func()

in daemon/daemon.go [234:407]

• 139 lines of code
• 42 McCabe index (conditional complexity)

func (daemon *Daemon) restore() error {
	var (
		debug         = utils.IsDebugEnabled()
		currentDriver = daemon.GraphDriverName()
		containers    = make(map[string]*container.Container)
	)

	if !debug {
		logrus.Info("Loading containers: start.")
	}
	dir, err := ioutil.ReadDir(daemon.repository)
	if err != nil {
		return err
	}

	for _, v := range dir {
		id := v.Name()
		container, err := daemon.load(id)
		if !debug && logrus.GetLevel() == logrus.InfoLevel {
			fmt.Print(".")
		}
		if err != nil {
			logrus.Errorf("Failed to load container %v: %v", id, err)
			continue
		}

		// Ignore the container if it does not support the current driver being used by the graph
		if (container.Driver == "" && currentDriver == "aufs") || container.Driver == currentDriver {
			rwlayer, err := daemon.layerStore.GetRWLayer(container.ID)
			if err != nil {
				logrus.Errorf("Failed to load container mount %v: %v", id, err)
				continue
			}
			container.RWLayer = rwlayer
			logrus.Debugf("Loaded container %v", container.ID)

			containers[container.ID] = container
		} else {
			logrus.Debugf("Cannot load container %s because it was created with another graph driver.", container.ID)
		}
	}

	var migrateLegacyLinks bool
	restartContainers := make(map[*container.Container]chan struct{})
	for _, c := range containers {
		if err := daemon.registerName(c); err != nil {
			logrus.Errorf("Failed to register container %s: %s", c.ID, err)
			continue
		}
		if err := daemon.Register(c); err != nil {
			logrus.Errorf("Failed to register container %s: %s", c.ID, err)
			continue
		}
	}
	var wg sync.WaitGroup
	var mapLock sync.Mutex
	for _, c := range containers {
		wg.Add(1)
		go func(c *container.Container) {
			defer wg.Done()
			rm := c.RestartManager(false)
			if c.IsRunning() || c.IsPaused() {
				// Fix activityCount such that graph mounts can be unmounted later
				if err := daemon.layerStore.ReinitRWLayer(c.RWLayer); err != nil {
					logrus.Errorf("Failed to ReinitRWLayer for %s due to %s", c.ID, err)
					return
				}
				if err := daemon.containerd.Restore(c.ID, libcontainerd.WithRestartManager(rm)); err != nil {
					logrus.Errorf("Failed to restore with containerd: %q", err)
					return
				}
			}
			// fixme: only if not running
			// get list of containers we need to restart
			if daemon.configStore.AutoRestart && !c.IsRunning() && !c.IsPaused() && c.ShouldRestart() {
				mapLock.Lock()
				restartContainers[c] = make(chan struct{})
				mapLock.Unlock()
			}

			// if c.hostConfig.Links is nil (not just empty), then it is using the old sqlite links and needs to be migrated
			if c.HostConfig != nil && c.HostConfig.Links == nil {
				migrateLegacyLinks = true
			}
		}(c)
	}
	wg.Wait()

	// migrate any legacy links from sqlite
	linkdbFile := filepath.Join(daemon.root, "linkgraph.db")
	var legacyLinkDB *graphdb.Database
	if migrateLegacyLinks {
		legacyLinkDB, err = graphdb.NewSqliteConn(linkdbFile)
		if err != nil {
			return fmt.Errorf("error connecting to legacy link graph DB %s, container links may be lost: %v", linkdbFile, err)
		}
		defer legacyLinkDB.Close()
	}

	// Now that all the containers are registered, register the links
	for _, c := range containers {
		if migrateLegacyLinks {
			if err := daemon.migrateLegacySqliteLinks(legacyLinkDB, c); err != nil {
				return err
			}
		}
		if err := daemon.registerLinks(c, c.HostConfig); err != nil {
			logrus.Errorf("failed to register link for container %s: %v", c.ID, err)
		}
	}

	group := sync.WaitGroup{}
	for c, notifier := range restartContainers {
		group.Add(1)

		go func(c *container.Container, chNotify chan struct{}) {
			defer group.Done()

			logrus.Debugf("Starting container %s", c.ID)

			// ignore errors here as this is a best effort to wait for children to be
			//   running before we try to start the container
			children := daemon.children(c)
			timeout := time.After(5 * time.Second)
			for _, child := range children {
				if notifier, exists := restartContainers[child]; exists {
					select {
					case <-notifier:
					case <-timeout:
					}
				}
			}
			if err := daemon.containerStart(c); err != nil {
				logrus.Errorf("Failed to start container %s: %s", c.ID, err)
			}
			close(chNotify)
		}(c, notifier)

	}
	group.Wait()

	// any containers that were started above would already have had this done,
	// however we need to now prepare the mountpoints for the rest of the containers as well.
	// This shouldn't cause any issue running on the containers that already had this run.
	// This must be run after any containers with a restart policy so that containerized plugins
	// can have a chance to be running before we try to initialize them.
	for _, c := range containers {
		// if the container has restart policy, do not
		// prepare the mountpoints since it has been done on restarting.
		// This is to speed up the daemon start when a restart container
		// has a volume and the volume dirver is not available.
		if _, ok := restartContainers[c]; ok {
			continue
		}
		group.Add(1)
		go func(c *container.Container) {
			defer group.Done()
			if err := daemon.prepareMountPoints(c); err != nil {
				logrus.Error(err)
			}
		}(c)
	}

	group.Wait()

	if !debug {
		if logrus.GetLevel() == logrus.InfoLevel {
			fmt.Println()
		}
		logrus.Info("Loading containers: done.")
	}

	return nil
}