DockerCLI/vendor/google.golang.org/grpc/internal/resolver/unix/unix.go

79 lines
2.2 KiB
Go

/*
*
* Copyright 2020 gRPC 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 unix implements a resolver for unix targets.
package unix
import (
"fmt"
"google.golang.org/grpc/internal/transport/networktype"
"google.golang.org/grpc/resolver"
)
const unixScheme = "unix"
const unixAbstractScheme = "unix-abstract"
type builder struct {
scheme string
}
func (b *builder) Build(target resolver.Target, cc resolver.ClientConn, _ resolver.BuildOptions) (resolver.Resolver, error) {
if target.URL.Host != "" {
return nil, fmt.Errorf("invalid (non-empty) authority: %v", target.URL.Host)
}
// gRPC was parsing the dial target manually before PR #4817, and we
// switched to using url.Parse() in that PR. To avoid breaking existing
// resolver implementations we ended up stripping the leading "/" from the
// endpoint. This obviously does not work for the "unix" scheme. Hence we
// end up using the parsed URL instead.
endpoint := target.URL.Path
if endpoint == "" {
endpoint = target.URL.Opaque
}
addr := resolver.Address{Addr: endpoint}
if b.scheme == unixAbstractScheme {
// We can not prepend \0 as c++ gRPC does, as in Golang '@' is used to signify we do
// not want trailing \0 in address.
addr.Addr = "@" + addr.Addr
}
cc.UpdateState(resolver.State{Addresses: []resolver.Address{networktype.Set(addr, "unix")}})
return &nopResolver{}, nil
}
func (b *builder) Scheme() string {
return b.scheme
}
func (b *builder) OverrideAuthority(resolver.Target) string {
return "localhost"
}
type nopResolver struct {
}
func (*nopResolver) ResolveNow(resolver.ResolveNowOptions) {}
func (*nopResolver) Close() {}
func init() {
resolver.Register(&builder{scheme: unixScheme})
resolver.Register(&builder{scheme: unixAbstractScheme})
}