func (m customImageMap) Set(value string) error {
	parts := strings.Split(value, ",")
	if len(parts) != 2 {
		return errors.New("invalid custome image format, expected \"name,reference\"")
	}
	ref, err := reference.Parse(parts[0])
	if err != nil {
		return err
	}
	namedTagged, ok := ref.(reference.NamedTagged)
	if !ok {
		return fmt.Errorf("reference %s must contain name and tag", ref.String())
	}
	source, err := reference.ParseNamed(parts[1])
	if err != nil {
		return err
	}

	m[parts[0]] = CustomImage{
		Source: source.String(),
		Target: namedTagged,
	}

	return nil
}

func (ttles *TTLExpirationScheduler) startTimer(entry *schedulerEntry, ttl time.Duration) *time.Timer {
	return time.AfterFunc(ttl, func() {
		ttles.Lock()
		defer ttles.Unlock()

		var f expiryFunc

		switch entry.EntryType {
		case entryTypeBlob:
			f = ttles.onBlobExpire
		case entryTypeManifest:
			f = ttles.onManifestExpire
		default:
			f = func(reference.Reference) error {
				return fmt.Errorf("scheduler entry type")
			}
		}

		ref, err := reference.Parse(entry.Key)
		if err == nil {
			if err := f(ref); err != nil {
				context.GetLogger(ttles.ctx).Errorf("Scheduler error returned from OnExpire(%s): %s", entry.Key, err)
			}
		} else {
			context.GetLogger(ttles.ctx).Errorf("Error unpacking reference: %s", err)
		}

		delete(ttles.entries, entry.Key)
		ttles.indexDirty = true
	})
}

// matchImageIDOnly checks that the given image specifier is a digest-only
// reference, and that it matches the given image.
func matchImageIDOnly(inspected dockertypes.ImageInspect, image string) bool {
	// If the image ref is literally equal to the inspected image's ID,
	// just return true here (this might be the case for Docker 1.9,
	// where we won't have a digest for the ID)
	if inspected.ID == image {
		return true
	}

	// Otherwise, we should try actual parsing to be more correct
	ref, err := dockerref.Parse(image)
	if err != nil {
		glog.V(4).Infof("couldn't parse image reference %q: %v", image, err)
		return false
	}

	digest, isDigested := ref.(dockerref.Digested)
	if !isDigested {
		glog.V(4).Infof("the image reference %q was not a digest reference")
		return false
	}

	id, err := dockerdigest.ParseDigest(inspected.ID)
	if err != nil {
		glog.V(4).Infof("couldn't parse image ID reference %q: %v", id, err)
		return false
	}

	if digest.Digest().Algorithm().String() == id.Algorithm().String() && digest.Digest().Hex() == id.Hex() {
		return true
	}

	glog.V(4).Infof("The reference %s does not directly refer to the given image's ID (%q)", image, inspected.ID)
	return false
}

func ensureImage(cli DockerClient, image string) (string, error) {
	ctx := context.Background()
	info, _, err := cli.ImageInspectWithRaw(ctx, image, false)
	if err == nil {
		logrus.Debugf("Image found locally %s", image)
		return info.ID, nil
	}

	if !client.IsErrImageNotFound(err) {
		logrus.Errorf("Error inspecting image %q: %v", image, err)
		return "", err
	}

	// Image must be tagged reference if it does not exist
	ref, err := reference.Parse(image)
	if err != nil {
		logrus.Errorf("Image is not valid reference %q: %v", image, err)
		return "", err
	}
	tagged, ok := ref.(reference.NamedTagged)
	if !ok {
		logrus.Errorf("Tagged reference required %q", image)
		return "", errors.New("invalid reference, tag needed")
	}

	pullStart := time.Now()
	pullOptions := types.ImagePullOptions{
		PrivilegeFunc: registryAuthNotSupported,
	}
	resp, err := cli.ImagePull(ctx, tagged.String(), pullOptions)
	if err != nil {
		logrus.Errorf("Error pulling image %q: %v", tagged.String(), err)
		return "", err
	}
	defer resp.Close()

	outFd, isTerminalOut := term.GetFdInfo(os.Stdout)

	if err = jsonmessage.DisplayJSONMessagesStream(resp, os.Stdout, outFd, isTerminalOut, nil); err != nil {
		logrus.Errorf("Error copying pull output: %v", err)
		return "", err
	}
	// TODO: Get pulled digest

	logFields := logrus.Fields{
		timerKey: time.Since(pullStart),
		"image":  tagged.String(),
	}
	logrus.WithFields(logFields).Info("image pulled")

	info, _, err = cli.ImageInspectWithRaw(ctx, tagged.String(), false)
	if err != nil {
		return "", nil
	}

	return info.ID, nil
}

func testRefs(t *testing.T) (reference.Reference, reference.Reference, reference.Reference) {
	ref1, err := reference.Parse("[email protected]:aaaaeaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
	if err != nil {
		t.Fatalf("could not parse reference: %v", err)
	}

	ref2, err := reference.Parse("[email protected]:bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb")
	if err != nil {
		t.Fatalf("could not parse reference: %v", err)
	}

	ref3, err := reference.Parse("[email protected]:cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc")
	if err != nil {
		t.Fatalf("could not parse reference: %v", err)
	}

	return ref1, ref2, ref3
}

// parseImageName parses a docker image string into two parts: repo and tag.
// If tag is empty, return the defaultImageTag.
func ParseImageName(image string) (string, string) {
	ref, _ := reference.Parse(image)
	switch ref := ref.(type) {
	default:
		return ref.String(), defaultImageTag
	case reference.NamedTagged:
		return ref.Name(), ref.Tag()
	case reference.Named:
		return ref.Name(), defaultImageTag
	}
}

func getNamedTagged(image string) (reference.NamedTagged, error) {
	ref, err := reference.Parse(image)
	if err != nil {
		return nil, err
	}
	named, ok := ref.(reference.NamedTagged)
	if !ok {
		return nil, fmt.Errorf("Image reference must have name and tag: %s", image)
	}
	return named, nil
}

func assertTagged(image string) reference.NamedTagged {
	ref, err := reference.Parse(image)
	if err != nil {
		logrus.Panicf("Invalid reference %q: %v", image, err)
	}
	named, ok := ref.(reference.NamedTagged)
	if !ok {
		logrus.Panicf("Image reference must have name and tag: %s", image)
	}

	return named
}

func newSuiteConfiguration(path string, config suiteConfiguration) (*configurationSuite, error) {
	customImages := make([]CustomImage, 0, len(config.CustomImages))
	for _, value := range config.CustomImages {
		ref, err := reference.Parse(value.Tag)
		if err != nil {
			return nil, err
		}
		target, ok := ref.(reference.NamedTagged)
		if !ok {
			return nil, fmt.Errorf("expecting name:tag for image target, got %s", value.Tag)
		}

		customImages = append(customImages, CustomImage{
			Source: value.Default,
			Target: target,
		})
	}
	images := make([]reference.NamedTagged, 0, len(config.Images))
	for _, image := range config.Images {
		named, err := getNamedTagged(image)
		if err != nil {
			return nil, err
		}
		images = append(images, named)
	}

	var base reference.NamedTagged
	if config.Base != "" {
		var err error
		base, err = getNamedTagged(config.Base)
		if err != nil {
			return nil, err
		}
	}

	name := config.Name
	if name == "" {
		name = filepath.Base(path)
	}

	return &configurationSuite{
		config:       config,
		path:         path,
		base:         base,
		customImages: customImages,
		images:       images,

		resolvedName: name,
	}, nil
}

func populateTestStorage(
	t *testing.T,
	driver driver.StorageDriver,
	setManagedByOpenShift bool,
	schemaVersion int,
	repoImages map[string]int,
	testImages map[string][]*imageapi.Image,
) (map[string][]*imageapi.Image, error) {
	ctx := context.Background()
	reg, err := storage.NewRegistry(ctx, driver)
	if err != nil {
		t.Fatalf("error creating registry: %v", err)
	}

	result := make(map[string][]*imageapi.Image)
	for key, value := range testImages {
		images := make([]*imageapi.Image, len(value))
		copy(images, value)
		result[key] = images
	}

	for imageReference := range repoImages {
		parsed, err := reference.Parse(imageReference)
		if err != nil {
			t.Fatalf("failed to parse reference %q: %v", imageReference, err)
		}
		namedTagged, ok := parsed.(reference.NamedTagged)
		if !ok {
			t.Fatalf("expected NamedTagged reference, not %T", parsed)
		}

		imageCount := repoImages[imageReference]

		for i := 0; i < imageCount; i++ {
			img, err := storeTestImage(ctx, reg, namedTagged, schemaVersion, setManagedByOpenShift)
			if err != nil {
				t.Fatal(err)
			}
			arr := result[imageReference]
			t.Logf("created image %[email protected]%s image with layers:", namedTagged.Name(), img.Name)
			for _, l := range img.DockerImageLayers {
				t.Logf("  %s of size %d", l.Name, l.LayerSize)
			}
			result[imageReference] = append(arr, img)
		}
	}

	return result, nil
}

func mustImage(source, target, version string) CustomImage {
	ref, err := reference.Parse(target)
	if err != nil {
		panic(err)
	}
	namedTagged, ok := ref.(reference.NamedTagged)
	if !ok {
		panic("must provided named tagged for image target")
	}

	return CustomImage{
		Source:  source,
		Target:  namedTagged,
		Version: version,
	}
}

func tagImage(ctx context.Context, cli DockerClient, img, tag string) error {
	ref, err := reference.Parse(tag)
	if err != nil {
		return fmt.Errorf("invalid tag %s: %v", tag, err)
	}
	namedTagged, ok := ref.(reference.NamedTagged)
	if !ok {
		return fmt.Errorf("expecting named tagged reference: %s", tag)
	}
	tagOptions := types.ImageTagOptions{
		Force: true,
	}
	if err := cli.ImageTag(ctx, img, namedTagged.String(), tagOptions); err != nil {
		return fmt.Errorf("error tagging image %s as %s: %v", img, tag, err)
	}

	return nil
}

func tagImage(client *dockerclient.Client, img, tag string) error {
	ref, err := reference.Parse(tag)
	if err != nil {
		return fmt.Errorf("invalid tag %s: %v", tag, err)
	}
	namedTagged, ok := ref.(reference.NamedTagged)
	if !ok {
		return fmt.Errorf("expecting named tagged reference: %s", tag)
	}
	tagOptions := dockerclient.TagImageOptions{
		Repo:  namedTagged.Name(),
		Tag:   namedTagged.Tag(),
		Force: true,
	}
	if err := client.TagImage(img, tagOptions); err != nil {
		return fmt.Errorf("error tagging image %s as %s: %v", img, tag, err)
	}

	return nil
}

func ensureImage(client DockerClient, image string) (string, error) {
	info, err := client.InspectImage(image)
	if err == nil {
		logrus.Debugf("Image found locally %s", image)
		return info.ID, nil
	}
	if err != dockerclient.ErrNoSuchImage {
		logrus.Errorf("Error inspecting image %q: %v", image, err)
		return "", err
	}

	// Image must be tagged reference if it does not exist
	ref, err := reference.Parse(image)
	if err != nil {
		logrus.Debugf("Image is not valid reference %q: %v", image, err)
	}
	tagged, ok := ref.(reference.NamedTagged)
	if !ok {
		logrus.Debugf("Tagged reference required %q", image)
		return "", errors.New("invalid reference, tag needed")
	}

	logrus.Infof("Pulling image %s", tagged.String())

	pullOptions := dockerclient.PullImageOptions{
		Repository:   tagged.Name(),
		Tag:          tagged.Tag(),
		OutputStream: os.Stdout,
	}
	if err := client.PullImage(pullOptions, dockerclient.AuthConfiguration{}); err != nil {
		logrus.Errorf("Error pulling image %q: %v", tagged.String(), err)
		return "", err
	}
	// TODO: Get pulled digest and inspect by digest
	info, err = client.InspectImage(tagged.String())
	if err != nil {
		return "", nil
	}

	return info.ID, nil
}

func (m customImageMap) Set(value string) error {
	parts := strings.Split(value, ",")
	if len(parts) < 2 || len(parts) > 3 {
		return errors.New("invalid custom image format, expected \"name,reference[,version]\"")
	}
	ref, err := reference.Parse(parts[0])
	if err != nil {
		return err
	}
	namedTagged, ok := ref.(reference.NamedTagged)
	if !ok {
		return fmt.Errorf("reference %s must contain name and tag", ref.String())
	}
	source, err := reference.ParseNamed(parts[1])
	if err != nil {
		return err
	}

	var version string
	if len(parts) == 3 {
		version = parts[2]
	} else if refTag, ok := source.(reference.Tagged); ok {
		version = refTag.Tag()
	} else {
		// TODO: In this case is it better to leave it blank and use the default
		// from the configuration file?
		version = namedTagged.Tag()
	}

	key := fmt.Sprintf("%s,%s", parts[0], parts[1])
	m[key] = CustomImage{
		Source:  source.String(),
		Target:  namedTagged,
		Version: version,
	}

	return nil
}

// TestValidateManifest verifies the validateManifest function
func TestValidateManifest(t *testing.T) {
	expectedDigest, err := reference.Parse("[email protected]:02fee8c3220ba806531f606525eceb83f4feb654f62b207191b1c9209188dedd")
	if err != nil {
		t.Fatal("could not parse reference")
	}
	expectedFSLayer0 := digest.Digest("sha256:a3ed95caeb02ffe68cdd9fd84406680ae93d633cb16422d00e8a7c22955b46d4")

	// Good manifest

	goodManifestBytes, err := ioutil.ReadFile("fixtures/validate_manifest/good_manifest")
	if err != nil {
		t.Fatal("error reading fixture:", err)
	}

	var goodSignedManifest schema1.SignedManifest
	err = json.Unmarshal(goodManifestBytes, &goodSignedManifest)
	if err != nil {
		t.Fatal("error unmarshaling manifest:", err)
	}

	verifiedManifest, err := verifyManifest(&goodSignedManifest, expectedDigest)
	if err != nil {
		t.Fatal("validateManifest failed:", err)
	}

	if verifiedManifest.FSLayers[0].BlobSum != expectedFSLayer0 {
		t.Fatal("unexpected FSLayer in good manifest")
	}

	// "Extra data" manifest

	extraDataManifestBytes, err := ioutil.ReadFile("fixtures/validate_manifest/extra_data_manifest")
	if err != nil {
		t.Fatal("error reading fixture:", err)
	}

	var extraDataSignedManifest schema1.SignedManifest
	err = json.Unmarshal(extraDataManifestBytes, &extraDataSignedManifest)
	if err != nil {
		t.Fatal("error unmarshaling manifest:", err)
	}

	verifiedManifest, err = verifyManifest(&extraDataSignedManifest, expectedDigest)
	if err != nil {
		t.Fatal("validateManifest failed:", err)
	}

	if verifiedManifest.FSLayers[0].BlobSum != expectedFSLayer0 {
		t.Fatal("unexpected FSLayer in extra data manifest")
	}

	// Bad manifest

	badManifestBytes, err := ioutil.ReadFile("fixtures/validate_manifest/bad_manifest")
	if err != nil {
		t.Fatal("error reading fixture:", err)
	}

	var badSignedManifest schema1.SignedManifest
	err = json.Unmarshal(badManifestBytes, &badSignedManifest)
	if err != nil {
		t.Fatal("error unmarshaling manifest:", err)
	}

	verifiedManifest, err = verifyManifest(&badSignedManifest, expectedDigest)
	if err == nil || !strings.HasPrefix(err.Error(), "image verification failed for digest") {
		t.Fatal("expected validateManifest to fail with digest error")
	}
}

//.........这里部分代码省略.........
			stat:   "nm/[email protected]" + etcdOnlyImages["nm/is"].DockerImageLayers[0].Name,
			images: []imageapi.Image{*testImages["nm/is:latest"][0]},
			imageStreams: []imageapi.ImageStream{
				{
					ObjectMeta: kapi.ObjectMeta{
						Namespace: "nm",
						Name:      "repo",
					},
					Status: imageapi.ImageStreamStatus{
						Tags: map[string]imageapi.TagEventList{
							"latest": {
								Items: []imageapi.TagEvent{
									{
										Image: testImages["nm/is:latest"][0].Name,
									},
								},
							},
						},
					},
				},
			},
			expectedError: distribution.ErrBlobUnknown,
		},

		{
			name:          "auth not performed",
			stat:          "nm/[email protected]" + testImages["nm/is:latest"][0].DockerImageLayers[0].Name,
			imageStreams:  []imageapi.ImageStream{{ObjectMeta: kapi.ObjectMeta{Namespace: "nm", Name: "is"}}},
			skipAuth:      true,
			expectedError: fmt.Errorf("openshift.auth.completed missing from context"),
		},

		{
			name:           "deferred error",
			stat:           "nm/[email protected]" + testImages["nm/is:latest"][0].DockerImageLayers[0].Name,
			imageStreams:   []imageapi.ImageStream{{ObjectMeta: kapi.ObjectMeta{Namespace: "nm", Name: "is"}}},
			deferredErrors: deferredErrors{"nm/is": ErrOpenShiftAccessDenied},
			expectedError:  ErrOpenShiftAccessDenied,
		},
	} {
		ref, err := reference.Parse(tc.stat)
		if err != nil {
			t.Errorf("[%s] failed to parse blob reference %q: %v", tc.name, tc.stat, err)
			continue
		}
		canonical, ok := ref.(reference.Canonical)
		if !ok {
			t.Errorf("[%s] not a canonical reference %q", tc.name, ref.String())
			continue
		}

		cachedLayers, err = newDigestToRepositoryCache(defaultDigestToRepositoryCacheSize)
		if err != nil {
			t.Fatal(err)
		}

		ctx := context.Background()
		if !tc.skipAuth {
			ctx = WithAuthPerformed(ctx)
		}
		if tc.deferredErrors != nil {
			ctx = WithDeferredErrors(ctx, tc.deferredErrors)
		}

		client := &testclient.Fake{}
		client.AddReactor("get", "imagestreams", imagetest.GetFakeImageStreamGetHandler(t, tc.imageStreams...))
		client.AddReactor("get", "images", registrytest.GetFakeImageGetHandler(t, tc.images...))

		reg, err := newTestRegistry(ctx, client, driver, defaultBlobRepositoryCacheTTL, tc.pullthrough, true)
		if err != nil {
			t.Errorf("[%s] unexpected error: %v", tc.name, err)
			continue
		}

		repo, err := reg.Repository(ctx, canonical)
		if err != nil {
			t.Errorf("[%s] unexpected error: %v", tc.name, err)
			continue
		}

		desc, err := repo.Blobs(ctx).Stat(ctx, canonical.Digest())
		if err != nil && tc.expectedError == nil {
			t.Errorf("[%s] got unexpected stat error: %v", tc.name, err)
			continue
		}
		if err == nil && tc.expectedError != nil {
			t.Errorf("[%s] got unexpected non-error", tc.name)
			continue
		}
		if !reflect.DeepEqual(err, tc.expectedError) {
			t.Errorf("[%s] got unexpected error: %s", tc.name, diff.ObjectGoPrintDiff(err, tc.expectedError))
			continue
		}
		if tc.expectedError == nil && !reflect.DeepEqual(desc, tc.expectedDescriptor) {
			t.Errorf("[%s] got unexpected descriptor: %s", tc.name, diff.ObjectGoPrintDiff(desc, tc.expectedDescriptor))
		}

		compareActions(t, tc.name, client.Actions(), tc.expectedActions)
	}
}

// Images returns a filtered list of images. filterArgs is a JSON-encoded set
// of filter arguments which will be interpreted by pkg/parsers/filters.
// filter is a shell glob string applied to repository names. The argument
// named all controls whether all images in the graph are filtered, or just
// the heads.
func (daemon *Daemon) Images(filterArgs, filter string, all bool) ([]*types.Image, error) {
	var (
		allImages    map[image.ID]*image.Image
		err          error
		danglingOnly = false
	)

	imageFilters, err := filters.FromParam(filterArgs)
	if err != nil {
		return nil, err
	}
	for name := range imageFilters {
		if _, ok := acceptedImageFilterTags[name]; !ok {
			return nil, fmt.Errorf("Invalid filter '%s'", name)
		}
	}

	if i, ok := imageFilters["dangling"]; ok {
		for _, value := range i {
			if v := strings.ToLower(value); v == "true" {
				danglingOnly = true
			} else if v != "false" {
				return nil, fmt.Errorf("Invalid filter 'dangling=%s'", v)
			}
		}
	}

	if danglingOnly {
		allImages = daemon.imageStore.Heads()
	} else {
		allImages = daemon.imageStore.Map()
	}

	images := []*types.Image{}

	var filterTagged bool
	if filter != "" {
		filterRef, err := reference.Parse(filter)
		if err == nil { // parse error means wildcard repo
			if _, ok := filterRef.(reference.Tagged); ok {
				filterTagged = true
			}
		}
	}

	for id, img := range allImages {
		if _, ok := imageFilters["label"]; ok {
			if img.Config == nil {
				// Very old image that do not have image.Config (or even labels)
				continue
			}
			// We are now sure image.Config is not nil
			if !imageFilters.MatchKVList("label", img.Config.Labels) {
				continue
			}
		}

		layerID := img.RootFS.ChainID()
		var size int64
		if layerID != "" {
			l, err := daemon.layerStore.Get(layerID)
			if err != nil {
				return nil, err
			}

			size, err = l.Size()
			layer.ReleaseAndLog(daemon.layerStore, l)
			if err != nil {
				return nil, err
			}
		}

		newImage := newImage(img, size)

		for _, ref := range daemon.tagStore.References(id) {
			if filter != "" { // filter by tag/repo name
				if filterTagged { // filter by tag, require full ref match
					if ref.String() != filter {
						continue
					}
				} else if matched, err := path.Match(filter, ref.Name()); !matched || err != nil { // name only match, FIXME: docs say exact
					continue
				}
			}
			if _, ok := ref.(reference.Digested); ok {
				newImage.RepoDigests = append(newImage.RepoDigests, ref.String())
			}
			if _, ok := ref.(reference.Tagged); ok {
				newImage.RepoTags = append(newImage.RepoTags, ref.String())
			}
		}
		if newImage.RepoDigests == nil && newImage.RepoTags == nil {
			if all || len(daemon.imageStore.Children(id)) == 0 {
				if filter != "" { // skip images with no references if filtering by tag
					continue
//.........这里部分代码省略.........

// NewBuilder creates a new builder.
func NewBuilder(daemonURL string, tlsConfig *tls.Config, contextDirectory, dockerfilePath, repoTag string) (*Builder, error) {
	// Validate that the context directory exists.
	stat, err := os.Stat(contextDirectory)
	if err != nil {
		return nil, fmt.Errorf("unable to access build context directory: %s", err)
	}
	if !stat.IsDir() {
		return nil, fmt.Errorf("context must be a directory")
	}

	if dockerfilePath == "" {
		// Use Default path.
		dockerfilePath = filepath.Join(contextDirectory, "Dockerfile")
	}

	if _, err := os.Stat(dockerfilePath); err != nil {
		return nil, fmt.Errorf("unable to access build file: %s", err)
	}

	ref, err := reference.Parse(repoTag)
	if err != nil {
		if err != reference.ErrNameEmpty {
			return nil, fmt.Errorf("invalid tag: %s", err)
		}
	}

	client, err := dockerclient.NewDockerClient(daemonURL, tlsConfig)
	if err != nil {
		return nil, fmt.Errorf("unable to initialize client: %s", err)
	}

	b := &Builder{
		daemonURL:        daemonURL,
		tlsConfig:        tlsConfig,
		client:           client,
		contextDirectory: contextDirectory,
		dockerfilePath:   dockerfilePath,
		ref:              ref,
		out:              os.Stdout,
		config: &config{
			Labels:       map[string]string{},
			ExposedPorts: map[string]struct{}{},
			Volumes:      map[string]struct{}{},
		},
	}

	// Register Dockerfile Directive Handlers
	b.handlers = map[string]handlerFunc{
		commands.Cmd:        b.handleCmd,
		commands.Copy:       b.handleCopy,
		commands.Entrypoint: b.handleEntrypoint,
		commands.Env:        b.handleEnv,
		commands.Expose:     b.handleExpose,
		commands.Extract:    b.handleExtract,
		commands.From:       b.handleFrom,
		commands.Label:      b.handleLabel,
		commands.Maintainer: b.handleMaintainer,
		commands.Run:        b.handleRun,
		commands.User:       b.handleUser,
		commands.Volume:     b.handleVolume,
		commands.Workdir:    b.handleWorkdir,

		// Not implemented for now:
		commands.Add:     b.handleAdd,
		commands.Onbuild: b.handleOnbuild,
	}

	if err := b.loadCache(); err != nil {
		return nil, fmt.Errorf("unable to load build cache: %s", err)
	}

	return b, nil
}