func mkTestTagStore(root string, t *testing.T) *TagStore {
	driver, err := graphdriver.New(root)
	if err != nil {
		t.Fatal(err)
	}
	graph, err := NewGraph(root, driver)
	if err != nil {
		t.Fatal(err)
	}
	store, err := NewTagStore(path.Join(root, "tags"), graph)
	if err != nil {
		t.Fatal(err)
	}
	archive, err := fakeTar()
	if err != nil {
		t.Fatal(err)
	}
	img := &image.Image{ID: testImageID}
	// FIXME: this fails on Darwin with:
	// tags_unit_test.go:36: mkdir /var/folders/7g/b3ydb5gx4t94ndr_cljffbt80000gq/T/docker-test569b-tRunner-075013689/vfs/dir/foo/etc/postgres: permission denied
	if err := graph.Register(nil, archive, img); err != nil {
		t.Fatal(err)
	}
	if err := store.Set(testImageName, "", testImageID, false); err != nil {
		t.Fatal(err)
	}
	return store
}

func tempGraph(t *testing.T) (*graph.Graph, graphdriver.Driver) {
	tmp, err := ioutil.TempDir("", "docker-graph-")
	if err != nil {
		t.Fatal(err)
	}
	driver, err := graphdriver.New(tmp, nil)
	if err != nil {
		t.Fatal(err)
	}
	graph, err := graph.NewGraph(tmp, driver)
	if err != nil {
		t.Fatal(err)
	}
	return graph, driver
}

func NewDaemonFromDirectory(config *daemonconfig.Config, eng *engine.Engine) (*Daemon, error) {
	if !config.EnableSelinuxSupport {
		selinux.SetDisabled()
	}

	// Create the root directory if it doesn't exists
	if err := os.MkdirAll(config.Root, 0700); err != nil && !os.IsExist(err) {
		return nil, err
	}

	// Set the default driver
	graphdriver.DefaultDriver = config.GraphDriver

	// Load storage driver
	driver, err := graphdriver.New(config.Root)
	if err != nil {
		return nil, err
	}
	utils.Debugf("Using graph driver %s", driver)

	if err := remountPrivate(config.Root); err != nil {
		return nil, err
	}

	daemonRepo := path.Join(config.Root, "containers")

	if err := os.MkdirAll(daemonRepo, 0700); err != nil && !os.IsExist(err) {
		return nil, err
	}

	// Migrate the container if it is aufs and aufs is enabled
	if err = migrateIfAufs(driver, config.Root); err != nil {
		return nil, err
	}

	utils.Debugf("Creating images graph")
	g, err := graph.NewGraph(path.Join(config.Root, "graph"), driver)
	if err != nil {
		return nil, err
	}

	// We don't want to use a complex driver like aufs or devmapper
	// for volumes, just a plain filesystem
	volumesDriver, err := graphdriver.GetDriver("vfs", config.Root)
	if err != nil {
		return nil, err
	}
	utils.Debugf("Creating volumes graph")
	volumes, err := graph.NewGraph(path.Join(config.Root, "volumes"), volumesDriver)
	if err != nil {
		return nil, err
	}
	utils.Debugf("Creating repository list")
	repositories, err := graph.NewTagStore(path.Join(config.Root, "repositories-"+driver.String()), g)
	if err != nil {
		return nil, fmt.Errorf("Couldn't create Tag store: %s", err)
	}

	if !config.DisableNetwork {
		job := eng.Job("init_networkdriver")

		job.SetenvBool("EnableIptables", config.EnableIptables)
		job.SetenvBool("InterContainerCommunication", config.InterContainerCommunication)
		job.SetenvBool("EnableIpForward", config.EnableIpForward)
		job.Setenv("BridgeIface", config.BridgeIface)
		job.Setenv("BridgeIP", config.BridgeIP)
		job.Setenv("DefaultBindingIP", config.DefaultIp.String())

		if err := job.Run(); err != nil {
			return nil, err
		}
	}

	graphdbPath := path.Join(config.Root, "linkgraph.db")
	graph, err := graphdb.NewSqliteConn(graphdbPath)
	if err != nil {
		return nil, err
	}

	localCopy := path.Join(config.Root, "init", fmt.Sprintf("dockerinit-%s", dockerversion.VERSION))
	sysInitPath := utils.DockerInitPath(localCopy)
	if sysInitPath == "" {
		return nil, fmt.Errorf("Could not locate dockerinit: This usually means docker was built incorrectly. See http://docs.docker.io/en/latest/contributing/devenvironment for official build instructions.")
	}

	if sysInitPath != localCopy {
		// When we find a suitable dockerinit binary (even if it's our local binary), we copy it into config.Root at localCopy for future use (so that the original can go away without that being a problem, for example during a package upgrade).
		if err := os.Mkdir(path.Dir(localCopy), 0700); err != nil && !os.IsExist(err) {
			return nil, err
		}
		if _, err := utils.CopyFile(sysInitPath, localCopy); err != nil {
			return nil, err
		}
		if err := os.Chmod(localCopy, 0700); err != nil {
			return nil, err
		}
		sysInitPath = localCopy
	}

	sysInfo := sysinfo.New(false)
//.........这里部分代码省略.........

func main() {
	flag.Parse()

	maxProcs := runtime.NumCPU()
	prevMaxProcs := runtime.GOMAXPROCS(maxProcs)

	log.Println("set GOMAXPROCS to", maxProcs, "was", prevMaxProcs)

	if *binPath == "" {
		log.Fatalln("must specify -bin with linux backend")
	}

	if *depotPath == "" {
		log.Fatalln("must specify -depot with linux backend")
	}

	if *rootFSPath == "" {
		log.Fatalln("must specify -rootfs with linux backend")
	}

	uidPool := uid_pool.New(uint32(*uidPoolStart), uint32(*uidPoolSize))

	_, ipNet, err := net.ParseCIDR(*networkPool)
	if err != nil {
		log.Fatalln("error parsing CIDR:", err)
	}

	networkPool := network_pool.New(ipNet)

	// TODO: use /proc/sys/net/ipv4/ip_local_port_range by default (end + 1)
	portPool := port_pool.New(uint32(*portPoolStart), uint32(*portPoolSize))

	runner := linux_command_runner.New(*debug)

	quotaManager, err := quota_manager.New(*depotPath, *binPath, runner)
	if err != nil {
		log.Fatalln("error creating quota manager:", err)
	}

	if *disableQuotas {
		quotaManager.Disable()
	}

	graphDriver, err := graphdriver.New(*graphRoot)
	if err != nil {
		log.Fatalln("error constructing graph driver:", err)
	}

	graph, err := graph.NewGraph(*graphRoot, graphDriver)
	if err != nil {
		log.Fatalln("error constructing graph:", err)
	}

	reg, err := registry.NewRegistry(nil, nil, *dockerRegistry)
	if err != nil {
		log.Fatalln(err)
	}

	pool := container_pool.New(
		*binPath,
		*depotPath,
		*rootFSPath,
		repository_fetcher.Retryable{repository_fetcher.New(reg, graph)},
		graphDriver,
		uidPool,
		networkPool,
		portPool,
		strings.Split(*denyNetworks, ","),
		strings.Split(*allowNetworks, ","),
		runner,
		quotaManager,
	)

	systemInfo := system_info.NewProvider(*depotPath)

	backend := linux_backend.New(pool, systemInfo, *snapshotsPath)

	log.Println("setting up backend")

	err = backend.Setup()
	if err != nil {
		log.Fatalln("failed to set up backend:", err)
	}

	log.Println("starting server; listening with", *listenNetwork, "on", *listenAddr)

	graceTime := *containerGraceTime

	wardenServer := server.New(*listenNetwork, *listenAddr, graceTime, backend)

	err = wardenServer.Start()
	if err != nil {
		log.Fatalln("failed to start:", err)
	}

	signals := make(chan os.Signal, 1)

	go func() {
		<-signals
		log.Println("stopping...")
//.........这里部分代码省略.........