package daemon import ( "encoding/json" "fmt" "io" "os" "time" "github.com/docker/docker/engine" "github.com/docker/docker/utils" ) func (daemon *Daemon) ContainerAttach(job *engine.Job) engine.Status { if len(job.Args) != 1 { return job.Errorf("Usage: %s CONTAINER\n", job.Name) } var ( name = job.Args[0] logs = job.GetenvBool("logs") stream = job.GetenvBool("stream") stdin = job.GetenvBool("stdin") stdout = job.GetenvBool("stdout") stderr = job.GetenvBool("stderr") ) container := daemon.Get(name) if container == nil { return job.Errorf("No such container: %s", name) } //logs if logs { cLog, err := container.ReadLog("json") if err != nil && os.IsNotExist(err) { // Legacy logs utils.Debugf("Old logs format") if stdout { cLog, err := container.ReadLog("stdout") if err != nil { utils.Errorf("Error reading logs (stdout): %s", err) } else if _, err := io.Copy(job.Stdout, cLog); err != nil { utils.Errorf("Error streaming logs (stdout): %s", err) } } if stderr { cLog, err := container.ReadLog("stderr") if err != nil { utils.Errorf("Error reading logs (stderr): %s", err) } else if _, err := io.Copy(job.Stderr, cLog); err != nil { utils.Errorf("Error streaming logs (stderr): %s", err) } } } else if err != nil { utils.Errorf("Error reading logs (json): %s", err) } else { dec := json.NewDecoder(cLog) for { l := &utils.JSONLog{} if err := dec.Decode(l); err == io.EOF { break } else if err != nil { utils.Errorf("Error streaming logs: %s", err) break } if l.Stream == "stdout" && stdout { fmt.Fprintf(job.Stdout, "%s", l.Log) } if l.Stream == "stderr" && stderr { fmt.Fprintf(job.Stderr, "%s", l.Log) } } } } //stream if stream { var ( cStdin io.ReadCloser cStdout, cStderr io.Writer cStdinCloser io.Closer ) if stdin { r, w := io.Pipe() go func() { defer w.Close() defer utils.Debugf("Closing buffered stdin pipe") io.Copy(w, job.Stdin) }() cStdin = r cStdinCloser = job.Stdin } if stdout { cStdout = job.Stdout } if stderr { cStderr = job.Stderr } <-daemon.Attach(container, cStdin, cStdinCloser, cStdout, cStderr) // If we are in stdinonce mode, wait for the process to end // otherwise, simply return if container.Config.StdinOnce && !container.Config.Tty { container.State.WaitStop(-1 * time.Second) } } return engine.StatusOK } // FIXME: this should be private, and every outside subsystem // should go through the "container_attach" job. But that would require // that job to be properly documented, as well as the relationship betweem // Attach and ContainerAttach. // // This method is in use by builder/builder.go. func (daemon *Daemon) Attach(container *Container, stdin io.ReadCloser, stdinCloser io.Closer, stdout io.Writer, stderr io.Writer) chan error { var ( cStdout, cStderr io.ReadCloser nJobs int errors = make(chan error, 3) ) if stdin != nil && container.Config.OpenStdin { nJobs += 1 if cStdin, err := container.StdinPipe(); err != nil { errors <- err } else { go func() { utils.Debugf("attach: stdin: begin") defer utils.Debugf("attach: stdin: end") // No matter what, when stdin is closed (io.Copy unblock), close stdout and stderr if container.Config.StdinOnce && !container.Config.Tty { defer cStdin.Close() } else { defer func() { if cStdout != nil { cStdout.Close() } if cStderr != nil { cStderr.Close() } }() } if container.Config.Tty { _, err = utils.CopyEscapable(cStdin, stdin) } else { _, err = io.Copy(cStdin, stdin) } if err == io.ErrClosedPipe { err = nil } if err != nil { utils.Errorf("attach: stdin: %s", err) } errors <- err }() } } if stdout != nil { nJobs += 1 if p, err := container.StdoutPipe(); err != nil { errors <- err } else { cStdout = p go func() { utils.Debugf("attach: stdout: begin") defer utils.Debugf("attach: stdout: end") // If we are in StdinOnce mode, then close stdin if container.Config.StdinOnce && stdin != nil { defer stdin.Close() } if stdinCloser != nil { defer stdinCloser.Close() } _, err := io.Copy(stdout, cStdout) if err == io.ErrClosedPipe { err = nil } if err != nil { utils.Errorf("attach: stdout: %s", err) } errors <- err }() } } else { go func() { if stdinCloser != nil { defer stdinCloser.Close() } if cStdout, err := container.StdoutPipe(); err != nil { utils.Errorf("attach: stdout pipe: %s", err) } else { io.Copy(&utils.NopWriter{}, cStdout) } }() } if stderr != nil { nJobs += 1 if p, err := container.StderrPipe(); err != nil { errors <- err } else { cStderr = p go func() { utils.Debugf("attach: stderr: begin") defer utils.Debugf("attach: stderr: end") // If we are in StdinOnce mode, then close stdin if container.Config.StdinOnce && stdin != nil { defer stdin.Close() } if stdinCloser != nil { defer stdinCloser.Close() } _, err := io.Copy(stderr, cStderr) if err == io.ErrClosedPipe { err = nil } if err != nil { utils.Errorf("attach: stderr: %s", err) } errors <- err }() } } else { go func() { if stdinCloser != nil { defer stdinCloser.Close() } if cStderr, err := container.StderrPipe(); err != nil { utils.Errorf("attach: stdout pipe: %s", err) } else { io.Copy(&utils.NopWriter{}, cStderr) } }() } return utils.Go(func() error { defer func() { if cStdout != nil { cStdout.Close() } if cStderr != nil { cStderr.Close() } }() // FIXME: how to clean up the stdin goroutine without the unwanted side effect // of closing the passed stdin? Add an intermediary io.Pipe? for i := 0; i < nJobs; i += 1 { utils.Debugf("attach: waiting for job %d/%d", i+1, nJobs) if err := <-errors; err != nil { utils.Errorf("attach: job %d returned error %s, aborting all jobs", i+1, err) return err } utils.Debugf("attach: job %d completed successfully", i+1) } utils.Debugf("attach: all jobs completed successfully") return nil }) }