func (container *Container) waitForStart() error {
	if container.Config.MonitorDriver != MonitorExternal {
		container.monitor = newContainerMonitor(container, container.hostConfig.RestartPolicy)

		// block until we either receive an error from the initial start of the container's
		// process or until the process is running in the container
		select {
		case <-container.monitor.startSignal:
		case err := <-promise.Go(container.monitor.Start):
			return err
		}
	} else { // external monitor
		monitor := NewMonitorProxy(container, true)
		if monitor == nil {
			return fmt.Errorf("Create monitor proxy failed")
		}
		container.exMonitor = monitor
		select {
		case <-container.exMonitor.startSignal:
			pid := monitor.monitorCommand.cmd.Process.Pid
			container.monitorState.SetRunning(pid)
			log.Debugf("Monitor process has started with pid %v", pid)
			if err := container.WriteMonitorState(); err != nil {
				log.Errorf("write monitor state error: %v", err)
			}
		case err := <-promise.Go(monitor.Start):
			if err != nil {
				log.Debugf("MonitorProxy start error: %v", err)
			}
			return err
		}
	}

	return nil
}

func (b *Builder) run(c *daemon.Container) error {
	var errCh chan error
	if b.Verbose {
		errCh = promise.Go(func() error {
			// FIXME: call the 'attach' job so that daemon.Attach can be made private
			//
			// FIXME (LK4D4): Also, maybe makes sense to call "logs" job, it is like attach
			// but without hijacking for stdin. Also, with attach there can be race
			// condition because of some output already was printed before it.
			return <-b.Daemon.Attach(&c.StreamConfig, c.Config.OpenStdin, c.Config.StdinOnce, c.Config.Tty, nil, nil, b.OutStream, b.ErrStream)
		})
	}

	//start the container
	if err := c.Start(); err != nil {
		return err
	}

	if errCh != nil {
		if err := <-errCh; err != nil {
			return err
		}
	}

	// Wait for it to finish
	if ret, _ := c.WaitStop(-1 * time.Second); ret != 0 {
		err := &utils.JSONError{
			Message: fmt.Sprintf("The command %v returned a non-zero code: %d", b.Config.Cmd, ret),
			Code:    ret,
		}
		return err
	}

	return nil
}

func (container *Container) exec(ExecConfig *ExecConfig) error {
	container.Lock()
	defer container.Unlock()

	callback := func(processConfig *execdriver.ProcessConfig, pid int) {
		if processConfig.Tty {
			// The callback is called after the process Start()
			// so we are in the parent process. In TTY mode, stdin/out/err is the PtySlave
			// which we close here.
			if c, ok := processConfig.Stdout.(io.Closer); ok {
				c.Close()
			}
		}
		close(ExecConfig.waitStart)
	}

	// We use a callback here instead of a goroutine and an chan for
	// synchronization purposes
	cErr := promise.Go(func() error { return container.monitorExec(ExecConfig, callback) })

	// Exec should not return until the process is actually running
	select {
	case <-ExecConfig.waitStart:
	case err := <-cErr:
		return err
	}

	return nil
}

// Run creates, start and attach to the container based on the image name,
// the specified configuration.
// It will always create a new container.
func (c *Container) Run(ctx context.Context, configOverride *config.ServiceConfig) (int, error) {
	var (
		errCh       chan error
		out, stderr io.Writer
		in          io.ReadCloser
	)

	if configOverride.StdinOpen {
		in = os.Stdin
	}
	if configOverride.Tty {
		out = os.Stdout
	}
	if configOverride.Tty {
		stderr = os.Stderr
	}

	options := types.ContainerAttachOptions{
		Stream: true,
		Stdin:  configOverride.StdinOpen,
		Stdout: configOverride.Tty,
		Stderr: configOverride.Tty,
	}

	resp, err := c.client.ContainerAttach(ctx, c.container.ID, options)
	if err != nil {
		return -1, err
	}

	// set raw terminal
	inFd, _ := term.GetFdInfo(in)
	state, err := term.SetRawTerminal(inFd)
	if err != nil {
		return -1, err
	}
	// restore raw terminal
	defer term.RestoreTerminal(inFd, state)
	// holdHijackedConnection (in goroutine)
	errCh = promise.Go(func() error {
		return holdHijackedConnection(configOverride.Tty, in, out, stderr, resp)
	})

	if err := c.client.ContainerStart(ctx, c.container.ID, types.ContainerStartOptions{}); err != nil {
		return -1, err
	}

	if err := <-errCh; err != nil {
		logrus.Debugf("Error hijack: %s", err)
		return -1, err
	}

	exitedContainer, err := c.client.ContainerInspect(ctx, c.container.ID)
	if err != nil {
		return -1, err
	}

	return exitedContainer.State.ExitCode, nil
}

// wait starts the container and wait until
// we either receive an error from the initial start of the container's
// process or until the process is running in the container
func (m *containerMonitor) wait() error {
	select {
	case <-m.startSignal:
	case err := <-promise.Go(m.start):
		return err
	}

	return nil
}

func (dm *DockerMonitor) Start() error {
	// block until we either receive an error from the initial start of the container's
	// process or until the process is running in the container
	select {
	case <-dm.m.startSignal:
	case err := <-promise.Go(dm.m.Start):
		return err
	}
	return nil
}

func (archiver *Archiver) CopyFileWithTar(src, dst string) (err error) {
	logrus.Debugf("CopyFileWithTar(%s, %s)", src, dst)
	srcSt, err := os.Stat(src)
	if err != nil {
		return err
	}

	if srcSt.IsDir() {
		return fmt.Errorf("Can't copy a directory")
	}

	// Clean up the trailing slash. This must be done in an operating
	// system specific manner.
	if dst[len(dst)-1] == os.PathSeparator {
		dst = filepath.Join(dst, filepath.Base(src))
	}
	// Create the holding directory if necessary
	if err := system.MkdirAll(filepath.Dir(dst), 0700); err != nil && !os.IsExist(err) {
		return err
	}

	r, w := io.Pipe()
	errC := promise.Go(func() error {
		defer w.Close()

		srcF, err := os.Open(src)
		if err != nil {
			return err
		}
		defer srcF.Close()

		hdr, err := tar.FileInfoHeader(srcSt, "")
		if err != nil {
			return err
		}
		hdr.Name = filepath.Base(dst)
		hdr.Mode = int64(chmodTarEntry(os.FileMode(hdr.Mode)))

		tw := tar.NewWriter(w)
		defer tw.Close()
		if err := tw.WriteHeader(hdr); err != nil {
			return err
		}
		if _, err := io.Copy(tw, srcF); err != nil {
			return err
		}
		return nil
	})
	defer func() {
		if er := <-errC; err != nil {
			err = er
		}
	}()
	return archiver.Untar(r, filepath.Dir(dst), nil)
}

func (container *Container) waitForStart() error {
	container.monitor = newContainerMonitor(container, container.hostConfig.RestartPolicy)

	// block until we either receive an error from the initial start of the container's
	// process or until the process is running in the container
	select {
	case <-container.monitor.startSignal:
	case err := <-promise.Go(container.monitor.Start):
		return err
	}

	return nil
}

func (archiver *Archiver) CopyFileWithTar(src, dst string) (err error) {
	log.Debugf("CopyFileWithTar(%s, %s)", src, dst)
	srcSt, err := os.Stat(src)
	if err != nil {
		return err
	}
	if srcSt.IsDir() {
		return fmt.Errorf("Can't copy a directory")
	}
	// Clean up the trailing /
	if dst[len(dst)-1] == '/' {
		dst = path.Join(dst, filepath.Base(src))
	}
	// Create the holding directory if necessary
	if err := os.MkdirAll(filepath.Dir(dst), 0700); err != nil && !os.IsExist(err) {
		return err
	}

	r, w := io.Pipe()
	errC := promise.Go(func() error {
		defer w.Close()

		srcF, err := os.Open(src)
		if err != nil {
			return err
		}
		defer srcF.Close()

		hdr, err := tar.FileInfoHeader(srcSt, "")
		if err != nil {
			return err
		}
		hdr.Name = filepath.Base(dst)
		tw := tar.NewWriter(w)
		defer tw.Close()
		if err := tw.WriteHeader(hdr); err != nil {
			return err
		}
		if _, err := io.Copy(tw, srcF); err != nil {
			return err
		}
		return nil
	})
	defer func() {
		if er := <-errC; err != nil {
			err = er
		}
	}()
	return archiver.Untar(r, filepath.Dir(dst), nil)
}

func (cli *HyperClient) hijackRequest(method, pod, tag string, v *url.Values) error {
	var (
		hijacked = make(chan io.Closer)
		errCh    chan error
	)
	// Block the return until the chan gets closed
	defer func() {
		if _, ok := <-hijacked; ok {
			fmt.Printf("Hijack did not finish (chan still open)\n")
		}
	}()

	request := fmt.Sprintf("/%s?%s", method, v.Encode())

	errCh = promise.Go(func() error {
		return cli.hijack("POST", request, true, cli.in, cli.out, cli.out, hijacked, nil, "")
	})

	if err := cli.monitorTtySize(pod, tag); err != nil {
		fmt.Printf("Monitor tty size fail for %s!\n", pod)
	}

	// Acknowledge the hijack before starting
	select {
	case closer := <-hijacked:
		// Make sure that hijack gets closed when returning. (result
		// in closing hijack chan and freeing server's goroutines.
		if closer != nil {
			defer closer.Close()
		}
	case err := <-errCh:
		if err != nil {
			fmt.Printf("Error hijack: %s", err.Error())
			return err
		}
	}

	if err := <-errCh; err != nil {
		fmt.Printf("Error hijack: %s", err.Error())
		return err
	}
	return nil
}

func (d *Daemon) containerExec(container *container.Container, ec *exec.Config) error {
	container.Lock()
	defer container.Unlock()

	callback := func(processConfig *execdriver.ProcessConfig, pid int, chOOM <-chan struct{}) error {
		if processConfig.Tty {
			// The callback is called after the process Start()
			// so we are in the parent process. In TTY mode, stdin/out/err is the PtySlave
			// which we close here.
			if c, ok := processConfig.Stdout.(io.Closer); ok {
				c.Close()
			}
		}
		ec.Close()
		return nil
	}

	// We use a callback here instead of a goroutine and an chan for
	// synchronization purposes
	cErr := promise.Go(func() error { return d.monitorExec(container, ec, callback) })
	return ec.Wait(cErr)
}

func attach(streamConfig *streamConfig, openStdin, stdinOnce, tty bool, stdin io.ReadCloser, stdout io.Writer, stderr io.Writer) chan error {
	var (
		cStdout, cStderr io.ReadCloser
		cStdin           io.WriteCloser
		wg               sync.WaitGroup
		errors           = make(chan error, 3)
	)

	if stdin != nil && openStdin {
		cStdin = streamConfig.StdinPipe()
		wg.Add(1)
	}

	if stdout != nil {
		cStdout = streamConfig.StdoutPipe()
		wg.Add(1)
	}

	if stderr != nil {
		cStderr = streamConfig.StderrPipe()
		wg.Add(1)
	}

	// Connect stdin of container to the http conn.
	go func() {
		if stdin == nil || !openStdin {
			return
		}
		logrus.Debugf("attach: stdin: begin")
		defer func() {
			if stdinOnce && !tty {
				cStdin.Close()
			} else {
				// No matter what, when stdin is closed (io.Copy unblock), close stdout and stderr
				if cStdout != nil {
					cStdout.Close()
				}
				if cStderr != nil {
					cStderr.Close()
				}
			}
			wg.Done()
			logrus.Debugf("attach: stdin: end")
		}()

		var err error
		if tty {
			_, err = copyEscapable(cStdin, stdin)
		} else {
			_, err = io.Copy(cStdin, stdin)

		}
		if err == io.ErrClosedPipe {
			err = nil
		}
		if err != nil {
			logrus.Errorf("attach: stdin: %s", err)
			errors <- err
			return
		}
	}()

	attachStream := func(name string, stream io.Writer, streamPipe io.ReadCloser) {
		if stream == nil {
			return
		}
		defer func() {
			// Make sure stdin gets closed
			if stdin != nil {
				stdin.Close()
			}
			streamPipe.Close()
			wg.Done()
			logrus.Debugf("attach: %s: end", name)
		}()

		logrus.Debugf("attach: %s: begin", name)
		_, err := io.Copy(stream, streamPipe)
		if err == io.ErrClosedPipe {
			err = nil
		}
		if err != nil {
			logrus.Errorf("attach: %s: %v", name, err)
			errors <- err
		}
	}

	go attachStream("stdout", stdout, cStdout)
	go attachStream("stderr", stderr, cStderr)

	return promise.Go(func() error {
		wg.Wait()
		close(errors)
		for err := range errors {
			if err != nil {
				return err
			}
		}
		return nil
	})
//.........这里部分代码省略.........

func runStart(dockerCli *client.DockerCli, opts *startOptions) error {
	ctx, cancelFun := context.WithCancel(context.Background())

	if opts.attach || opts.openStdin {
		// We're going to attach to a container.
		// 1. Ensure we only have one container.
		if len(opts.containers) > 1 {
			return fmt.Errorf("You cannot start and attach multiple containers at once.")
		}

		// 2. Attach to the container.
		container := opts.containers[0]
		c, err := dockerCli.Client().ContainerInspect(ctx, container)
		if err != nil {
			return err
		}

		// We always use c.ID instead of container to maintain consistency during `docker start`
		if !c.Config.Tty {
			sigc := dockerCli.ForwardAllSignals(ctx, c.ID)
			defer signal.StopCatch(sigc)
		}

		if opts.detachKeys != "" {
			dockerCli.ConfigFile().DetachKeys = opts.detachKeys
		}

		options := types.ContainerAttachOptions{
			Stream:     true,
			Stdin:      opts.openStdin && c.Config.OpenStdin,
			Stdout:     true,
			Stderr:     true,
			DetachKeys: dockerCli.ConfigFile().DetachKeys,
		}

		var in io.ReadCloser

		if options.Stdin {
			in = dockerCli.In()
		}

		resp, errAttach := dockerCli.Client().ContainerAttach(ctx, c.ID, options)
		if errAttach != nil && errAttach != httputil.ErrPersistEOF {
			// ContainerAttach return an ErrPersistEOF (connection closed)
			// means server met an error and put it in Hijacked connection
			// keep the error and read detailed error message from hijacked connection
			return errAttach
		}
		defer resp.Close()
		cErr := promise.Go(func() error {
			errHijack := dockerCli.HoldHijackedConnection(ctx, c.Config.Tty, in, dockerCli.Out(), dockerCli.Err(), resp)
			if errHijack == nil {
				return errAttach
			}
			return errHijack
		})

		// 3. Start the container.
		if err := dockerCli.Client().ContainerStart(ctx, c.ID, types.ContainerStartOptions{}); err != nil {
			cancelFun()
			<-cErr
			return err
		}

		// 4. Wait for attachment to break.
		if c.Config.Tty && dockerCli.IsTerminalOut() {
			if err := dockerCli.MonitorTtySize(ctx, c.ID, false); err != nil {
				fmt.Fprintf(dockerCli.Err(), "Error monitoring TTY size: %s\n", err)
			}
		}
		if attchErr := <-cErr; attchErr != nil {
			return attchErr
		}
		_, status, err := getExitCode(dockerCli, ctx, c.ID)
		if err != nil {
			return err
		}
		if status != 0 {
			return cli.StatusError{StatusCode: status}
		}
	} else {
		// We're not going to attach to anything.
		// Start as many containers as we want.
		return startContainersWithoutAttachments(dockerCli, ctx, opts.containers)
	}

	return nil
}

//.........这里部分代码省略.........
	// We need to instantiate the chan because the select needs it. It can
	// be closed but can't be uninitialized.
	hijacked := make(chan io.Closer)
	// Block the return until the chan gets closed
	defer func() {
		logrus.Debugf("End of CmdRun(), Waiting for hijack to finish.")
		if _, ok := <-hijacked; ok {
			fmt.Fprintln(cli.err, "Hijack did not finish (chan still open)")
		}
	}()
	if config.AttachStdin || config.AttachStdout || config.AttachStderr {
		var (
			out, stderr io.Writer
			in          io.ReadCloser
			v           = url.Values{}
		)
		v.Set("stream", "1")
		if config.AttachStdin {
			v.Set("stdin", "1")
			in = cli.in
		}
		if config.AttachStdout {
			v.Set("stdout", "1")
			out = cli.out
		}
		if config.AttachStderr {
			v.Set("stderr", "1")
			if config.Tty {
				stderr = cli.out
			} else {
				stderr = cli.err
			}
		}
		errCh = promise.Go(func() error {
			return cli.hijack("POST", "/containers/"+createResponse.ID+"/attach?"+v.Encode(), config.Tty, in, out, stderr, hijacked, nil)
		})
	} else {
		close(hijacked)
	}
	// Acknowledge the hijack before starting
	select {
	case closer := <-hijacked:
		// Make sure that the hijack gets closed when returning (results
		// in closing the hijack chan and freeing server's goroutines)
		if closer != nil {
			defer closer.Close()
		}
	case err := <-errCh:
		if err != nil {
			logrus.Debugf("Error hijack: %s", err)
			return err
		}
	}

	defer func() {
		if *flAutoRemove {
			if _, _, err = readBody(cli.call("DELETE", "/containers/"+createResponse.ID+"?v=1", nil, nil)); err != nil {
				fmt.Fprintf(cli.err, "Error deleting container: %s\n", err)
			}
		}
	}()

	//start the container
	if _, _, err = readBody(cli.call("POST", "/containers/"+createResponse.ID+"/start", nil, nil)); err != nil {
		return err
	}

// CmdStart starts one or more containers.
//
// Usage: docker start [OPTIONS] CONTAINER [CONTAINER...]
func (cli *DockerCli) CmdStart(args ...string) error {
	cmd := Cli.Subcmd("start", []string{"CONTAINER [CONTAINER...]"}, Cli.DockerCommands["start"].Description, true)
	attach := cmd.Bool([]string{"a", "-attach"}, false, "Attach STDOUT/STDERR and forward signals")
	openStdin := cmd.Bool([]string{"i", "-interactive"}, false, "Attach container's STDIN")
	cmd.Require(flag.Min, 1)

	cmd.ParseFlags(args, true)

	if *attach || *openStdin {
		// We're going to attach to a container.
		// 1. Ensure we only have one container.
		if cmd.NArg() > 1 {
			return fmt.Errorf("You cannot start and attach multiple containers at once.")
		}

		// 2. Attach to the container.
		containerID := cmd.Arg(0)
		c, err := cli.client.ContainerInspect(containerID)
		if err != nil {
			return err
		}

		if !c.Config.Tty {
			sigc := cli.forwardAllSignals(containerID)
			defer signal.StopCatch(sigc)
		}

		options := types.ContainerAttachOptions{
			ContainerID: containerID,
			Stream:      true,
			Stdin:       *openStdin && c.Config.OpenStdin,
			Stdout:      true,
			Stderr:      true,
		}

		var in io.ReadCloser
		if options.Stdin {
			in = cli.in
		}

		resp, err := cli.client.ContainerAttach(options)
		if err != nil {
			return err
		}
		defer resp.Close()

		cErr := promise.Go(func() error {
			return cli.holdHijackedConnection(c.Config.Tty, in, cli.out, cli.err, resp)
		})

		// 3. Start the container.
		if err := cli.client.ContainerStart(containerID); err != nil {
			return err
		}

		// 4. Wait for attachment to break.
		if c.Config.Tty && cli.isTerminalOut {
			if err := cli.monitorTtySize(containerID, false); err != nil {
				fmt.Fprintf(cli.err, "Error monitoring TTY size: %s\n", err)
			}
		}
		if attchErr := <-cErr; attchErr != nil {
			return attchErr
		}
		_, status, err := getExitCode(cli, containerID)
		if err != nil {
			return err
		}
		if status != 0 {
			return Cli.StatusError{StatusCode: status}
		}
	} else {
		// We're not going to attach to anything.
		// Start as many containers as we want.
		return cli.startContainersWithoutAttachments(cmd.Args())
	}

	return nil
}

//.........这里部分代码省略.........
		go func() {
			defer close(waitDisplayID)
			fmt.Fprintln(stdout, createResponse.ID)
		}()
	}
	attach := config.AttachStdin || config.AttachStdout || config.AttachStderr
	if attach {
		var (
			out, cerr io.Writer
			in        io.ReadCloser
		)
		if config.AttachStdin {
			in = stdin
		}
		if config.AttachStdout {
			out = stdout
		}
		if config.AttachStderr {
			if config.Tty {
				cerr = stdout
			} else {
				cerr = stderr
			}
		}

		if opts.detachKeys != "" {
			dockerCli.ConfigFile().DetachKeys = opts.detachKeys
		}

		options := types.ContainerAttachOptions{
			Stream:     true,
			Stdin:      config.AttachStdin,
			Stdout:     config.AttachStdout,
			Stderr:     config.AttachStderr,
			DetachKeys: dockerCli.ConfigFile().DetachKeys,
		}

		resp, errAttach := client.ContainerAttach(ctx, createResponse.ID, options)
		if errAttach != nil && errAttach != httputil.ErrPersistEOF {
			// ContainerAttach returns an ErrPersistEOF (connection closed)
			// means server met an error and put it in Hijacked connection
			// keep the error and read detailed error message from hijacked connection later
			return errAttach
		}
		defer resp.Close()

		errCh = promise.Go(func() error {
			if errHijack := holdHijackedConnection(ctx, dockerCli, config.Tty, in, out, cerr, resp); errHijack != nil {
				return errHijack
			}
			return errAttach
		})
	}

	statusChan := waitExitOrRemoved(ctx, dockerCli, createResponse.ID, hostConfig.AutoRemove)

	//start the container
	if err := client.ContainerStart(ctx, createResponse.ID, types.ContainerStartOptions{}); err != nil {
		// If we have holdHijackedConnection, we should notify
		// holdHijackedConnection we are going to exit and wait
		// to avoid the terminal are not restored.
		if attach {
			cancelFun()
			<-errCh
		}

		reportError(stderr, cmdPath, err.Error(), false)
		if hostConfig.AutoRemove {
			// wait container to be removed
			<-statusChan
		}
		return runStartContainerErr(err)
	}

	if (config.AttachStdin || config.AttachStdout || config.AttachStderr) && config.Tty && dockerCli.Out().IsTerminal() {
		if err := MonitorTtySize(ctx, dockerCli, createResponse.ID, false); err != nil {
			fmt.Fprintln(stderr, "Error monitoring TTY size:", err)
		}
	}

	if errCh != nil {
		if err := <-errCh; err != nil {
			logrus.Debugf("Error hijack: %s", err)
			return err
		}
	}

	// Detached mode: wait for the id to be displayed and return.
	if !config.AttachStdout && !config.AttachStderr {
		// Detached mode
		<-waitDisplayID
		return nil
	}

	status := <-statusChan
	if status != 0 {
		return cli.StatusError{StatusCode: status}
	}
	return nil
}

// CmdExec runs a command in a running container.
//
// Usage: docker exec [OPTIONS] CONTAINER COMMAND [ARG...]
func (cli *DockerCli) CmdExec(args ...string) error {
	cmd := Cli.Subcmd("exec", []string{"CONTAINER COMMAND [ARG...]"}, Cli.DockerCommands["exec"].Description, true)
	detachKeys := cmd.String([]string{"-detach-keys"}, "", "Override the key sequence for detaching a container")

	execConfig, err := ParseExec(cmd, args)
	container := cmd.Arg(0)
	// just in case the ParseExec does not exit
	if container == "" || err != nil {
		return Cli.StatusError{StatusCode: 1}
	}

	if *detachKeys != "" {
		cli.configFile.DetachKeys = *detachKeys
	}

	// Send client escape keys
	execConfig.DetachKeys = cli.configFile.DetachKeys

	ctx := context.Background()

	response, err := cli.client.ContainerExecCreate(ctx, container, *execConfig)
	if err != nil {
		return err
	}

	execID := response.ID
	if execID == "" {
		fmt.Fprintf(cli.out, "exec ID empty")
		return nil
	}

	//Temp struct for execStart so that we don't need to transfer all the execConfig
	if !execConfig.Detach {
		if err := cli.CheckTtyInput(execConfig.AttachStdin, execConfig.Tty); err != nil {
			return err
		}
	} else {
		execStartCheck := types.ExecStartCheck{
			Detach: execConfig.Detach,
			Tty:    execConfig.Tty,
		}

		if err := cli.client.ContainerExecStart(ctx, execID, execStartCheck); err != nil {
			return err
		}
		// For now don't print this - wait for when we support exec wait()
		// fmt.Fprintf(cli.out, "%s\n", execID)
		return nil
	}

	// Interactive exec requested.
	var (
		out, stderr io.Writer
		in          io.ReadCloser
		errCh       chan error
	)

	if execConfig.AttachStdin {
		in = cli.in
	}
	if execConfig.AttachStdout {
		out = cli.out
	}
	if execConfig.AttachStderr {
		if execConfig.Tty {
			stderr = cli.out
		} else {
			stderr = cli.err
		}
	}

	resp, err := cli.client.ContainerExecAttach(ctx, execID, *execConfig)
	if err != nil {
		return err
	}
	defer resp.Close()
	errCh = promise.Go(func() error {
		return cli.HoldHijackedConnection(ctx, execConfig.Tty, in, out, stderr, resp)
	})

	if execConfig.Tty && cli.isTerminalIn {
		if err := cli.MonitorTtySize(ctx, execID, true); err != nil {
			fmt.Fprintf(cli.err, "Error monitoring TTY size: %s\n", err)
		}
	}

	if err := <-errCh; err != nil {
		logrus.Debugf("Error hijack: %s", err)
		return err
	}

	var status int
	if _, status, err = cli.getExecExitCode(ctx, execID); err != nil {
		return err
	}

	if status != 0 {
//.........这里部分代码省略.........

//.........这里部分代码省略.........
			cStdout = p
			go func() {
				log.Debugf("attach: stdout: begin")
				defer log.Debugf("attach: stdout: end")
				// If we are in StdinOnce mode, then close stdin
				if 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 {
					log.Errorf("attach: stdout: %s", err)
				}
				errors <- err
			}()
		}
	} else {
		// Point stdout of container to a no-op writer.
		go func() {
			if stdinCloser != nil {
				defer stdinCloser.Close()
			}
			if cStdout, err := streamConfig.StdoutPipe(); err != nil {
				log.Errorf("attach: stdout pipe: %s", err)
			} else {
				io.Copy(&ioutils.NopWriter{}, cStdout)
			}
		}()
	}
	if stderr != nil {
		nJobs++
		if p, err := streamConfig.StderrPipe(); err != nil {
			errors <- err
		} else {
			cStderr = p
			go func() {
				log.Debugf("attach: stderr: begin")
				defer log.Debugf("attach: stderr: end")
				// If we are in StdinOnce mode, then close stdin
				// Why are we closing stdin here and above while handling stdout?
				if 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 {
					log.Errorf("attach: stderr: %s", err)
				}
				errors <- err
			}()
		}
	} else {
		// Point stderr at a no-op writer.
		go func() {
			if stdinCloser != nil {
				defer stdinCloser.Close()
			}

			if cStderr, err := streamConfig.StderrPipe(); err != nil {
				log.Errorf("attach: stdout pipe: %s", err)
			} else {
				io.Copy(&ioutils.NopWriter{}, cStderr)
			}
		}()
	}

	return promise.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++ {
			log.Debugf("attach: waiting for job %d/%d", i+1, nJobs)
			if err := <-errors; err != nil {
				log.Errorf("attach: job %d returned error %s, aborting all jobs", i+1, err)
				return err
			}
			log.Debugf("attach: job %d completed successfully", i+1)
		}
		log.Debugf("attach: all jobs completed successfully")
		return nil
	})
}

// CopyFileWithTar emulates the behavior of the 'cp' command-line
// for a single file. It copies a regular file from path `src` to
// path `dst`, and preserves all its metadata.
func (archiver *Archiver) CopyFileWithTar(src, dst string) (err error) {
	logrus.Debugf("CopyFileWithTar(%s, %s)", src, dst)
	srcSt, err := os.Stat(src)
	if err != nil {
		return err
	}

	if srcSt.IsDir() {
		return fmt.Errorf("Can't copy a directory")
	}

	// Clean up the trailing slash. This must be done in an operating
	// system specific manner.
	if dst[len(dst)-1] == os.PathSeparator {
		dst = filepath.Join(dst, filepath.Base(src))
	}
	// Create the holding directory if necessary
	if err := system.MkdirAll(filepath.Dir(dst), 0700); err != nil {
		return err
	}

	r, w := io.Pipe()
	errC := promise.Go(func() error {
		defer w.Close()

		srcF, err := os.Open(src)
		if err != nil {
			return err
		}
		defer srcF.Close()

		hdr, err := tar.FileInfoHeader(srcSt, "")
		if err != nil {
			return err
		}
		hdr.Name = filepath.Base(dst)
		hdr.Mode = int64(chmodTarEntry(os.FileMode(hdr.Mode)))

		remappedRootUID, remappedRootGID, err := idtools.GetRootUIDGID(archiver.UIDMaps, archiver.GIDMaps)
		if err != nil {
			return err
		}

		// only perform mapping if the file being copied isn't already owned by the
		// uid or gid of the remapped root in the container
		if remappedRootUID != hdr.Uid {
			xUID, err := idtools.ToHost(hdr.Uid, archiver.UIDMaps)
			if err != nil {
				return err
			}
			hdr.Uid = xUID
		}
		if remappedRootGID != hdr.Gid {
			xGID, err := idtools.ToHost(hdr.Gid, archiver.GIDMaps)
			if err != nil {
				return err
			}
			hdr.Gid = xGID
		}

		tw := tar.NewWriter(w)
		defer tw.Close()
		if err := tw.WriteHeader(hdr); err != nil {
			return err
		}
		if _, err := io.Copy(tw, srcF); err != nil {
			return err
		}
		return nil
	})
	defer func() {
		if er := <-errC; err != nil {
			err = er
		}
	}()

	err = archiver.Untar(r, filepath.Dir(dst), nil)
	if err != nil {
		r.CloseWithError(err)
	}
	return err
}

// CmdExec runs a command in a running container.
//
// Usage: docker exec [OPTIONS] CONTAINER COMMAND [ARG...]
func (cli *DockerCli) CmdExec(args ...string) error {
	cmd := Cli.Subcmd("exec", []string{"CONTAINER COMMAND [ARG...]"}, Cli.DockerCommands["exec"].Description, true)

	execConfig, err := runconfig.ParseExec(cmd, args)
	// just in case the ParseExec does not exit
	if execConfig.Container == "" || err != nil {
		return Cli.StatusError{StatusCode: 1}
	}

	serverResp, err := cli.call("POST", "/containers/"+execConfig.Container+"/exec", execConfig, nil)
	if err != nil {
		return err
	}

	defer serverResp.body.Close()

	var response types.ContainerExecCreateResponse
	if err := json.NewDecoder(serverResp.body).Decode(&response); err != nil {
		return err
	}

	execID := response.ID

	if execID == "" {
		fmt.Fprintf(cli.out, "exec ID empty")
		return nil
	}

	//Temp struct for execStart so that we don't need to transfer all the execConfig
	execStartCheck := &types.ExecStartCheck{
		Detach: execConfig.Detach,
		Tty:    execConfig.Tty,
	}

	if !execConfig.Detach {
		if err := cli.CheckTtyInput(execConfig.AttachStdin, execConfig.Tty); err != nil {
			return err
		}
	} else {
		if _, _, err := readBody(cli.call("POST", "/exec/"+execID+"/start", execStartCheck, nil)); err != nil {
			return err
		}
		// For now don't print this - wait for when we support exec wait()
		// fmt.Fprintf(cli.out, "%s\n", execID)
		return nil
	}

	// Interactive exec requested.
	var (
		out, stderr io.Writer
		in          io.ReadCloser
		hijacked    = make(chan io.Closer)
		errCh       chan error
	)

	// Block the return until the chan gets closed
	defer func() {
		logrus.Debugf("End of CmdExec(), Waiting for hijack to finish.")
		if _, ok := <-hijacked; ok {
			fmt.Fprintln(cli.err, "Hijack did not finish (chan still open)")
		}
	}()

	if execConfig.AttachStdin {
		in = cli.in
	}
	if execConfig.AttachStdout {
		out = cli.out
	}
	if execConfig.AttachStderr {
		if execConfig.Tty {
			stderr = cli.out
		} else {
			stderr = cli.err
		}
	}
	errCh = promise.Go(func() error {
		return cli.hijack("POST", "/exec/"+execID+"/start", execConfig.Tty, in, out, stderr, hijacked, execConfig)
	})

	// Acknowledge the hijack before starting
	select {
	case closer := <-hijacked:
		// Make sure that hijack gets closed when returning. (result
		// in closing hijack chan and freeing server's goroutines.
		if closer != nil {
			defer closer.Close()
		}
	case err := <-errCh:
		if err != nil {
			logrus.Debugf("Error hijack: %s", err)
			return err
		}
	}

	if execConfig.Tty && cli.isTerminalIn {
		if err := cli.monitorTtySize(execID, true); err != nil {
//.........这里部分代码省略.........