Set APIVersion on the client, even when Ping fails

Refactor to support testing
Also add tests

Signed-off-by: Daniel Nephin <dnephin@docker.com>

cli/command/cli.go

@@ -17,6 +17,7 @@ import (
 	"github.com/docker/docker/client"
 	"github.com/docker/go-connections/sockets"
 	"github.com/docker/go-connections/tlsconfig"
+	"github.com/docker/notary"
 	"github.com/docker/notary/passphrase"
 	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
@@ -111,44 +112,53 @@ func (cli *DockerCli) Initialize(opts *cliflags.ClientOptions) error {
 	var err error
 	cli.client, err = NewAPIClientFromFlags(opts.Common, cli.configFile)
 	if tlsconfig.IsErrEncryptedKey(err) {
-		var (
-			passwd string
-			giveup bool
-		)
 		passRetriever := passphrase.PromptRetrieverWithInOut(cli.In(), cli.Out(), nil)
-
-		for attempts := 0; tlsconfig.IsErrEncryptedKey(err); attempts++ {
-			// some code and comments borrowed from notary/trustmanager/keystore.go
-			passwd, giveup, err = passRetriever("private", "encrypted TLS private", false, attempts)
-			// Check if the passphrase retriever got an error or if it is telling us to give up
-			if giveup || err != nil {
-				return errors.Wrap(err, "private key is encrypted, but could not get passphrase")
+		newClient := func(password string) (client.APIClient, error) {
+			opts.Common.TLSOptions.Passphrase = password
+			return NewAPIClientFromFlags(opts.Common, cli.configFile)
 		}
-
-			opts.Common.TLSOptions.Passphrase = passwd
-			cli.client, err = NewAPIClientFromFlags(opts.Common, cli.configFile)
+		cli.client, err = getClientWithPassword(passRetriever, newClient)
 	}
-	}
-
 	if err != nil {
 		return err
 	}
+	cli.initializeFromClient()
+	return nil
+}
 
+func (cli *DockerCli) initializeFromClient() {
 	cli.defaultVersion = cli.client.ClientVersion()
 
-	if ping, err := cli.client.Ping(context.Background()); err == nil {
+	ping, err := cli.client.Ping(context.Background())
+	if err != nil {
+		// Default to true if we fail to connect to daemon
+		cli.server = ServerInfo{HasExperimental: true}
+
+		if ping.APIVersion != "" {
+			cli.client.NegotiateAPIVersionPing(ping)
+		}
+		return
+	}
+
 	cli.server = ServerInfo{
 		HasExperimental: ping.Experimental,
 		OSType:          ping.OSType,
 	}
-
 	cli.client.NegotiateAPIVersionPing(ping)
-	} else {
-		// Default to true if we fail to connect to daemon
-		cli.server = ServerInfo{HasExperimental: true}
 }
 
-	return nil
+func getClientWithPassword(passRetriever notary.PassRetriever, newClient func(password string) (client.APIClient, error)) (client.APIClient, error) {
+	for attempts := 0; ; attempts++ {
+		passwd, giveup, err := passRetriever("private", "encrypted TLS private", false, attempts)
+		if giveup || err != nil {
+			return nil, errors.Wrap(err, "private key is encrypted, but could not get passphrase")
+		}
+
+		apiclient, err := newClient(passwd)
+		if !tlsconfig.IsErrEncryptedKey(err) {
+			return apiclient, err
+		}
+	}
 }
 
 // ServerInfo stores details about the supported features and platform of the

cli/command/cli_test.go

@@ -4,12 +4,18 @@ import (
 	"os"
 	"testing"
 
+	"crypto/x509"
+
 	"github.com/docker/cli/cli/config/configfile"
 	"github.com/docker/cli/cli/flags"
+	"github.com/docker/cli/internal/test/testutil"
 	"github.com/docker/docker/api"
+	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/client"
+	"github.com/pkg/errors"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"golang.org/x/net/context"
 )
 
 func TestNewAPIClientFromFlags(t *testing.T) {
@@ -43,7 +49,7 @@ func TestNewAPIClientFromFlagsWithAPIVersionFromEnv(t *testing.T) {
 	assert.Equal(t, customVersion, apiclient.ClientVersion())
 }
 
-// TODO: move to gotestyourself
+// TODO: use gotestyourself/env.Patch
 func patchEnvVariable(t *testing.T, key, value string) func() {
 	oldValue, ok := os.LookupEnv(key)
 	require.NoError(t, os.Setenv(key, value))
@@ -55,3 +61,138 @@ func patchEnvVariable(t *testing.T, key, value string) func() {
 		require.NoError(t, os.Setenv(key, oldValue))
 	}
 }
+
+type fakeClient struct {
+	client.Client
+	pingFunc   func() (types.Ping, error)
+	version    string
+	negotiated bool
+}
+
+func (c *fakeClient) Ping(_ context.Context) (types.Ping, error) {
+	return c.pingFunc()
+}
+
+func (c *fakeClient) ClientVersion() string {
+	return c.version
+}
+
+func (c *fakeClient) NegotiateAPIVersionPing(types.Ping) {
+	c.negotiated = true
+}
+
+func TestInitializeFromClient(t *testing.T) {
+	defaultVersion := "v1.55"
+
+	var testcases = []struct {
+		doc            string
+		pingFunc       func() (types.Ping, error)
+		expectedServer ServerInfo
+		negotiated     bool
+	}{
+		{
+			doc: "successful ping",
+			pingFunc: func() (types.Ping, error) {
+				return types.Ping{Experimental: true, OSType: "linux", APIVersion: "v1.30"}, nil
+			},
+			expectedServer: ServerInfo{HasExperimental: true, OSType: "linux"},
+			negotiated:     true,
+		},
+		{
+			doc: "failed ping, no API version",
+			pingFunc: func() (types.Ping, error) {
+				return types.Ping{}, errors.New("failed")
+			},
+			expectedServer: ServerInfo{HasExperimental: true},
+		},
+		{
+			doc: "failed ping, with API version",
+			pingFunc: func() (types.Ping, error) {
+				return types.Ping{APIVersion: "v1.33"}, errors.New("failed")
+			},
+			expectedServer: ServerInfo{HasExperimental: true},
+			negotiated:     true,
+		},
+	}
+
+	for _, testcase := range testcases {
+		t.Run(testcase.doc, func(t *testing.T) {
+			apiclient := &fakeClient{
+				pingFunc: testcase.pingFunc,
+				version:  defaultVersion,
+			}
+
+			cli := &DockerCli{client: apiclient}
+			cli.initializeFromClient()
+			assert.Equal(t, defaultVersion, cli.defaultVersion)
+			assert.Equal(t, testcase.expectedServer, cli.server)
+			assert.Equal(t, testcase.negotiated, apiclient.negotiated)
+		})
+	}
+}
+
+func TestGetClientWithPassword(t *testing.T) {
+	expected := "password"
+
+	var testcases = []struct {
+		doc             string
+		password        string
+		retrieverErr    error
+		retrieverGiveup bool
+		newClientErr    error
+		expectedErr     string
+	}{
+		{
+			doc:      "successful connect",
+			password: expected,
+		},
+		{
+			doc:             "password retriever exhausted",
+			retrieverGiveup: true,
+			retrieverErr:    errors.New("failed"),
+			expectedErr:     "private key is encrypted, but could not get passphrase",
+		},
+		{
+			doc:          "password retriever error",
+			retrieverErr: errors.New("failed"),
+			expectedErr:  "failed",
+		},
+		{
+			doc:          "newClient error",
+			newClientErr: errors.New("failed to connect"),
+			expectedErr:  "failed to connect",
+		},
+	}
+
+	for _, testcase := range testcases {
+		t.Run(testcase.doc, func(t *testing.T) {
+			passRetriever := func(_, _ string, _ bool, attempts int) (passphrase string, giveup bool, err error) {
+				// Always return an invalid pass first to test iteration
+				switch attempts {
+				case 0:
+					return "something else", false, nil
+				default:
+					return testcase.password, testcase.retrieverGiveup, testcase.retrieverErr
+				}
+			}
+
+			newClient := func(currentPassword string) (client.APIClient, error) {
+				if testcase.newClientErr != nil {
+					return nil, testcase.newClientErr
+				}
+				if currentPassword == expected {
+					return &client.Client{}, nil
+				}
+				return &client.Client{}, x509.IncorrectPasswordError
+			}
+
+			_, err := getClientWithPassword(passRetriever, newClient)
+			if testcase.expectedErr != "" {
+				testutil.ErrorContains(t, err, testcase.expectedErr)
+				return
+			}
+
+			assert.NoError(t, err)
+		})
+	}
+}