Add migratev1 package

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

migrate/v1/migratev1.go

@@ -0,0 +1,364 @@
+package v1
+
+import (
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	"encoding/json"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/docker/distribution/digest"
+	"github.com/docker/distribution/reference"
+	"github.com/docker/docker/distribution/metadata"
+	"github.com/docker/docker/image"
+	imagev1 "github.com/docker/docker/image/v1"
+	"github.com/docker/docker/layer"
+	"github.com/docker/docker/tag"
+)
+
+type graphIDRegistrar interface {
+	RegisterByGraphID(string, layer.ChainID, string) (layer.Layer, error)
+	Release(layer.Layer) ([]layer.Metadata, error)
+}
+
+type graphIDMounter interface {
+	MountByGraphID(string, string, layer.ChainID) (layer.RWLayer, error)
+	Unmount(string) error
+}
+
+const (
+	graphDirName                 = "graph"
+	tarDataFileName              = "tar-data.json.gz"
+	migrationFileName            = ".migration-v1-images.json"
+	migrationTagsFileName        = ".migration-v1-tags"
+	containersDirName            = "containers"
+	configFileNameLegacy         = "config.json"
+	configFileName               = "config.v2.json"
+	repositoriesFilePrefixLegacy = "repositories-"
+)
+
+var (
+	errUnsupported = errors.New("migration is not supported")
+)
+
+// Migrate takes an old graph directory and transforms the metadata into the
+// new format.
+func Migrate(root, driverName string, ls layer.Store, is image.Store, ts tag.Store, ms metadata.Store) error {
+	mappings := make(map[string]image.ID)
+
+	if registrar, ok := ls.(graphIDRegistrar); !ok {
+		return errUnsupported
+	} else if err := migrateImages(root, registrar, is, ms, mappings); err != nil {
+		return err
+	}
+
+	if mounter, ok := ls.(graphIDMounter); !ok {
+		return errUnsupported
+	} else if err := migrateContainers(root, mounter, is, mappings); err != nil {
+		return err
+	}
+
+	if err := migrateTags(root, driverName, ts, mappings); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func migrateImages(root string, ls graphIDRegistrar, is image.Store, ms metadata.Store, mappings map[string]image.ID) error {
+	graphDir := filepath.Join(root, graphDirName)
+	if _, err := os.Lstat(graphDir); err != nil {
+		if os.IsNotExist(err) {
+			return nil
+		}
+		return err
+	}
+
+	mfile := filepath.Join(root, migrationFileName)
+	f, err := os.Open(mfile)
+	if err != nil && !os.IsNotExist(err) {
+		return err
+	} else if err == nil {
+		err := json.NewDecoder(f).Decode(&mappings)
+		if err != nil {
+			f.Close()
+			return err
+		}
+		f.Close()
+	}
+
+	dir, err := ioutil.ReadDir(graphDir)
+	if err != nil {
+		return err
+	}
+	for _, v := range dir {
+		v1ID := v.Name()
+		if err := imagev1.ValidateID(v1ID); err != nil {
+			continue
+		}
+		if _, exists := mappings[v1ID]; exists {
+			continue
+		}
+		if err := migrateImage(v1ID, root, ls, is, ms, mappings); err != nil {
+			continue
+		}
+	}
+
+	f, err = os.OpenFile(mfile, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	if err := json.NewEncoder(f).Encode(mappings); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func migrateContainers(root string, ls graphIDMounter, is image.Store, imageMappings map[string]image.ID) error {
+	containersDir := filepath.Join(root, containersDirName)
+	dir, err := ioutil.ReadDir(containersDir)
+	if err != nil {
+		return err
+	}
+	for _, v := range dir {
+		id := v.Name()
+
+		if _, err := os.Stat(filepath.Join(containersDir, id, configFileName)); err == nil {
+			continue
+		}
+
+		containerJSON, err := ioutil.ReadFile(filepath.Join(containersDir, id, configFileNameLegacy))
+		if err != nil {
+			return err
+		}
+
+		var c map[string]*json.RawMessage
+		if err := json.Unmarshal(containerJSON, &c); err != nil {
+			return err
+		}
+
+		imageStrJSON, ok := c["Image"]
+		if !ok {
+			return fmt.Errorf("invalid container configuration for %v", id)
+		}
+
+		var image string
+		if err := json.Unmarshal([]byte(*imageStrJSON), &image); err != nil {
+			return err
+		}
+		imageID, ok := imageMappings[image]
+		if !ok {
+			logrus.Errorf("image not migrated %v", imageID) // non-fatal error
+			continue
+		}
+
+		c["Image"] = rawJSON(imageID)
+
+		containerJSON, err = json.Marshal(c)
+		if err != nil {
+			return err
+		}
+
+		if err := ioutil.WriteFile(filepath.Join(containersDir, id, configFileName), containerJSON, 0600); err != nil {
+			return err
+		}
+
+		img, err := is.Get(imageID)
+		if err != nil {
+			return err
+		}
+
+		_, err = ls.MountByGraphID(id, id, img.RootFS.ChainID())
+		if err != nil {
+			return err
+		}
+
+		err = ls.Unmount(id)
+		if err != nil {
+			return err
+		}
+
+		logrus.Infof("migrated container %s to point to %s", id, imageID)
+
+	}
+	return nil
+}
+
+type tagAdder interface {
+	Add(ref reference.Named, id image.ID, force bool) error
+}
+
+func migrateTags(root, driverName string, ts tagAdder, mappings map[string]image.ID) error {
+	migrationFile := filepath.Join(root, migrationTagsFileName)
+	if _, err := os.Lstat(migrationFile); !os.IsNotExist(err) {
+		return err
+	}
+
+	type repositories struct {
+		Repositories map[string]map[string]string
+	}
+
+	var repos repositories
+
+	f, err := os.Open(filepath.Join(root, repositoriesFilePrefixLegacy+driverName))
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil
+		}
+		return err
+	}
+	defer f.Close()
+	if err := json.NewDecoder(f).Decode(&repos); err != nil {
+		return err
+	}
+
+	for name, repo := range repos.Repositories {
+		for tag, id := range repo {
+			if strongID, exists := mappings[id]; exists {
+				ref, err := reference.WithName(name)
+				if err != nil {
+					logrus.Errorf("migrate tags: invalid name %q, %q", name, err)
+					continue
+				}
+				if dgst, err := digest.ParseDigest(tag); err == nil {
+					ref, err = reference.WithDigest(ref, dgst)
+					if err != nil {
+						logrus.Errorf("migrate tags: invalid digest %q, %q", dgst, err)
+						continue
+					}
+				} else {
+					ref, err = reference.WithTag(ref, tag)
+					if err != nil {
+						logrus.Errorf("migrate tags: invalid tag %q, %q", tag, err)
+						continue
+					}
+				}
+				if err := ts.Add(ref, strongID, false); err != nil {
+					logrus.Errorf("can't migrate tag %q for %q, err: %q", ref.String(), strongID, err)
+				}
+				logrus.Infof("migrated tag %s:%s to point to %s", name, tag, strongID)
+			}
+		}
+	}
+
+	mf, err := os.Create(migrationFile)
+	if err != nil {
+		return err
+	}
+	mf.Close()
+
+	return nil
+}
+
+func migrateImage(id, root string, ls graphIDRegistrar, is image.Store, ms metadata.Store, mappings map[string]image.ID) (err error) {
+	defer func() {
+		if err != nil {
+			logrus.Errorf("migration failed for %v, err: %v", id, err)
+		}
+	}()
+
+	jsonFile := filepath.Join(root, graphDirName, id, "json")
+	imageJSON, err := ioutil.ReadFile(jsonFile)
+	if err != nil {
+		return err
+	}
+	var parent struct {
+		Parent   string
+		ParentID digest.Digest `json:"parent_id"`
+	}
+	if err := json.Unmarshal(imageJSON, &parent); err != nil {
+		return err
+	}
+	if parent.Parent == "" && parent.ParentID != "" { // v1.9
+		parent.Parent = parent.ParentID.Hex()
+	}
+	// compatibilityID for parent
+	parentCompatibilityID, err := ioutil.ReadFile(filepath.Join(root, graphDirName, id, "parent"))
+	if err == nil && len(parentCompatibilityID) > 0 {
+		parent.Parent = string(parentCompatibilityID)
+	}
+
+	var parentID image.ID
+	if parent.Parent != "" {
+		var exists bool
+		if parentID, exists = mappings[parent.Parent]; !exists {
+			if err := migrateImage(parent.Parent, root, ls, is, ms, mappings); err != nil {
+				// todo: fail or allow broken chains?
+				return err
+			}
+			parentID = mappings[parent.Parent]
+		}
+	}
+
+	rootFS := image.NewRootFS()
+	var history []image.History
+
+	if parentID != "" {
+		parentImg, err := is.Get(parentID)
+		if err != nil {
+			return err
+		}
+
+		rootFS = parentImg.RootFS
+		history = parentImg.History
+	}
+
+	layer, err := ls.RegisterByGraphID(id, rootFS.ChainID(), filepath.Join(filepath.Join(root, graphDirName, id, tarDataFileName)))
+	if err != nil {
+		return err
+	}
+	logrus.Infof("migrated layer %s to %s", id, layer.DiffID())
+
+	h, err := imagev1.HistoryFromConfig(imageJSON, false)
+	if err != nil {
+		return err
+	}
+	history = append(history, h)
+
+	rootFS.Append(layer.DiffID())
+
+	config, err := imagev1.MakeConfigFromV1Config(imageJSON, rootFS, history)
+	if err != nil {
+		return err
+	}
+	strongID, err := is.Create(config)
+	if err != nil {
+		return err
+	}
+	logrus.Infof("migrated image %s to %s", id, strongID)
+
+	if parentID != "" {
+		if err := is.SetParent(strongID, parentID); err != nil {
+			return err
+		}
+	}
+
+	checksum, err := ioutil.ReadFile(filepath.Join(root, graphDirName, id, "checksum"))
+	if err == nil { // best effort
+		dgst, err := digest.ParseDigest(string(checksum))
+		if err == nil {
+			blobSumService := metadata.NewBlobSumService(ms)
+			blobSumService.Add(layer.DiffID(), dgst)
+		}
+	}
+	_, err = ls.Release(layer)
+	if err != nil {
+		return err
+	}
+
+	mappings[id] = strongID
+	return
+}
+
+func rawJSON(value interface{}) *json.RawMessage {
+	jsonval, err := json.Marshal(value)
+	if err != nil {
+		return nil
+	}
+	return (*json.RawMessage)(&jsonval)
+}

migrate/v1/migratev1_test.go

@@ -0,0 +1,389 @@
+package v1
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"reflect"
+	"testing"
+
+	"github.com/docker/distribution/digest"
+	"github.com/docker/distribution/reference"
+	"github.com/docker/docker/distribution/metadata"
+	"github.com/docker/docker/image"
+	"github.com/docker/docker/layer"
+)
+
+func TestMigrateTags(t *testing.T) {
+	tmpdir, err := ioutil.TempDir("", "migrate-tags")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmpdir)
+
+	ioutil.WriteFile(filepath.Join(tmpdir, "repositories-generic"), []byte(`{"Repositories":{"busybox":{"latest":"b3ca410aa2c115c05969a7b2c8cf8a9fcf62c1340ed6a601c9ee50df337ec108","sha256:16a2a52884c2a9481ed267c2d46483eac7693b813a63132368ab098a71303f8a":"b3ca410aa2c115c05969a7b2c8cf8a9fcf62c1340ed6a601c9ee50df337ec108"},"registry":{"2":"5d165b8e4b203685301c815e95663231691d383fd5e3d3185d1ce3f8dddead3d","latest":"8d5547a9f329b1d3f93198cd661fb5117e5a96b721c5cf9a2c389e7dd4877128"}}}`), 0600)
+
+	ta := &mockTagAdder{}
+	err = migrateTags(tmpdir, "generic", ta, map[string]image.ID{
+		"5d165b8e4b203685301c815e95663231691d383fd5e3d3185d1ce3f8dddead3d": image.ID("sha256:2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae"),
+		"b3ca410aa2c115c05969a7b2c8cf8a9fcf62c1340ed6a601c9ee50df337ec108": image.ID("sha256:fcde2b2edba56bf408601fb721fe9b5c338d10ee429ea04fae5511b68fbf8fb9"),
+		"abcdef3434c115c05969a7b2c8cf8a9fcf62c1340ed6a601c9ee50df337ec108": image.ID("sha256:56434342345ae68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae"),
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	expected := map[string]string{
+		"busybox:latest": "sha256:fcde2b2edba56bf408601fb721fe9b5c338d10ee429ea04fae5511b68fbf8fb9",
+		"busybox@sha256:16a2a52884c2a9481ed267c2d46483eac7693b813a63132368ab098a71303f8a": "sha256:fcde2b2edba56bf408601fb721fe9b5c338d10ee429ea04fae5511b68fbf8fb9",
+		"registry:2": "sha256:2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae",
+	}
+
+	if !reflect.DeepEqual(expected, ta.refs) {
+		t.Fatalf("Invalid migrated tags: expected %q, got %q", expected, ta.refs)
+	}
+
+	// second migration is no-op
+	ioutil.WriteFile(filepath.Join(tmpdir, "repositories-generic"), []byte(`{"Repositories":{"busybox":{"latest":"b3ca410aa2c115c05969a7b2c8cf8a9fcf62c1340ed6a601c9ee50df337ec108"`), 0600)
+	err = migrateTags(tmpdir, "generic", ta, map[string]image.ID{
+		"b3ca410aa2c115c05969a7b2c8cf8a9fcf62c1340ed6a601c9ee50df337ec108": image.ID("sha256:fcde2b2edba56bf408601fb721fe9b5c338d10ee429ea04fae5511b68fbf8fb9"),
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !reflect.DeepEqual(expected, ta.refs) {
+		t.Fatalf("Invalid migrated tags: expected %q, got %q", expected, ta.refs)
+	}
+}
+
+func TestMigrateContainers(t *testing.T) {
+	tmpdir, err := ioutil.TempDir("", "migrate-containers")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmpdir)
+
+	err = addContainer(tmpdir, `{"State":{"Running":false,"Paused":false,"Restarting":false,"OOMKilled":false,"Dead":false,"Pid":0,"ExitCode":0,"Error":"","StartedAt":"2015-11-10T21:42:40.604267436Z","FinishedAt":"2015-11-10T21:42:41.869265487Z"},"ID":"f780ee3f80e66e9b432a57049597118a66aab8932be88e5628d4c824edbee37c","Created":"2015-11-10T21:42:40.433831551Z","Path":"sh","Args":[],"Config":{"Hostname":"f780ee3f80e6","Domainname":"","User":"","AttachStdin":true,"AttachStdout":true,"AttachStderr":true,"Tty":true,"OpenStdin":true,"StdinOnce":true,"Env":null,"Cmd":["sh"],"Image":"busybox","Volumes":null,"WorkingDir":"","Entrypoint":null,"OnBuild":null,"Labels":{}},"Image":"2c5ac3f849df8627fcf2822727f87c57f38b7129d3604fbc11d861fe856ff093","NetworkSettings":{"Bridge":"","EndpointID":"","Gateway":"","GlobalIPv6Address":"","GlobalIPv6PrefixLen":0,"HairpinMode":false,"IPAddress":"","IPPrefixLen":0,"IPv6Gateway":"","LinkLocalIPv6Address":"","LinkLocalIPv6PrefixLen":0,"MacAddress":"","NetworkID":"","PortMapping":null,"Ports":null,"SandboxKey":"","SecondaryIPAddresses":null,"SecondaryIPv6Addresses":null},"ResolvConfPath":"/var/lib/docker/containers/f780ee3f80e66e9b432a57049597118a66aab8932be88e5628d4c824edbee37c/resolv.conf","HostnamePath":"/var/lib/docker/containers/f780ee3f80e66e9b432a57049597118a66aab8932be88e5628d4c824edbee37c/hostname","HostsPath":"/var/lib/docker/containers/f780ee3f80e66e9b432a57049597118a66aab8932be88e5628d4c824edbee37c/hosts","LogPath":"/var/lib/docker/containers/f780ee3f80e66e9b432a57049597118a66aab8932be88e5628d4c824edbee37c/f780ee3f80e66e9b432a57049597118a66aab8932be88e5628d4c824edbee37c-json.log","Name":"/determined_euclid","Driver":"overlay","ExecDriver":"native-0.2","MountLabel":"","ProcessLabel":"","RestartCount":0,"UpdateDns":false,"HasBeenStartedBefore":false,"MountPoints":{},"Volumes":{},"VolumesRW":{},"AppArmorProfile":""}`)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// container with invalid image
+	err = addContainer(tmpdir, `{"State":{"Running":false,"Paused":false,"Restarting":false,"OOMKilled":false,"Dead":false,"Pid":0,"ExitCode":0,"Error":"","StartedAt":"2015-11-10T21:42:40.604267436Z","FinishedAt":"2015-11-10T21:42:41.869265487Z"},"ID":"e780ee3f80e66e9b432a57049597118a66aab8932be88e5628d4c824edbee37c","Created":"2015-11-10T21:42:40.433831551Z","Path":"sh","Args":[],"Config":{"Hostname":"f780ee3f80e6","Domainname":"","User":"","AttachStdin":true,"AttachStdout":true,"AttachStderr":true,"Tty":true,"OpenStdin":true,"StdinOnce":true,"Env":null,"Cmd":["sh"],"Image":"busybox","Volumes":null,"WorkingDir":"","Entrypoint":null,"OnBuild":null,"Labels":{}},"Image":"4c5ac3f849df8627fcf2822727f87c57f38b7129d3604fbc11d861fe856ff093","NetworkSettings":{"Bridge":"","EndpointID":"","Gateway":"","GlobalIPv6Address":"","GlobalIPv6PrefixLen":0,"HairpinMode":false,"IPAddress":"","IPPrefixLen":0,"IPv6Gateway":"","LinkLocalIPv6Address":"","LinkLocalIPv6PrefixLen":0,"MacAddress":"","NetworkID":"","PortMapping":null,"Ports":null,"SandboxKey":"","SecondaryIPAddresses":null,"SecondaryIPv6Addresses":null},"ResolvConfPath":"/var/lib/docker/containers/f780ee3f80e66e9b432a57049597118a66aab8932be88e5628d4c824edbee37c/resolv.conf","HostnamePath":"/var/lib/docker/containers/f780ee3f80e66e9b432a57049597118a66aab8932be88e5628d4c824edbee37c/hostname","HostsPath":"/var/lib/docker/containers/f780ee3f80e66e9b432a57049597118a66aab8932be88e5628d4c824edbee37c/hosts","LogPath":"/var/lib/docker/containers/f780ee3f80e66e9b432a57049597118a66aab8932be88e5628d4c824edbee37c/f780ee3f80e66e9b432a57049597118a66aab8932be88e5628d4c824edbee37c-json.log","Name":"/determined_euclid","Driver":"overlay","ExecDriver":"native-0.2","MountLabel":"","ProcessLabel":"","RestartCount":0,"UpdateDns":false,"HasBeenStartedBefore":false,"MountPoints":{},"Volumes":{},"VolumesRW":{},"AppArmorProfile":""}`)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	ls := &mockMounter{}
+
+	ifs, err := image.NewFSStoreBackend(filepath.Join(tmpdir, "imagedb"))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	is, err := image.NewImageStore(ifs, ls)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	imgID, err := is.Create([]byte(`{"architecture":"amd64","config":{"AttachStdin":false,"AttachStdout":false,"AttachStderr":false,"Cmd":["sh"],"Entrypoint":null,"Env":null,"Hostname":"23304fc829f9","Image":"d1592a710ac323612bd786fa8ac20727c58d8a67847e5a65177c594f43919498","Labels":null,"OnBuild":null,"OpenStdin":false,"StdinOnce":false,"Tty":false,"Volumes":null,"WorkingDir":"","Domainname":"","User":""},"container":"349b014153779e30093d94f6df2a43c7a0a164e05aa207389917b540add39b51","container_config":{"AttachStdin":false,"AttachStdout":false,"AttachStderr":false,"Cmd":["/bin/sh","-c","#(nop) CMD [\"sh\"]"],"Entrypoint":null,"Env":null,"Hostname":"23304fc829f9","Image":"d1592a710ac323612bd786fa8ac20727c58d8a67847e5a65177c594f43919498","Labels":null,"OnBuild":null,"OpenStdin":false,"StdinOnce":false,"Tty":false,"Volumes":null,"WorkingDir":"","Domainname":"","User":""},"created":"2015-10-31T22:22:55.613815829Z","docker_version":"1.8.2","history":[{"created":"2015-10-31T22:22:54.690851953Z","created_by":"/bin/sh -c #(nop) ADD file:a3bc1e842b69636f9df5256c49c5374fb4eef1e281fe3f282c65fb853ee171c5 in /"},{"created":"2015-10-31T22:22:55.613815829Z","created_by":"/bin/sh -c #(nop) CMD [\"sh\"]"}],"os":"linux","rootfs":{"type":"layers","diff_ids":["sha256:c6f988f4874bb0add23a778f753c65efe992244e148a1d2ec2a8b664fb66bbd1","sha256:5f70bf18a086007016e948b04aed3b82103a36bea41755b6cddfaf10ace3c6ef"]}}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = migrateContainers(tmpdir, ls, is, map[string]image.ID{
+		"2c5ac3f849df8627fcf2822727f87c57f38b7129d3604fbc11d861fe856ff093": imgID,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	expected := []mountInfo{{
+		"f780ee3f80e66e9b432a57049597118a66aab8932be88e5628d4c824edbee37c",
+		"f780ee3f80e66e9b432a57049597118a66aab8932be88e5628d4c824edbee37c",
+		"sha256:c3191d32a37d7159b2e30830937d2e30268ad6c375a773a8994911a3aba9b93f",
+	}}
+	if !reflect.DeepEqual(expected, ls.mounts) {
+		t.Fatalf("invalid mounts: expected %q, got %q", expected, ls.mounts)
+	}
+
+	if actual, expected := ls.count, 0; actual != expected {
+		t.Fatalf("invalid active mounts: expected %d, got %d", expected, actual)
+	}
+
+	config2, err := ioutil.ReadFile(filepath.Join(tmpdir, "containers", "f780ee3f80e66e9b432a57049597118a66aab8932be88e5628d4c824edbee37c", "config.v2.json"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	var config struct{ Image string }
+	err = json.Unmarshal(config2, &config)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if actual, expected := config.Image, string(imgID); actual != expected {
+		t.Fatalf("invalid image pointer in migrated config: expected %q, got %q", expected, actual)
+	}
+
+}
+
+func TestMigrateImages(t *testing.T) {
+	tmpdir, err := ioutil.TempDir("", "migrate-images")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmpdir)
+
+	// busybox from 1.9
+	id1, err := addImage(tmpdir, `{"architecture":"amd64","config":{"Hostname":"23304fc829f9","Domainname":"","User":"","AttachStdin":false,"AttachStdout":false,"AttachStderr":false,"Tty":false,"OpenStdin":false,"StdinOnce":false,"Env":null,"Cmd":null,"Image":"","Volumes":null,"WorkingDir":"","Entrypoint":null,"OnBuild":null,"Labels":null},"container":"23304fc829f9b9349416f6eb1afec162907eba3a328f51d53a17f8986f865d65","container_config":{"Hostname":"23304fc829f9","Domainname":"","User":"","AttachStdin":false,"AttachStdout":false,"AttachStderr":false,"Tty":false,"OpenStdin":false,"StdinOnce":false,"Env":null,"Cmd":["/bin/sh","-c","#(nop) ADD file:a3bc1e842b69636f9df5256c49c5374fb4eef1e281fe3f282c65fb853ee171c5 in /"],"Image":"","Volumes":null,"WorkingDir":"","Entrypoint":null,"OnBuild":null,"Labels":null},"created":"2015-10-31T22:22:54.690851953Z","docker_version":"1.8.2","layer_id":"sha256:55dc925c23d1ed82551fd018c27ac3ee731377b6bad3963a2a4e76e753d70e57","os":"linux"}`, "", "")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	id2, err := addImage(tmpdir, `{"architecture":"amd64","config":{"Hostname":"23304fc829f9","Domainname":"","User":"","AttachStdin":false,"AttachStdout":false,"AttachStderr":false,"Tty":false,"OpenStdin":false,"StdinOnce":false,"Env":null,"Cmd":["sh"],"Image":"d1592a710ac323612bd786fa8ac20727c58d8a67847e5a65177c594f43919498","Volumes":null,"WorkingDir":"","Entrypoint":null,"OnBuild":null,"Labels":null},"container":"349b014153779e30093d94f6df2a43c7a0a164e05aa207389917b540add39b51","container_config":{"Hostname":"23304fc829f9","Domainname":"","User":"","AttachStdin":false,"AttachStdout":false,"AttachStderr":false,"Tty":false,"OpenStdin":false,"StdinOnce":false,"Env":null,"Cmd":["/bin/sh","-c","#(nop) CMD [\"sh\"]"],"Image":"d1592a710ac323612bd786fa8ac20727c58d8a67847e5a65177c594f43919498","Volumes":null,"WorkingDir":"","Entrypoint":null,"OnBuild":null,"Labels":null},"created":"2015-10-31T22:22:55.613815829Z","docker_version":"1.8.2","layer_id":"sha256:a3ed95caeb02ffe68cdd9fd84406680ae93d633cb16422d00e8a7c22955b46d4","os":"linux","parent_id":"sha256:039b63dd2cbaa10d6015ea574392530571ed8d7b174090f032211285a71881d0"}`, id1, "")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	ls := &mockRegistrar{}
+
+	ifs, err := image.NewFSStoreBackend(filepath.Join(tmpdir, "imagedb"))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	is, err := image.NewImageStore(ifs, ls)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	ms, err := metadata.NewFSMetadataStore(filepath.Join(tmpdir, "distribution"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	mappings := make(map[string]image.ID)
+
+	err = migrateImages(tmpdir, ls, is, ms, mappings)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	expected := map[string]image.ID{
+		id1: image.ID("sha256:ca406eaf9c26898414ff5b7b3a023c33310759d6203be0663dbf1b3a712f432d"),
+		id2: image.ID("sha256:a488bec94bb96b26a968f913d25ef7d8d204d727ca328b52b4b059c7d03260b6"),
+	}
+
+	if !reflect.DeepEqual(mappings, expected) {
+		t.Fatalf("invalid image mappings: expected %q, got %q", expected, mappings)
+	}
+
+	if actual, expected := ls.count, 2; actual != expected {
+		t.Fatalf("invalid register count: expected %q, got %q", expected, actual)
+	}
+	ls.count = 0
+
+	// next images are busybox from 1.8.2
+	_, err = addImage(tmpdir, `{"id":"17583c7dd0dae6244203b8029733bdb7d17fccbb2b5d93e2b24cf48b8bfd06e2","parent":"d1592a710ac323612bd786fa8ac20727c58d8a67847e5a65177c594f43919498","created":"2015-10-31T22:22:55.613815829Z","container":"349b014153779e30093d94f6df2a43c7a0a164e05aa207389917b540add39b51","container_config":{"Hostname":"23304fc829f9","Domainname":"","User":"","AttachStdin":false,"AttachStdout":false,"AttachStderr":false,"ExposedPorts":null,"PublishService":"","Tty":false,"OpenStdin":false,"StdinOnce":false,"Env":null,"Cmd":["/bin/sh","-c","#(nop) CMD [\"sh\"]"],"Image":"d1592a710ac323612bd786fa8ac20727c58d8a67847e5a65177c594f43919498","Volumes":null,"VolumeDriver":"","WorkingDir":"","Entrypoint":null,"NetworkDisabled":false,"MacAddress":"","OnBuild":null,"Labels":null},"docker_version":"1.8.2","config":{"Hostname":"23304fc829f9","Domainname":"","User":"","AttachStdin":false,"AttachStdout":false,"AttachStderr":false,"ExposedPorts":null,"PublishService":"","Tty":false,"OpenStdin":false,"StdinOnce":false,"Env":null,"Cmd":["sh"],"Image":"d1592a710ac323612bd786fa8ac20727c58d8a67847e5a65177c594f43919498","Volumes":null,"VolumeDriver":"","WorkingDir":"","Entrypoint":null,"NetworkDisabled":false,"MacAddress":"","OnBuild":null,"Labels":null},"architecture":"amd64","os":"linux","Size":0}`, "", "sha256:a3ed95caeb02ffe68cdd9fd84406680ae93d633cb16422d00e8a7c22955b46d4")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, err = addImage(tmpdir, `{"id":"d1592a710ac323612bd786fa8ac20727c58d8a67847e5a65177c594f43919498","created":"2015-10-31T22:22:54.690851953Z","container":"23304fc829f9b9349416f6eb1afec162907eba3a328f51d53a17f8986f865d65","container_config":{"Hostname":"23304fc829f9","Domainname":"","User":"","AttachStdin":false,"AttachStdout":false,"AttachStderr":false,"ExposedPorts":null,"PublishService":"","Tty":false,"OpenStdin":false,"StdinOnce":false,"Env":null,"Cmd":["/bin/sh","-c","#(nop) ADD file:a3bc1e842b69636f9df5256c49c5374fb4eef1e281fe3f282c65fb853ee171c5 in /"],"Image":"","Volumes":null,"VolumeDriver":"","WorkingDir":"","Entrypoint":null,"NetworkDisabled":false,"MacAddress":"","OnBuild":null,"Labels":null},"docker_version":"1.8.2","config":{"Hostname":"23304fc829f9","Domainname":"","User":"","AttachStdin":false,"AttachStdout":false,"AttachStderr":false,"ExposedPorts":null,"PublishService":"","Tty":false,"OpenStdin":false,"StdinOnce":false,"Env":null,"Cmd":null,"Image":"","Volumes":null,"VolumeDriver":"","WorkingDir":"","Entrypoint":null,"NetworkDisabled":false,"MacAddress":"","OnBuild":null,"Labels":null},"architecture":"amd64","os":"linux","Size":1108935}`, "", "sha256:55dc925c23d1ed82551fd018c27ac3ee731377b6bad3963a2a4e76e753d70e57")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = migrateImages(tmpdir, ls, is, ms, mappings)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	expected["d1592a710ac323612bd786fa8ac20727c58d8a67847e5a65177c594f43919498"] = image.ID("sha256:c091bb33854e57e6902b74c08719856d30b5593c7db6143b2b48376b8a588395")
+	expected["17583c7dd0dae6244203b8029733bdb7d17fccbb2b5d93e2b24cf48b8bfd06e2"] = image.ID("sha256:d963020e755ff2715b936065949472c1f8a6300144b922992a1a421999e71f07")
+
+	if actual, expected := ls.count, 2; actual != expected {
+		t.Fatalf("invalid register count: expected %q, got %q", expected, actual)
+	}
+
+	blobSumService := metadata.NewBlobSumService(ms)
+	blobsums, err := blobSumService.GetBlobSums(layer.EmptyLayer.DiffID())
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	expectedBlobsums := []digest.Digest{
+		"sha256:55dc925c23d1ed82551fd018c27ac3ee731377b6bad3963a2a4e76e753d70e57",
+		"sha256:a3ed95caeb02ffe68cdd9fd84406680ae93d633cb16422d00e8a7c22955b46d4",
+	}
+
+	if !reflect.DeepEqual(expectedBlobsums, blobsums) {
+		t.Fatalf("invalid blobsums: expected %q, got %q", expectedBlobsums, blobsums)
+	}
+
+}
+
+func TestMigrateUnsupported(t *testing.T) {
+	tmpdir, err := ioutil.TempDir("", "migrate-empty")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmpdir)
+
+	err = Migrate(tmpdir, "generic", nil, nil, nil, nil)
+	if err != errUnsupported {
+		t.Fatalf("expected unsupported error, got %q", err)
+	}
+}
+
+func addImage(dest, jsonConfig, parent, checksum string) (string, error) {
+	var config struct{ ID string }
+	if err := json.Unmarshal([]byte(jsonConfig), &config); err != nil {
+		return "", err
+	}
+	if config.ID == "" {
+		b := make([]byte, 32)
+		rand.Read(b)
+		config.ID = hex.EncodeToString(b)
+	}
+	contDir := filepath.Join(dest, "graph", config.ID)
+	if err := os.MkdirAll(contDir, 0700); err != nil {
+		return "", err
+	}
+	if err := ioutil.WriteFile(filepath.Join(contDir, "json"), []byte(jsonConfig), 0600); err != nil {
+		return "", err
+	}
+	if parent != "" {
+		if err := ioutil.WriteFile(filepath.Join(contDir, "parent"), []byte(parent), 0600); err != nil {
+			return "", err
+		}
+	}
+	if checksum != "" {
+		if err := ioutil.WriteFile(filepath.Join(contDir, "checksum"), []byte(checksum), 0600); err != nil {
+			return "", err
+		}
+	}
+	return config.ID, nil
+}
+
+func addContainer(dest, jsonConfig string) error {
+	var config struct{ ID string }
+	if err := json.Unmarshal([]byte(jsonConfig), &config); err != nil {
+		return err
+	}
+	contDir := filepath.Join(dest, "containers", config.ID)
+	if err := os.MkdirAll(contDir, 0700); err != nil {
+		return err
+	}
+	if err := ioutil.WriteFile(filepath.Join(contDir, "config.json"), []byte(jsonConfig), 0600); err != nil {
+		return err
+	}
+	return nil
+}
+
+type mockTagAdder struct {
+	refs map[string]string
+}
+
+func (t *mockTagAdder) Add(ref reference.Named, id image.ID, force bool) error {
+	if t.refs == nil {
+		t.refs = make(map[string]string)
+	}
+	t.refs[ref.String()] = id.String()
+	return nil
+}
+
+type mockRegistrar struct {
+	layers map[layer.ChainID]*mockLayer
+	count  int
+}
+
+func (r *mockRegistrar) RegisterByGraphID(graphID string, parent layer.ChainID, tarDataFile string) (layer.Layer, error) {
+	r.count++
+	l := &mockLayer{}
+	if parent != "" {
+		p, exists := r.layers[parent]
+		if !exists {
+			return nil, fmt.Errorf("invalid parent %q", parent)
+		}
+		l.parent = p
+		l.diffIDs = append(l.diffIDs, p.diffIDs...)
+	}
+	l.diffIDs = append(l.diffIDs, layer.EmptyLayer.DiffID())
+	if r.layers == nil {
+		r.layers = make(map[layer.ChainID]*mockLayer)
+	}
+	r.layers[l.ChainID()] = l
+	return l, nil
+}
+func (r *mockRegistrar) Release(l layer.Layer) ([]layer.Metadata, error) {
+	return nil, nil
+}
+func (r *mockRegistrar) Get(layer.ChainID) (layer.Layer, error) {
+	return nil, nil
+}
+
+type mountInfo struct {
+	name, graphID, parent string
+}
+type mockMounter struct {
+	mounts []mountInfo
+	count  int
+}
+
+func (r *mockMounter) MountByGraphID(name string, graphID string, parent layer.ChainID) (layer.RWLayer, error) {
+	r.mounts = append(r.mounts, mountInfo{name, graphID, string(parent)})
+	r.count++
+	return nil, nil
+}
+func (r *mockMounter) Unmount(string) error {
+	r.count--
+	return nil
+}
+func (r *mockMounter) Get(layer.ChainID) (layer.Layer, error) {
+	return nil, nil
+}
+
+func (r *mockMounter) Release(layer.Layer) ([]layer.Metadata, error) {
+	return nil, nil
+}
+
+type mockLayer struct {
+	diffIDs []layer.DiffID
+	parent  *mockLayer
+}
+
+func (l *mockLayer) TarStream() (io.Reader, error) {
+	return nil, nil
+}
+
+func (l *mockLayer) ChainID() layer.ChainID {
+	return layer.CreateChainID(l.diffIDs)
+}
+
+func (l *mockLayer) DiffID() layer.DiffID {
+	return l.diffIDs[len(l.diffIDs)-1]
+}
+
+func (l *mockLayer) Parent() layer.Layer {
+	if l.parent == nil {
+		return nil
+	}
+	return l.parent
+}
+
+func (l *mockLayer) Size() (int64, error) {
+	return 0, nil
+}
+
+func (l *mockLayer) DiffSize() (int64, error) {
+	return 0, nil
+}
+
+func (l *mockLayer) Metadata() (map[string]string, error) {
+	return nil, nil
+}