Golang promise.Go函数代码示例

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
}