package runconfig import ( "fmt" "io" "io/ioutil" "strings" "github.com/docker/docker/pkg/broadcaster" "github.com/docker/docker/pkg/ioutils" ) // StreamConfig holds information about I/O streams managed together. // // streamConfig.StdinPipe returns a WriteCloser which can be used to feed data // to the standard input of the streamConfig's active process. // streamConfig.StdoutPipe and streamConfig.StderrPipe each return a ReadCloser // which can be used to retrieve the standard output (and error) generated // by the container's active process. The output (and error) are actually // copied and delivered to all StdoutPipe and StderrPipe consumers, using // a kind of "broadcaster". type StreamConfig struct { stdout *broadcaster.Unbuffered stderr *broadcaster.Unbuffered stdin io.ReadCloser stdinPipe io.WriteCloser } // NewStreamConfig creates a stream config and initializes // the standard err and standard out to new unbuffered broadcasters. func NewStreamConfig() *StreamConfig { return &StreamConfig{ stderr: new(broadcaster.Unbuffered), stdout: new(broadcaster.Unbuffered), } } // Stdout returns the standard output in the configuration. func (streamConfig *StreamConfig) Stdout() *broadcaster.Unbuffered { return streamConfig.stdout } // Stderr returns the standard error in the configuration. func (streamConfig *StreamConfig) Stderr() *broadcaster.Unbuffered { return streamConfig.stderr } // Stdin returns the standard input in the configuration. func (streamConfig *StreamConfig) Stdin() io.ReadCloser { return streamConfig.stdin } // StdinPipe returns an input writer pipe as an io.WriteCloser. func (streamConfig *StreamConfig) StdinPipe() io.WriteCloser { return streamConfig.stdinPipe } // StdoutPipe creates a new io.ReadCloser with an empty bytes pipe. // It adds this new out pipe to the Stdout broadcaster. func (streamConfig *StreamConfig) StdoutPipe() io.ReadCloser { bytesPipe := ioutils.NewBytesPipe(nil) streamConfig.stdout.Add(bytesPipe) return bytesPipe } // StderrPipe creates a new io.ReadCloser with an empty bytes pipe. // It adds this new err pipe to the Stderr broadcaster. func (streamConfig *StreamConfig) StderrPipe() io.ReadCloser { bytesPipe := ioutils.NewBytesPipe(nil) streamConfig.stderr.Add(bytesPipe) return bytesPipe } // NewInputPipes creates new pipes for both standard inputs, Stdin and StdinPipe. func (streamConfig *StreamConfig) NewInputPipes() { streamConfig.stdin, streamConfig.stdinPipe = io.Pipe() } // NewNopInputPipe creates a new input pipe that will silently drop all messages in the input. func (streamConfig *StreamConfig) NewNopInputPipe() { streamConfig.stdinPipe = ioutils.NopWriteCloser(ioutil.Discard) } // CloseStreams ensures that the configured streams are properly closed. func (streamConfig *StreamConfig) CloseStreams() error { var errors []string if streamConfig.stdin != nil { if err := streamConfig.stdin.Close(); err != nil { errors = append(errors, fmt.Sprintf("error close stdin: %s", err)) } } if err := streamConfig.stdout.Clean(); err != nil { errors = append(errors, fmt.Sprintf("error close stdout: %s", err)) } if err := streamConfig.stderr.Clean(); err != nil { errors = append(errors, fmt.Sprintf("error close stderr: %s", err)) } if len(errors) > 0 { return fmt.Errorf(strings.Join(errors, "\n")) } return nil }