diff options
Diffstat (limited to 'vendor/k8s.io/client-go/tools/remotecommand/v2.go')
-rw-r--r-- | vendor/k8s.io/client-go/tools/remotecommand/v2.go | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/vendor/k8s.io/client-go/tools/remotecommand/v2.go b/vendor/k8s.io/client-go/tools/remotecommand/v2.go new file mode 100644 index 000000000..95346a439 --- /dev/null +++ b/vendor/k8s.io/client-go/tools/remotecommand/v2.go @@ -0,0 +1,195 @@ +/* +Copyright 2015 The Kubernetes 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 remotecommand + +import ( + "fmt" + "io" + "io/ioutil" + "net/http" + "sync" + + "k8s.io/apimachinery/pkg/util/runtime" + "k8s.io/client-go/pkg/api/v1" +) + +// streamProtocolV2 implements version 2 of the streaming protocol for attach +// and exec. The original streaming protocol was metav1. As a result, this +// version is referred to as version 2, even though it is the first actual +// numbered version. +type streamProtocolV2 struct { + StreamOptions + + errorStream io.Reader + remoteStdin io.ReadWriteCloser + remoteStdout io.Reader + remoteStderr io.Reader +} + +var _ streamProtocolHandler = &streamProtocolV2{} + +func newStreamProtocolV2(options StreamOptions) streamProtocolHandler { + return &streamProtocolV2{ + StreamOptions: options, + } +} + +func (p *streamProtocolV2) createStreams(conn streamCreator) error { + var err error + headers := http.Header{} + + // set up error stream + headers.Set(v1.StreamType, v1.StreamTypeError) + p.errorStream, err = conn.CreateStream(headers) + if err != nil { + return err + } + + // set up stdin stream + if p.Stdin != nil { + headers.Set(v1.StreamType, v1.StreamTypeStdin) + p.remoteStdin, err = conn.CreateStream(headers) + if err != nil { + return err + } + } + + // set up stdout stream + if p.Stdout != nil { + headers.Set(v1.StreamType, v1.StreamTypeStdout) + p.remoteStdout, err = conn.CreateStream(headers) + if err != nil { + return err + } + } + + // set up stderr stream + if p.Stderr != nil && !p.Tty { + headers.Set(v1.StreamType, v1.StreamTypeStderr) + p.remoteStderr, err = conn.CreateStream(headers) + if err != nil { + return err + } + } + return nil +} + +func (p *streamProtocolV2) copyStdin() { + if p.Stdin != nil { + var once sync.Once + + // copy from client's stdin to container's stdin + go func() { + defer runtime.HandleCrash() + + // if p.stdin is noninteractive, p.g. `echo abc | kubectl exec -i <pod> -- cat`, make sure + // we close remoteStdin as soon as the copy from p.stdin to remoteStdin finishes. Otherwise + // the executed command will remain running. + defer once.Do(func() { p.remoteStdin.Close() }) + + if _, err := io.Copy(p.remoteStdin, p.Stdin); err != nil { + runtime.HandleError(err) + } + }() + + // read from remoteStdin until the stream is closed. this is essential to + // be able to exit interactive sessions cleanly and not leak goroutines or + // hang the client's terminal. + // + // TODO we aren't using go-dockerclient any more; revisit this to determine if it's still + // required by engine-api. + // + // go-dockerclient's current hijack implementation + // (https://github.com/fsouza/go-dockerclient/blob/89f3d56d93788dfe85f864a44f85d9738fca0670/client.go#L564) + // waits for all three streams (stdin/stdout/stderr) to finish copying + // before returning. When hijack finishes copying stdout/stderr, it calls + // Close() on its side of remoteStdin, which allows this copy to complete. + // When that happens, we must Close() on our side of remoteStdin, to + // allow the copy in hijack to complete, and hijack to return. + go func() { + defer runtime.HandleCrash() + defer once.Do(func() { p.remoteStdin.Close() }) + + // this "copy" doesn't actually read anything - it's just here to wait for + // the server to close remoteStdin. + if _, err := io.Copy(ioutil.Discard, p.remoteStdin); err != nil { + runtime.HandleError(err) + } + }() + } +} + +func (p *streamProtocolV2) copyStdout(wg *sync.WaitGroup) { + if p.Stdout == nil { + return + } + + wg.Add(1) + go func() { + defer runtime.HandleCrash() + defer wg.Done() + + if _, err := io.Copy(p.Stdout, p.remoteStdout); err != nil { + runtime.HandleError(err) + } + }() +} + +func (p *streamProtocolV2) copyStderr(wg *sync.WaitGroup) { + if p.Stderr == nil || p.Tty { + return + } + + wg.Add(1) + go func() { + defer runtime.HandleCrash() + defer wg.Done() + + if _, err := io.Copy(p.Stderr, p.remoteStderr); err != nil { + runtime.HandleError(err) + } + }() +} + +func (p *streamProtocolV2) stream(conn streamCreator) error { + if err := p.createStreams(conn); err != nil { + return err + } + + // now that all the streams have been created, proceed with reading & copying + + errorChan := watchErrorStream(p.errorStream, &errorDecoderV2{}) + + p.copyStdin() + + var wg sync.WaitGroup + p.copyStdout(&wg) + p.copyStderr(&wg) + + // we're waiting for stdout/stderr to finish copying + wg.Wait() + + // waits for errorStream to finish reading with an error or nil + return <-errorChan +} + +// errorDecoderV2 interprets the error channel data as plain text. +type errorDecoderV2 struct{} + +func (d *errorDecoderV2) decode(message []byte) error { + return fmt.Errorf("error executing remote command: %s", message) +} |