//.........这里部分代码省略.........

	d := &Daemon{configStore: config}
	// Ensure the daemon is properly shutdown if there is a failure during
	// initialization
	defer func() {
		if err != nil {
			if err := d.Shutdown(); err != nil {
				logrus.Error(err)
			}
		}
	}()

	// Set the default isolation mode (only applicable on Windows)
	if err := d.setDefaultIsolation(); err != nil {
		return nil, fmt.Errorf("error setting default isolation mode: %v", err)
	}

	logrus.Debugf("Using default logging driver %s", config.LogConfig.Type)

	if err := configureMaxThreads(config); err != nil {
		logrus.Warnf("Failed to configure golang's threads limit: %v", err)
	}

	installDefaultAppArmorProfile()
	daemonRepo := filepath.Join(config.Root, "containers")
	if err := idtools.MkdirAllAs(daemonRepo, 0700, rootUID, rootGID); err != nil && !os.IsExist(err) {
		return nil, err
	}

	driverName := os.Getenv("DOCKER_DRIVER")
	if driverName == "" {
		driverName = config.GraphDriver
	}
	d.layerStore, err = layer.NewStoreFromOptions(layer.StoreOptions{
		StorePath:                 config.Root,
		MetadataStorePathTemplate: filepath.Join(config.Root, "image", "%s", "layerdb"),
		GraphDriver:               driverName,
		GraphDriverOptions:        config.GraphOptions,
		UIDMaps:                   uidMaps,
		GIDMaps:                   gidMaps,
	})
	if err != nil {
		return nil, err
	}

	graphDriver := d.layerStore.DriverName()
	imageRoot := filepath.Join(config.Root, "image", graphDriver)

	// Configure and validate the kernels security support
	if err := configureKernelSecuritySupport(config, graphDriver); err != nil {
		return nil, err
	}

	logrus.Debugf("Max Concurrent Downloads: %d", *config.MaxConcurrentDownloads)
	d.downloadManager = xfer.NewLayerDownloadManager(d.layerStore, *config.MaxConcurrentDownloads)
	logrus.Debugf("Max Concurrent Uploads: %d", *config.MaxConcurrentUploads)
	d.uploadManager = xfer.NewLayerUploadManager(*config.MaxConcurrentUploads)

	ifs, err := image.NewFSStoreBackend(filepath.Join(imageRoot, "imagedb"))
	if err != nil {
		return nil, err
	}

	d.imageStore, err = image.NewImageStore(ifs, d.layerStore)
	if err != nil {
		return nil, err

// NewDaemon sets up everything for the daemon to be able to service
// requests from the webserver.
func NewDaemon(config *Config, registryService *registry.Service) (daemon *Daemon, err error) {
	setDefaultMtu(config)

	// Ensure we have compatible configuration options
	if err := checkConfigOptions(config); err != nil {
		return nil, err
	}

	// Do we have a disabled network?
	config.DisableBridge = isBridgeNetworkDisabled(config)

	// Verify the platform is supported as a daemon
	if !platformSupported {
		return nil, errSystemNotSupported
	}

	// Validate platform-specific requirements
	if err := checkSystem(); err != nil {
		return nil, err
	}

	// set up SIGUSR1 handler on Unix-like systems, or a Win32 global event
	// on Windows to dump Go routine stacks
	setupDumpStackTrap()

	uidMaps, gidMaps, err := setupRemappedRoot(config)
	if err != nil {
		return nil, err
	}
	rootUID, rootGID, err := idtools.GetRootUIDGID(uidMaps, gidMaps)
	if err != nil {
		return nil, err
	}

	// get the canonical path to the Docker root directory
	var realRoot string
	if _, err := os.Stat(config.Root); err != nil && os.IsNotExist(err) {
		realRoot = config.Root
	} else {
		realRoot, err = fileutils.ReadSymlinkedDirectory(config.Root)
		if err != nil {
			return nil, fmt.Errorf("Unable to get the full path to root (%s): %s", config.Root, err)
		}
	}

	if err = setupDaemonRoot(config, realRoot, rootUID, rootGID); err != nil {
		return nil, err
	}

	// set up the tmpDir to use a canonical path
	tmp, err := tempDir(config.Root, rootUID, rootGID)
	if err != nil {
		return nil, fmt.Errorf("Unable to get the TempDir under %s: %s", config.Root, err)
	}
	realTmp, err := fileutils.ReadSymlinkedDirectory(tmp)
	if err != nil {
		return nil, fmt.Errorf("Unable to get the full path to the TempDir (%s): %s", tmp, err)
	}
	os.Setenv("TMPDIR", realTmp)

	d := &Daemon{}
	// Ensure the daemon is properly shutdown if there is a failure during
	// initialization
	defer func() {
		if err != nil {
			if err := d.Shutdown(); err != nil {
				logrus.Error(err)
			}
		}
	}()

	// Verify logging driver type
	if config.LogConfig.Type != "none" {
		if _, err := logger.GetLogDriver(config.LogConfig.Type); err != nil {
			return nil, fmt.Errorf("error finding the logging driver: %v", err)
		}
	}
	logrus.Debugf("Using default logging driver %s", config.LogConfig.Type)

	daemonRepo := filepath.Join(config.Root, "containers")
	if err := idtools.MkdirAllAs(daemonRepo, 0700, rootUID, rootGID); err != nil && !os.IsExist(err) {
		return nil, err
	}

	driverName := os.Getenv("DOCKER_DRIVER")
	if driverName == "" {
		driverName = config.GraphDriver
	}
	d.layerStore, err = layer.NewStoreFromOptions(layer.StoreOptions{
		StorePath:                 config.Root,
		MetadataStorePathTemplate: filepath.Join(config.Root, "image", "%s", "layerdb"),
		GraphDriver:               driverName,
		GraphDriverOptions:        config.GraphOptions,
		UIDMaps:                   uidMaps,
		GIDMaps:                   gidMaps,
	})
	if err != nil {
		return nil, err
//.........这里部分代码省略.........