number
+// should be of the same kind.
+func (n *Number) SwapNumberAtomic(nn Number) Number {
+	return NewNumberFromRaw(atomic.SwapUint64(n.AsRawPtr(), nn.AsRaw()))
+}
+
+// SwapRawAtomic sets the number to the passed raw value and returns
+// the old raw value atomically. Both number and the raw number should
+// represent the same kind.
+func (n *Number) SwapRawAtomic(r uint64) uint64 {
+	return atomic.SwapUint64(n.AsRawPtr(), r)
+}
+
+// SwapInt64Atomic assumes that the number contains an int64, sets it
+// to the passed value and returns the old int64 value atomically.
+func (n *Number) SwapInt64Atomic(i int64) int64 {
+	return atomic.SwapInt64(n.AsInt64Ptr(), i)
+}
+
+// SwapFloat64Atomic assumes that the number contains an float64, sets
+// it to the passed value and returns the old float64 value
+// atomically.
+func (n *Number) SwapFloat64Atomic(f float64) float64 {
+	return internal.RawToFloat64(atomic.SwapUint64(n.AsRawPtr(), internal.Float64ToRaw(f)))
+}
+
+// - add
+
+// AddNumber assumes that this and the passed number are of the passed
+// kind and adds the passed number to this number.
+func (n *Number) AddNumber(kind Kind, nn Number) {
+	switch kind {
+	case Int64Kind:
+		n.AddInt64(nn.AsInt64())
+	case Float64Kind:
+		n.AddFloat64(nn.AsFloat64())
+	}
+}
+
+// AddRaw assumes that this number and the passed raw value are of the
+// passed kind and adds the passed raw value to this number.
+func (n *Number) AddRaw(kind Kind, r uint64) {
+	n.AddNumber(kind, NewNumberFromRaw(r))
+}
+
+// AddInt64 assumes that the number contains an int64 and adds the
+// passed int64 to it.
+func (n *Number) AddInt64(i int64) {
+	*n.AsInt64Ptr() += i
+}
+
+// AddFloat64 assumes that the number contains a float64 and adds the
+// passed float64 to it.
+func (n *Number) AddFloat64(f float64) {
+	*n.AsFloat64Ptr() += f
+}
+
+// - add atomic
+
+// AddNumberAtomic assumes that this and the passed number are of the
+// passed kind and adds the passed number to this number atomically.
+func (n *Number) AddNumberAtomic(kind Kind, nn Number) {
+	switch kind {
+	case Int64Kind:
+		n.AddInt64Atomic(nn.AsInt64())
+	case Float64Kind:
+		n.AddFloat64Atomic(nn.AsFloat64())
+	}
+}
+
+// AddRawAtomic assumes that this number and the passed raw value are
+// of the passed kind and adds the passed raw value to this number
+// atomically.
+func (n *Number) AddRawAtomic(kind Kind, r uint64) {
+	n.AddNumberAtomic(kind, NewNumberFromRaw(r))
+}
+
+// AddInt64Atomic assumes that the number contains an int64 and adds
+// the passed int64 to it atomically.
+func (n *Number) AddInt64Atomic(i int64) {
+	atomic.AddInt64(n.AsInt64Ptr(), i)
+}
+
+// AddFloat64Atomic assumes that the number contains a float64 and
+// adds the passed float64 to it atomically.
+func (n *Number) AddFloat64Atomic(f float64) {
+	for {
+		o := n.AsFloat64Atomic()
+		if n.CompareAndSwapFloat64(o, o+f) {
+			break
+		}
+	}
+}
+
+// - compare and swap (atomic only)
+
+// CompareAndSwapNumber does the atomic CAS operation on this
+// number. This number and passed old and new numbers should be of the
+// same kind.
+func (n *Number) CompareAndSwapNumber(on, nn Number) bool {
+	return atomic.CompareAndSwapUint64(n.AsRawPtr(), on.AsRaw(), nn.AsRaw())
+}
+
+// CompareAndSwapRaw does the atomic CAS operation on this
+// number. This number and passed old and new raw values should be of
+// the same kind.
+func (n *Number) CompareAndSwapRaw(or, nr uint64) bool {
+	return atomic.CompareAndSwapUint64(n.AsRawPtr(), or, nr)
+}
+
+// CompareAndSwapInt64 assumes that this number contains an int64 and
+// does the atomic CAS operation on it.
+func (n *Number) CompareAndSwapInt64(oi, ni int64) bool {
+	return atomic.CompareAndSwapInt64(n.AsInt64Ptr(), oi, ni)
+}
+
+// CompareAndSwapFloat64 assumes that this number contains a float64 and
+// does the atomic CAS operation on it.
+func (n *Number) CompareAndSwapFloat64(of, nf float64) bool {
+	return atomic.CompareAndSwapUint64(n.AsRawPtr(), internal.Float64ToRaw(of), internal.Float64ToRaw(nf))
+}
+
+// - compare
+
+// CompareNumber compares two Numbers given their kind.  Both numbers
+// should have the same kind.  This returns:
+//    0 if the numbers are equal
+//    -1 if the subject `n` is less than the argument `nn`
+//    +1 if the subject `n` is greater than the argument `nn`
+func (n *Number) CompareNumber(kind Kind, nn Number) int {
+	switch kind {
+	case Int64Kind:
+		return n.CompareInt64(nn.AsInt64())
+	case Float64Kind:
+		return n.CompareFloat64(nn.AsFloat64())
+	default:
+		// you get what you deserve
+		return 0
+	}
+}
+
+// CompareRaw compares two numbers, where one is input as a raw
+// uint64, interpreting both values as a `kind` of number.
+func (n *Number) CompareRaw(kind Kind, r uint64) int {
+	return n.CompareNumber(kind, NewNumberFromRaw(r))
+}
+
+// CompareInt64 assumes that the Number contains an int64 and performs
+// a comparison between the value and the other value. It returns the
+// typical result of the compare function: -1 if the value is less
+// than the other, 0 if both are equal, 1 if the value is greater than
+// the other.
+func (n *Number) CompareInt64(i int64) int {
+	this := n.AsInt64()
+	if this < i {
+		return -1
+	} else if this > i {
+		return 1
+	}
+	return 0
+}
+
+// CompareFloat64 assumes that the Number contains a float64 and
+// performs a comparison between the value and the other value. It
+// returns the typical result of the compare function: -1 if the value
+// is less than the other, 0 if both are equal, 1 if the value is
+// greater than the other.
+//
+// Do not compare NaN values.
+func (n *Number) CompareFloat64(f float64) int {
+	this := n.AsFloat64()
+	if this < f {
+		return -1
+	} else if this > f {
+		return 1
+	}
+	return 0
+}
+
+// - relations to zero
+
+// IsPositive returns true if the actual value is greater than zero.
+func (n *Number) IsPositive(kind Kind) bool {
+	return n.compareWithZero(kind) > 0
+}
+
+// IsNegative returns true if the actual value is less than zero.
+func (n *Number) IsNegative(kind Kind) bool {
+	return n.compareWithZero(kind) < 0
+}
+
+// IsZero returns true if the actual value is equal to zero.
+func (n *Number) IsZero(kind Kind) bool {
+	return n.compareWithZero(kind) == 0
+}
+
+// - misc
+
+// Emit returns a string representation of the raw value of the
+// Number. A %d is used for integral values, %f for floating point
+// values.
+func (n *Number) Emit(kind Kind) string {
+	switch kind {
+	case Int64Kind:
+		return fmt.Sprintf("%d", n.AsInt64())
+	case Float64Kind:
+		return fmt.Sprintf("%f", n.AsFloat64())
+	default:
+		return ""
+	}
+}
+
+// AsInterface returns the number as an interface{}, typically used
+// for Kind-correct JSON conversion.
+func (n *Number) AsInterface(kind Kind) interface{} {
+	switch kind {
+	case Int64Kind:
+		return n.AsInt64()
+	case Float64Kind:
+		return n.AsFloat64()
+	default:
+		return math.NaN()
+	}
+}
+
+// - private stuff
+
+func (n *Number) compareWithZero(kind Kind) int {
+	switch kind {
+	case Int64Kind:
+		return n.CompareInt64(0)
+	case Float64Kind:
+		return n.CompareFloat64(0.)
+	default:
+		// you get what you deserve
+		return 0
+	}
+}

vendor/go.opentelemetry.io/otel/metric/sdkapi/descriptor.go

@@ -0,0 +1,70 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package sdkapi // import "go.opentelemetry.io/otel/metric/sdkapi"
+
+import (
+	"go.opentelemetry.io/otel/metric/number"
+	"go.opentelemetry.io/otel/metric/unit"
+)
+
+// Descriptor contains all the settings that describe an instrument,
+// including its name, metric kind, number kind, and the configurable
+// options.
+type Descriptor struct {
+	name           string
+	instrumentKind InstrumentKind
+	numberKind     number.Kind
+	description    string
+	unit           unit.Unit
+}
+
+// NewDescriptor returns a Descriptor with the given contents.
+func NewDescriptor(name string, ikind InstrumentKind, nkind number.Kind, description string, unit unit.Unit) Descriptor {
+	return Descriptor{
+		name:           name,
+		instrumentKind: ikind,
+		numberKind:     nkind,
+		description:    description,
+		unit:           unit,
+	}
+}
+
+// Name returns the metric instrument's name.
+func (d Descriptor) Name() string {
+	return d.name
+}
+
+// InstrumentKind returns the specific kind of instrument.
+func (d Descriptor) InstrumentKind() InstrumentKind {
+	return d.instrumentKind
+}
+
+// Description provides a human-readable description of the metric
+// instrument.
+func (d Descriptor) Description() string {
+	return d.description
+}
+
+// Unit describes the units of the metric instrument.  Unitless
+// metrics return the empty string.
+func (d Descriptor) Unit() unit.Unit {
+	return d.unit
+}
+
+// NumberKind returns whether this instrument is declared over int64,
+// float64, or uint64 values.
+func (d Descriptor) NumberKind() number.Kind {
+	return d.numberKind
+}

vendor/go.opentelemetry.io/otel/metric/sdkapi/instrumentkind.go

@@ -0,0 +1,80 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:generate stringer -type=InstrumentKind
+
+package sdkapi // import "go.opentelemetry.io/otel/metric/sdkapi"
+
+// InstrumentKind describes the kind of instrument.
+type InstrumentKind int8
+
+const (
+	// HistogramInstrumentKind indicates a Histogram instrument.
+	HistogramInstrumentKind InstrumentKind = iota
+	// GaugeObserverInstrumentKind indicates an GaugeObserver instrument.
+	GaugeObserverInstrumentKind
+
+	// CounterInstrumentKind indicates a Counter instrument.
+	CounterInstrumentKind
+	// UpDownCounterInstrumentKind indicates a UpDownCounter instrument.
+	UpDownCounterInstrumentKind
+
+	// CounterObserverInstrumentKind indicates a CounterObserver instrument.
+	CounterObserverInstrumentKind
+	// UpDownCounterObserverInstrumentKind indicates a UpDownCounterObserver
+	// instrument.
+	UpDownCounterObserverInstrumentKind
+)
+
+// Synchronous returns whether this is a synchronous kind of instrument.
+func (k InstrumentKind) Synchronous() bool {
+	switch k {
+	case CounterInstrumentKind, UpDownCounterInstrumentKind, HistogramInstrumentKind:
+		return true
+	}
+	return false
+}
+
+// Asynchronous returns whether this is an asynchronous kind of instrument.
+func (k InstrumentKind) Asynchronous() bool {
+	return !k.Synchronous()
+}
+
+// Adding returns whether this kind of instrument adds its inputs (as opposed to Grouping).
+func (k InstrumentKind) Adding() bool {
+	switch k {
+	case CounterInstrumentKind, UpDownCounterInstrumentKind, CounterObserverInstrumentKind, UpDownCounterObserverInstrumentKind:
+		return true
+	}
+	return false
+}
+
+// Grouping returns whether this kind of instrument groups its inputs (as opposed to Adding).
+func (k InstrumentKind) Grouping() bool {
+	return !k.Adding()
+}
+
+// Monotonic returns whether this kind of instrument exposes a non-decreasing sum.
+func (k InstrumentKind) Monotonic() bool {
+	switch k {
+	case CounterInstrumentKind, CounterObserverInstrumentKind:
+		return true
+	}
+	return false
+}
+
+// PrecomputedSum returns whether this kind of instrument receives precomputed sums.
+func (k InstrumentKind) PrecomputedSum() bool {
+	return k.Adding() && k.Asynchronous()
+}

vendor/go.opentelemetry.io/otel/metric/sdkapi/instrumentkind_string.go

@@ -0,0 +1,28 @@
+// Code generated by "stringer -type=InstrumentKind"; DO NOT EDIT.
+
+package sdkapi
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[HistogramInstrumentKind-0]
+	_ = x[GaugeObserverInstrumentKind-1]
+	_ = x[CounterInstrumentKind-2]
+	_ = x[UpDownCounterInstrumentKind-3]
+	_ = x[CounterObserverInstrumentKind-4]
+	_ = x[UpDownCounterObserverInstrumentKind-5]
+}
+
+const _InstrumentKind_name = "HistogramInstrumentKindGaugeObserverInstrumentKindCounterInstrumentKindUpDownCounterInstrumentKindCounterObserverInstrumentKindUpDownCounterObserverInstrumentKind"
+
+var _InstrumentKind_index = [...]uint8{0, 23, 50, 71, 98, 127, 162}
+
+func (i InstrumentKind) String() string {
+	if i < 0 || i >= InstrumentKind(len(_InstrumentKind_index)-1) {
+		return "InstrumentKind(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+	return _InstrumentKind_name[_InstrumentKind_index[i]:_InstrumentKind_index[i+1]]
+}

vendor/go.opentelemetry.io/otel/metric/sdkapi/noop.go

@@ -0,0 +1,66 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package sdkapi // import "go.opentelemetry.io/otel/metric/sdkapi"
+
+import (
+	"context"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric/number"
+)
+
+type noopInstrument struct {
+	descriptor Descriptor
+}
+type noopSyncInstrument struct{ noopInstrument }
+type noopAsyncInstrument struct{ noopInstrument }
+
+var _ SyncImpl = noopSyncInstrument{}
+var _ AsyncImpl = noopAsyncInstrument{}
+
+// NewNoopSyncInstrument returns a No-op implementation of the
+// synchronous instrument interface.
+func NewNoopSyncInstrument() SyncImpl {
+	return noopSyncInstrument{
+		noopInstrument{
+			descriptor: Descriptor{
+				instrumentKind: CounterInstrumentKind,
+			},
+		},
+	}
+}
+
+// NewNoopAsyncInstrument returns a No-op implementation of the
+// asynchronous instrument interface.
+func NewNoopAsyncInstrument() AsyncImpl {
+	return noopAsyncInstrument{
+		noopInstrument{
+			descriptor: Descriptor{
+				instrumentKind: CounterObserverInstrumentKind,
+			},
+		},
+	}
+}
+
+func (noopInstrument) Implementation() interface{} {
+	return nil
+}
+
+func (n noopInstrument) Descriptor() Descriptor {
+	return n.descriptor
+}
+
+func (noopSyncInstrument) RecordOne(context.Context, number.Number, []attribute.KeyValue) {
+}

vendor/go.opentelemetry.io/otel/metric/sdkapi/sdkapi.go

@@ -0,0 +1,159 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package sdkapi // import "go.opentelemetry.io/otel/metric/sdkapi"
+
+import (
+	"context"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric/number"
+)
+
+// MeterImpl is the interface an SDK must implement to supply a Meter
+// implementation.
+type MeterImpl interface {
+	// RecordBatch atomically records a batch of measurements.
+	RecordBatch(ctx context.Context, labels []attribute.KeyValue, measurement ...Measurement)
+
+	// NewSyncInstrument returns a newly constructed
+	// synchronous instrument implementation or an error, should
+	// one occur.
+	NewSyncInstrument(descriptor Descriptor) (SyncImpl, error)
+
+	// NewAsyncInstrument returns a newly constructed
+	// asynchronous instrument implementation or an error, should
+	// one occur.
+	NewAsyncInstrument(
+		descriptor Descriptor,
+		runner AsyncRunner,
+	) (AsyncImpl, error)
+}
+
+// InstrumentImpl is a common interface for synchronous and
+// asynchronous instruments.
+type InstrumentImpl interface {
+	// Implementation returns the underlying implementation of the
+	// instrument, which allows the implementation to gain access
+	// to its own representation especially from a `Measurement`.
+	Implementation() interface{}
+
+	// Descriptor returns a copy of the instrument's Descriptor.
+	Descriptor() Descriptor
+}
+
+// SyncImpl is the implementation-level interface to a generic
+// synchronous instrument (e.g., Histogram and Counter instruments).
+type SyncImpl interface {
+	InstrumentImpl
+
+	// RecordOne captures a single synchronous metric event.
+	RecordOne(ctx context.Context, number number.Number, labels []attribute.KeyValue)
+}
+
+// AsyncImpl is an implementation-level interface to an
+// asynchronous instrument (e.g., Observer instruments).
+type AsyncImpl interface {
+	InstrumentImpl
+}
+
+// AsyncRunner is expected to convert into an AsyncSingleRunner or an
+// AsyncBatchRunner.  SDKs will encounter an error if the AsyncRunner
+// does not satisfy one of these interfaces.
+type AsyncRunner interface {
+	// AnyRunner is a non-exported method with no functional use
+	// other than to make this a non-empty interface.
+	AnyRunner()
+}
+
+// AsyncSingleRunner is an interface implemented by single-observer
+// callbacks.
+type AsyncSingleRunner interface {
+	// Run accepts a single instrument and function for capturing
+	// observations of that instrument.  Each call to the function
+	// receives one captured observation.  (The function accepts
+	// multiple observations so the same implementation can be
+	// used for batch runners.)
+	Run(ctx context.Context, single AsyncImpl, capture func([]attribute.KeyValue, ...Observation))
+
+	AsyncRunner
+}
+
+// AsyncBatchRunner is an interface implemented by batch-observer
+// callbacks.
+type AsyncBatchRunner interface {
+	// Run accepts a function for capturing observations of
+	// multiple instruments.
+	Run(ctx context.Context, capture func([]attribute.KeyValue, ...Observation))
+
+	AsyncRunner
+}
+
+// NewMeasurement constructs a single observation, a binding between
+// an asynchronous instrument and a number.
+func NewMeasurement(instrument SyncImpl, number number.Number) Measurement {
+	return Measurement{
+		instrument: instrument,
+		number:     number,
+	}
+}
+
+// Measurement is a low-level type used with synchronous instruments
+// as a direct interface to the SDK via `RecordBatch`.
+type Measurement struct {
+	// number needs to be aligned for 64-bit atomic operations.
+	number     number.Number
+	instrument SyncImpl
+}
+
+// SyncImpl returns the instrument that created this measurement.
+// This returns an implementation-level object for use by the SDK,
+// users should not refer to this.
+func (m Measurement) SyncImpl() SyncImpl {
+	return m.instrument
+}
+
+// Number returns a number recorded in this measurement.
+func (m Measurement) Number() number.Number {
+	return m.number
+}
+
+// NewObservation constructs a single observation, a binding between
+// an asynchronous instrument and a number.
+func NewObservation(instrument AsyncImpl, number number.Number) Observation {
+	return Observation{
+		instrument: instrument,
+		number:     number,
+	}
+}
+
+// Observation is a low-level type used with asynchronous instruments
+// as a direct interface to the SDK via `BatchObserver`.
+type Observation struct {
+	// number needs to be aligned for 64-bit atomic operations.
+	number     number.Number
+	instrument AsyncImpl
+}
+
+// AsyncImpl returns the instrument that created this observation.
+// This returns an implementation-level object for use by the SDK,
+// users should not refer to this.
+func (m Observation) AsyncImpl() AsyncImpl {
+	return m.instrument
+}
+
+// Number returns a number recorded in this observation.
+func (m Observation) Number() number.Number {
+	return m.number
+}

vendor/go.opentelemetry.io/otel/metric/unit/doc.go

@@ -0,0 +1,20 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package unit provides units.
+//
+// This package is currently in a pre-GA phase. Backwards incompatible changes
+// may be introduced in subsequent minor version releases as we work to track
+// the evolving OpenTelemetry specification and user feedback.
+package unit // import "go.opentelemetry.io/otel/metric/unit"

vendor/go.opentelemetry.io/otel/metric/unit/unit.go

@@ -0,0 +1,24 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package unit // import "go.opentelemetry.io/otel/metric/unit"
+
+type Unit string
+
+// Units defined by OpenTelemetry.
+const (
+	Dimensionless Unit = "1"
+	Bytes         Unit = "By"
+	Milliseconds  Unit = "ms"
+)