Example #1
0
func waitExitOrRemoved(dockerCli *client.DockerCli, ctx context.Context, containerID string, waitRemove bool) (chan int, error) {
	if len(containerID) == 0 {
		// containerID can never be empty
		panic("Internal Error: waitExitOrRemoved needs a containerID as parameter")
	}

	statusChan := make(chan int)
	exitCode := 125

	eventProcessor := func(e events.Message, err error) error {
		if err != nil {
			statusChan <- exitCode
			return fmt.Errorf("failed to decode event: %v", err)
		}

		stopProcessing := false
		switch e.Status {
		case "die":
			if v, ok := e.Actor.Attributes["exitCode"]; ok {
				code, cerr := strconv.Atoi(v)
				if cerr != nil {
					logrus.Errorf("failed to convert exitcode '%q' to int: %v", v, cerr)
				} else {
					exitCode = code
				}
			}
			if !waitRemove {
				stopProcessing = true
			}
		case "detach":
			exitCode = 0
			stopProcessing = true
		case "destroy":
			stopProcessing = true
		}

		if stopProcessing {
			statusChan <- exitCode
			// stop the loop processing
			return fmt.Errorf("done")
		}

		return nil
	}

	// Get events via Events API
	f := filters.NewArgs()
	f.Add("type", "container")
	f.Add("container", containerID)
	options := types.EventsOptions{
		Filters: f,
	}
	resBody, err := dockerCli.Client().Events(ctx, options)
	if err != nil {
		return nil, fmt.Errorf("can't get events from daemon: %v", err)
	}

	go system.DecodeEvents(resBody, eventProcessor)

	return statusChan, nil
}
Example #2
0
// runStats displays a live stream of resource usage statistics for one or more containers.
// This shows real-time information on CPU usage, memory usage, and network I/O.
func runStats(dockerCli *client.DockerCli, opts *statsOptions) error {
	showAll := len(opts.containers) == 0
	closeChan := make(chan error)

	ctx := context.Background()

	// monitorContainerEvents watches for container creation and removal (only
	// used when calling `docker stats` without arguments).
	monitorContainerEvents := func(started chan<- struct{}, c chan events.Message) {
		f := filters.NewArgs()
		f.Add("type", "container")
		options := types.EventsOptions{
			Filters: f,
		}
		resBody, err := dockerCli.Client().Events(ctx, options)
		// Whether we successfully subscribed to events or not, we can now
		// unblock the main goroutine.
		close(started)
		if err != nil {
			closeChan <- err
			return
		}
		defer resBody.Close()

		system.DecodeEvents(resBody, func(event events.Message, err error) error {
			if err != nil {
				closeChan <- err
				return nil
			}
			c <- event
			return nil
		})
	}

	// waitFirst is a WaitGroup to wait first stat data's reach for each container
	waitFirst := &sync.WaitGroup{}

	cStats := stats{}
	// getContainerList simulates creation event for all previously existing
	// containers (only used when calling `docker stats` without arguments).
	getContainerList := func() {
		options := types.ContainerListOptions{
			All: opts.all,
		}
		cs, err := dockerCli.Client().ContainerList(ctx, options)
		if err != nil {
			closeChan <- err
		}
		for _, container := range cs {
			s := &containerStats{Name: container.ID[:12]}
			if cStats.add(s) {
				waitFirst.Add(1)
				go s.Collect(ctx, dockerCli.Client(), !opts.noStream, waitFirst)
			}
		}
	}

	if showAll {
		// If no names were specified, start a long running goroutine which
		// monitors container events. We make sure we're subscribed before
		// retrieving the list of running containers to avoid a race where we
		// would "miss" a creation.
		started := make(chan struct{})
		eh := system.InitEventHandler()
		eh.Handle("create", func(e events.Message) {
			if opts.all {
				s := &containerStats{Name: e.ID[:12]}
				if cStats.add(s) {
					waitFirst.Add(1)
					go s.Collect(ctx, dockerCli.Client(), !opts.noStream, waitFirst)
				}
			}
		})

		eh.Handle("start", func(e events.Message) {
			s := &containerStats{Name: e.ID[:12]}
			if cStats.add(s) {
				waitFirst.Add(1)
				go s.Collect(ctx, dockerCli.Client(), !opts.noStream, waitFirst)
			}
		})

		eh.Handle("die", func(e events.Message) {
			if !opts.all {
				cStats.remove(e.ID[:12])
			}
		})

		eventChan := make(chan events.Message)
		go eh.Watch(eventChan)
		go monitorContainerEvents(started, eventChan)
		defer close(eventChan)
		<-started

		// Start a short-lived goroutine to retrieve the initial list of
		// containers.
		getContainerList()
	} else {
		// Artificially send creation events for the containers we were asked to
		// monitor (same code path than we use when monitoring all containers).
		for _, name := range opts.containers {
			s := &containerStats{Name: name}
			if cStats.add(s) {
				waitFirst.Add(1)
				go s.Collect(ctx, dockerCli.Client(), !opts.noStream, waitFirst)
			}
		}

		// We don't expect any asynchronous errors: closeChan can be closed.
		close(closeChan)

		// Do a quick pause to detect any error with the provided list of
		// container names.
		time.Sleep(1500 * time.Millisecond)
		var errs []string
		cStats.mu.Lock()
		for _, c := range cStats.cs {
			c.mu.Lock()
			if c.err != nil {
				errs = append(errs, fmt.Sprintf("%s: %v", c.Name, c.err))
			}
			c.mu.Unlock()
		}
		cStats.mu.Unlock()
		if len(errs) > 0 {
			return fmt.Errorf("%s", strings.Join(errs, ", "))
		}
	}

	// before print to screen, make sure each container get at least one valid stat data
	waitFirst.Wait()

	w := tabwriter.NewWriter(dockerCli.Out(), 20, 1, 3, ' ', 0)
	printHeader := func() {
		if !opts.noStream {
			fmt.Fprint(dockerCli.Out(), "\033[2J")
			fmt.Fprint(dockerCli.Out(), "\033[H")
		}
		io.WriteString(w, "CONTAINER\tCPU %\tMEM USAGE / LIMIT\tMEM %\tNET I/O\tBLOCK I/O\tPIDS\n")
	}

	for range time.Tick(500 * time.Millisecond) {
		printHeader()
		cStats.mu.Lock()
		for _, s := range cStats.cs {
			if err := s.Display(w); err != nil && !opts.noStream {
				logrus.Debugf("stats: got error for %s: %v", s.Name, err)
			}
		}
		cStats.mu.Unlock()
		w.Flush()
		if opts.noStream {
			break
		}
		select {
		case err, ok := <-closeChan:
			if ok {
				if err != nil {
					// this is suppressing "unexpected EOF" in the cli when the
					// daemon restarts so it shutdowns cleanly
					if err == io.ErrUnexpectedEOF {
						return nil
					}
					return err
				}
			}
		default:
			// just skip
		}
	}
	return nil
}
Example #3
0
func waitExitOrRemoved(dockerCli *client.DockerCli, ctx context.Context, containerID string, waitRemove bool, since time.Time) (int, error) {
	if len(containerID) == 0 {
		// containerID can never be empty
		panic("Internal Error: waitExitOrRemoved needs a containerID as parameter")
	}

	var exitCode int
	exitChan := make(chan struct{})
	detachChan := make(chan struct{})
	destroyChan := make(chan struct{})

	// Start watch events
	eh := system.InitEventHandler()
	eh.Handle("die", func(e events.Message) {
		if len(e.Actor.Attributes) > 0 {
			for k, v := range e.Actor.Attributes {
				if k == "exitCode" {
					var err error
					if exitCode, err = strconv.Atoi(v); err != nil {
						logrus.Errorf("Can't convert %q to int: %v", v, err)
					}
					close(exitChan)
					break
				}
			}
		}
	})

	eh.Handle("detach", func(e events.Message) {
		exitCode = 0
		close(detachChan)
	})
	eh.Handle("destroy", func(e events.Message) {
		close(destroyChan)
	})

	eventChan := make(chan events.Message)
	go eh.Watch(eventChan)
	defer close(eventChan)

	// Get events via Events API
	f := filters.NewArgs()
	f.Add("type", "container")
	f.Add("container", containerID)
	options := types.EventsOptions{
		Since:   fmt.Sprintf("%d", since.Unix()),
		Filters: f,
	}
	resBody, err := dockerCli.Client().Events(ctx, options)
	if err != nil {
		return -1, fmt.Errorf("can't get events from daemon: %v", err)
	}
	defer resBody.Close()

	go system.DecodeEvents(resBody, func(event events.Message, err error) error {
		if err != nil {
			return nil
		}
		eventChan <- event
		return nil
	})

	if waitRemove {
		select {
		case <-destroyChan:
			return exitCode, nil
		case <-detachChan:
			return 0, nil
		}
	} else {
		select {
		case <-exitChan:
			return exitCode, nil
		case <-detachChan:
			return 0, nil
		}
	}
}