Merge ce22b34c6d into 7b69d43198

cmd/kpod/containerImageRef.go

@@ -208,7 +208,7 @@ func (i *containerImageRef) NewImageSource(sc *types.SystemContext, manifestType
 			continue
 		}
 		// Start reading the layer.
-		rc, err := i.store.Diff("", layerID)
+		rc, err := i.store.Diff("", layerID, nil)
 		if err != nil {
 			return nil, errors.Wrapf(err, "error extracting layer %q", layerID)
 		}

vendor.conf

@@ -5,8 +5,8 @@ k8s.io/apimachinery release-1.6 https://github.com/kubernetes/apimachinery
 k8s.io/apiserver release-1.6 https://github.com/kubernetes/apiserver
 #
 github.com/Sirupsen/logrus v0.11.5
-github.com/containers/image cd150088f25d1ac81c6dff3a0bf458725cb8b339
+github.com/containers/image c2a797dfe5bb4a9dd7f48332ce40c6223ffba492
-github.com/containers/storage 2c75d14b978bff468e7d5ec3ff8a003eca443209
+github.com/containers/storage 5d8c2f87387fa5be9fa526ae39fbd79b8bdf27be
 github.com/containernetworking/cni v0.4.0
 google.golang.org/grpc v1.0.1-GA https://github.com/grpc/grpc-go
 github.com/opencontainers/selinux v1.0.0-rc1

vendor/github.com/containers/image/README.md

@@ -51,14 +51,20 @@ Ensure that the dependencies documented [in vendor.conf](https://github.com/cont
 are also available
 (using those exact versions or different versions of your choosing).
 
-This library, by default, also depends on the GpgME C library. Either install it:
+This library, by default, also depends on the GpgME and libostree C libraries. Either install them:
 ```sh
-Fedora$ dnf install gpgme-devel libassuan-devel
+Fedora$ dnf install gpgme-devel libassuan-devel libostree-devel
 macOS$ brew install gpgme
 ```
-or use the `containers_image_openpgp` build tag (e.g. using `go build -tags …`)
+or use the build tags described below to avoid the dependencies (e.g. using `go build -tags …`)
-This will use a Golang-only OpenPGP implementation for signature verification instead of the default cgo/gpgme-based implementation;
+
+### Supported build tags
+
+- `containers_image_openpgp`: Use a Golang-only OpenPGP implementation for signature verification instead of the default cgo/gpgme-based implementation;
 the primary downside is that creating new signatures with the Golang-only implementation is not supported.
+- `containers_image_ostree_stub`: Instead of importing `ostree:` transport in `github.com/containers/image/transports/alltransports`, use a stub which reports that the transport is not supported. This allows building the library without requiring the `libostree` development libraries.
+
+  (Note that explicitly importing `github.com/containers/image/ostree` will still depend on the `libostree` library, this build tag only affects generic users of …`/alltransports`.)
 
 ## Contributing
 

vendor/github.com/containers/image/copy/copy.go

@@ -7,6 +7,7 @@ import (
 	"io"
 	"io/ioutil"
 	"reflect"
+	"runtime"
 	"strings"
 	"time"
 
@@ -157,6 +158,10 @@ func Image(policyContext *signature.PolicyContext, destRef, srcRef types.ImageRe
 		}
 	}()
 
+	if err := checkImageDestinationForCurrentRuntimeOS(src, dest); err != nil {
+		return err
+	}
+
 	if src.IsMultiImage() {
 		return errors.Errorf("can not copy %s: manifest contains multiple images", transports.ImageName(srcRef))
 	}
@@ -277,6 +282,22 @@ func Image(policyContext *signature.PolicyContext, destRef, srcRef types.ImageRe
 	return nil
 }
 
+func checkImageDestinationForCurrentRuntimeOS(src types.Image, dest types.ImageDestination) error {
+	if dest.MustMatchRuntimeOS() {
+		c, err := src.OCIConfig()
+		if err != nil {
+			return errors.Wrapf(err, "Error parsing image configuration")
+		}
+		osErr := fmt.Errorf("image operating system %q cannot be used on %q", c.OS, runtime.GOOS)
+		if runtime.GOOS == "windows" && c.OS == "linux" {
+			return osErr
+		} else if runtime.GOOS != "windows" && c.OS == "windows" {
+			return osErr
+		}
+	}
+	return nil
+}
+
 // updateEmbeddedDockerReference handles the Docker reference embedded in Docker schema1 manifests.
 func updateEmbeddedDockerReference(manifestUpdates *types.ManifestUpdateOptions, dest types.ImageDestination, src types.Image, canModifyManifest bool) error {
 	destRef := dest.Reference().DockerReference()

vendor/github.com/containers/image/directory/directory_dest.go

@@ -51,6 +51,11 @@ func (d *dirImageDestination) AcceptsForeignLayerURLs() bool {
 	return false
 }
 
+// MustMatchRuntimeOS returns true iff the destination can store only images targeted for the current runtime OS. False otherwise.
+func (d *dirImageDestination) MustMatchRuntimeOS() bool {
+	return false
+}
+
 // PutBlob writes contents of stream and returns data representing the result (with all data filled in).
 // inputInfo.Digest can be optionally provided if known; it is not mandatory for the implementation to verify it.
 // inputInfo.Size is the expected length of stream, if known.

vendor/github.com/containers/image/docker/daemon/daemon_dest.go

@@ -78,6 +78,11 @@ func imageLoadGoroutine(ctx context.Context, c *client.Client, reader *io.PipeRe
 	defer resp.Body.Close()
 }
 
+// MustMatchRuntimeOS returns true iff the destination can store only images targeted for the current runtime OS. False otherwise.
+func (d *daemonImageDestination) MustMatchRuntimeOS() bool {
+	return true
+}
+
 // Close removes resources associated with an initialized ImageDestination, if any.
 func (d *daemonImageDestination) Close() error {
 	if !d.committed {

vendor/github.com/containers/image/docker/docker_client.go

@@ -308,31 +308,36 @@ func (c *dockerClient) setupRequestAuth(req *http.Request) error {
 	if len(c.challenges) == 0 {
 		return nil
 	}
-	// assume just one...
+	schemeNames := make([]string, 0, len(c.challenges))
-	challenge := c.challenges[0]
+	for _, challenge := range c.challenges {
-	switch challenge.Scheme {
+		schemeNames = append(schemeNames, challenge.Scheme)
-	case "basic":
+		switch challenge.Scheme {
-		req.SetBasicAuth(c.username, c.password)
+		case "basic":
-		return nil
+			req.SetBasicAuth(c.username, c.password)
-	case "bearer":
+			return nil
-		if c.token == nil || time.Now().After(c.tokenExpiration) {
+		case "bearer":
-			realm, ok := challenge.Parameters["realm"]
+			if c.token == nil || time.Now().After(c.tokenExpiration) {
-			if !ok {
+				realm, ok := challenge.Parameters["realm"]
-				return errors.Errorf("missing realm in bearer auth challenge")
+				if !ok {
+					return errors.Errorf("missing realm in bearer auth challenge")
+				}
+				service, _ := challenge.Parameters["service"] // Will be "" if not present
+				scope := fmt.Sprintf("repository:%s:%s", c.scope.remoteName, c.scope.actions)
+				token, err := c.getBearerToken(realm, service, scope)
+				if err != nil {
+					return err
+				}
+				c.token = token
+				c.tokenExpiration = token.IssuedAt.Add(time.Duration(token.ExpiresIn) * time.Second)
 			}
-			service, _ := challenge.Parameters["service"] // Will be "" if not present
+			req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", c.token.Token))
-			scope := fmt.Sprintf("repository:%s:%s", c.scope.remoteName, c.scope.actions)
+			return nil
-			token, err := c.getBearerToken(realm, service, scope)
+		default:
-			if err != nil {
+			logrus.Debugf("no handler for %s authentication", challenge.Scheme)
-				return err
-			}
-			c.token = token
-			c.tokenExpiration = token.IssuedAt.Add(time.Duration(token.ExpiresIn) * time.Second)
 		}
-		req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", c.token.Token))
-		return nil
 	}
-	return errors.Errorf("no handler for %s authentication", challenge.Scheme)
+	logrus.Infof("None of the challenges sent by server (%s) are supported, trying an unauthenticated request anyway", strings.Join(schemeNames, ", "))
+	return nil
 }
 
 func (c *dockerClient) getBearerToken(realm, service, scope string) (*bearerToken, error) {

vendor/github.com/containers/image/docker/docker_image_dest.go

@@ -99,6 +99,11 @@ func (d *dockerImageDestination) AcceptsForeignLayerURLs() bool {
 	return true
 }
 
+// MustMatchRuntimeOS returns true iff the destination can store only images targeted for the current runtime OS. False otherwise.
+func (d *dockerImageDestination) MustMatchRuntimeOS() bool {
+	return false
+}
+
 // sizeCounter is an io.Writer which only counts the total size of its input.
 type sizeCounter struct{ size int64 }
 

vendor/github.com/containers/image/docker/tarfile/dest.go

@@ -81,6 +81,11 @@ func (d *Destination) AcceptsForeignLayerURLs() bool {
 	return false
 }
 
+// MustMatchRuntimeOS returns true iff the destination can store only images targeted for the current runtime OS. False otherwise.
+func (d *Destination) MustMatchRuntimeOS() bool {
+	return false
+}
+
 // PutBlob writes contents of stream and returns data representing the result (with all data filled in).
 // inputInfo.Digest can be optionally provided if known; it is not mandatory for the implementation to verify it.
 // inputInfo.Size is the expected length of stream, if known.
@@ -176,7 +181,7 @@ func (d *Destination) PutManifest(m []byte) error {
 		layerPaths = append(layerPaths, l.Digest.String())
 	}
 
-	items := []manifestItem{{
+	items := []ManifestItem{{
 		Config:       man.Config.Digest.String(),
 		RepoTags:     []string{d.repoTag},
 		Layers:       layerPaths,

vendor/github.com/containers/image/docker/tarfile/src.go

@@ -20,7 +20,7 @@ import (
 type Source struct {
 	tarPath string
 	// The following data is only available after ensureCachedDataIsPresent() succeeds
-	tarManifest       *manifestItem // nil if not available yet.
+	tarManifest       *ManifestItem // nil if not available yet.
 	configBytes       []byte
 	configDigest      digest.Digest
 	orderedDiffIDList []diffID
@@ -145,23 +145,28 @@ func (s *Source) ensureCachedDataIsPresent() error {
 		return err
 	}
 
+	// Check to make sure length is 1
+	if len(tarManifest) != 1 {
+		return errors.Errorf("Unexpected tar manifest.json: expected 1 item, got %d", len(tarManifest))
+	}
+
 	// Read and parse config.
-	configBytes, err := s.readTarComponent(tarManifest.Config)
+	configBytes, err := s.readTarComponent(tarManifest[0].Config)
 	if err != nil {
 		return err
 	}
 	var parsedConfig image // Most fields ommitted, we only care about layer DiffIDs.
 	if err := json.Unmarshal(configBytes, &parsedConfig); err != nil {
-		return errors.Wrapf(err, "Error decoding tar config %s", tarManifest.Config)
+		return errors.Wrapf(err, "Error decoding tar config %s", tarManifest[0].Config)
 	}
 
-	knownLayers, err := s.prepareLayerData(tarManifest, &parsedConfig)
+	knownLayers, err := s.prepareLayerData(&tarManifest[0], &parsedConfig)
 	if err != nil {
 		return err
 	}
 
 	// Success; commit.
-	s.tarManifest = tarManifest
+	s.tarManifest = &tarManifest[0]
 	s.configBytes = configBytes
 	s.configDigest = digest.FromBytes(configBytes)
 	s.orderedDiffIDList = parsedConfig.RootFS.DiffIDs
@@ -170,23 +175,25 @@ func (s *Source) ensureCachedDataIsPresent() error {
 }
 
 // loadTarManifest loads and decodes the manifest.json.
-func (s *Source) loadTarManifest() (*manifestItem, error) {
+func (s *Source) loadTarManifest() ([]ManifestItem, error) {
 	// FIXME? Do we need to deal with the legacy format?
 	bytes, err := s.readTarComponent(manifestFileName)
 	if err != nil {
 		return nil, err
 	}
-	var items []manifestItem
+	var items []ManifestItem
 	if err := json.Unmarshal(bytes, &items); err != nil {
 		return nil, errors.Wrap(err, "Error decoding tar manifest.json")
 	}
-	if len(items) != 1 {
+	return items, nil
-		return nil, errors.Errorf("Unexpected tar manifest.json: expected 1 item, got %d", len(items))
-	}
-	return &items[0], nil
 }
 
-func (s *Source) prepareLayerData(tarManifest *manifestItem, parsedConfig *image) (map[diffID]*layerInfo, error) {
+// LoadTarManifest loads and decodes the manifest.json
+func (s *Source) LoadTarManifest() ([]ManifestItem, error) {
+	return s.loadTarManifest()
+}
+
+func (s *Source) prepareLayerData(tarManifest *ManifestItem, parsedConfig *image) (map[diffID]*layerInfo, error) {
 	// Collect layer data available in manifest and config.
 	if len(tarManifest.Layers) != len(parsedConfig.RootFS.DiffIDs) {
 		return nil, errors.Errorf("Inconsistent layer count: %d in manifest, %d in config", len(tarManifest.Layers), len(parsedConfig.RootFS.DiffIDs))

vendor/github.com/containers/image/docker/tarfile/types.go

@@ -13,7 +13,8 @@ const (
 	// legacyRepositoriesFileName = "repositories"
 )
 
-type manifestItem struct {
+// ManifestItem is an element of the array stored in the top-level manifest.json file.
+type ManifestItem struct {
 	Config       string
 	RepoTags     []string
 	Layers       []string

vendor/github.com/containers/image/image/docker_list.go

@@ -16,7 +16,7 @@ type platformSpec struct {
 	OSVersion    string   `json:"os.version,omitempty"`
 	OSFeatures   []string `json:"os.features,omitempty"`
 	Variant      string   `json:"variant,omitempty"`
-	Features     []string `json:"features,omitempty"`
+	Features     []string `json:"features,omitempty"` // removed in OCI
 }
 
 // A manifestDescriptor references a platform-specific manifest.

vendor/github.com/containers/image/image/docker_schema2.go

@@ -183,6 +183,7 @@ func (m *manifestSchema2) UpdatedImage(options types.ManifestUpdateOptions) (typ
 		}
 		copy.LayersDescriptors = make([]descriptor, len(options.LayerInfos))
 		for i, info := range options.LayerInfos {
+			copy.LayersDescriptors[i].MediaType = m.LayersDescriptors[i].MediaType
 			copy.LayersDescriptors[i].Digest = info.Digest
 			copy.LayersDescriptors[i].Size = info.Size
 			copy.LayersDescriptors[i].URLs = info.URLs
@@ -213,15 +214,17 @@ func (m *manifestSchema2) convertToManifestOCI1() (types.Image, error) {
 		return nil, err
 	}
 
-	config := descriptor{
+	config := descriptorOCI1{
-		MediaType: imgspecv1.MediaTypeImageConfig,
+		descriptor: descriptor{
-		Size:      int64(len(configOCIBytes)),
+			MediaType: imgspecv1.MediaTypeImageConfig,
-		Digest:    digest.FromBytes(configOCIBytes),
+			Size:      int64(len(configOCIBytes)),
+			Digest:    digest.FromBytes(configOCIBytes),
+		},
 	}
 
-	layers := make([]descriptor, len(m.LayersDescriptors))
+	layers := make([]descriptorOCI1, len(m.LayersDescriptors))
 	for idx := range layers {
-		layers[idx] = m.LayersDescriptors[idx]
+		layers[idx] = descriptorOCI1{descriptor: m.LayersDescriptors[idx]}
 		if m.LayersDescriptors[idx].MediaType == manifest.DockerV2Schema2ForeignLayerMediaType {
 			layers[idx].MediaType = imgspecv1.MediaTypeImageLayerNonDistributable
 		} else {

vendor/github.com/containers/image/image/oci.go

@@ -12,12 +12,18 @@ import (
 	"github.com/pkg/errors"
 )
 
+type descriptorOCI1 struct {
+	descriptor
+	Annotations map[string]string `json:"annotations,omitempty"`
+}
+
 type manifestOCI1 struct {
 	src               types.ImageSource // May be nil if configBlob is not nil
 	configBlob        []byte            // If set, corresponds to contents of ConfigDescriptor.
 	SchemaVersion     int               `json:"schemaVersion"`
-	ConfigDescriptor  descriptor        `json:"config"`
+	ConfigDescriptor  descriptorOCI1    `json:"config"`
-	LayersDescriptors []descriptor      `json:"layers"`
+	LayersDescriptors []descriptorOCI1  `json:"layers"`
+	Annotations       map[string]string `json:"annotations,omitempty"`
 }
 
 func manifestOCI1FromManifest(src types.ImageSource, manifest []byte) (genericManifest, error) {
@@ -29,7 +35,7 @@ func manifestOCI1FromManifest(src types.ImageSource, manifest []byte) (genericMa
 }
 
 // manifestOCI1FromComponents builds a new manifestOCI1 from the supplied data:
-func manifestOCI1FromComponents(config descriptor, src types.ImageSource, configBlob []byte, layers []descriptor) genericManifest {
+func manifestOCI1FromComponents(config descriptorOCI1, src types.ImageSource, configBlob []byte, layers []descriptorOCI1) genericManifest {
 	return &manifestOCI1{
 		src:               src,
 		configBlob:        configBlob,
@@ -148,8 +154,9 @@ func (m *manifestOCI1) UpdatedImage(options types.ManifestUpdateOptions) (types.
 		if len(copy.LayersDescriptors) != len(options.LayerInfos) {
 			return nil, errors.Errorf("Error preparing updated manifest: layer count changed from %d to %d", len(copy.LayersDescriptors), len(options.LayerInfos))
 		}
-		copy.LayersDescriptors = make([]descriptor, len(options.LayerInfos))
+		copy.LayersDescriptors = make([]descriptorOCI1, len(options.LayerInfos))
 		for i, info := range options.LayerInfos {
+			copy.LayersDescriptors[i].MediaType = m.LayersDescriptors[i].MediaType
 			copy.LayersDescriptors[i].Digest = info.Digest
 			copy.LayersDescriptors[i].Size = info.Size
 		}
@@ -169,7 +176,7 @@ func (m *manifestOCI1) UpdatedImage(options types.ManifestUpdateOptions) (types.
 
 func (m *manifestOCI1) convertToManifestSchema2() (types.Image, error) {
 	// Create a copy of the descriptor.
-	config := m.ConfigDescriptor
+	config := m.ConfigDescriptor.descriptor
 
 	// The only difference between OCI and DockerSchema2 is the mediatypes. The
 	// media type of the manifest is handled by manifestSchema2FromComponents.
@@ -177,7 +184,7 @@ func (m *manifestOCI1) convertToManifestSchema2() (types.Image, error) {
 
 	layers := make([]descriptor, len(m.LayersDescriptors))
 	for idx := range layers {
-		layers[idx] = m.LayersDescriptors[idx]
+		layers[idx] = m.LayersDescriptors[idx].descriptor
 		layers[idx].MediaType = manifest.DockerV2Schema2LayerMediaType
 	}
 

vendor/github.com/containers/image/oci/layout/oci_dest.go

@@ -66,6 +66,11 @@ func (d *ociImageDestination) AcceptsForeignLayerURLs() bool {
 	return false
 }
 
+// MustMatchRuntimeOS returns true iff the destination can store only images targeted for the current runtime OS. False otherwise.
+func (d *ociImageDestination) MustMatchRuntimeOS() bool {
+	return false
+}
+
 // PutBlob writes contents of stream and returns data representing the result (with all data filled in).
 // inputInfo.Digest can be optionally provided if known; it is not mandatory for the implementation to verify it.
 // inputInfo.Size is the expected length of stream, if known.

vendor/github.com/containers/image/openshift/openshift.go

@@ -358,6 +358,11 @@ func (d *openshiftImageDestination) AcceptsForeignLayerURLs() bool {
 	return true
 }
 
+// MustMatchRuntimeOS returns true iff the destination can store only images targeted for the current runtime OS. False otherwise.
+func (d *openshiftImageDestination) MustMatchRuntimeOS() bool {
+	return false
+}
+
 // PutBlob writes contents of stream and returns data representing the result (with all data filled in).
 // inputInfo.Digest can be optionally provided if known; it is not mandatory for the implementation to verify it.
 // inputInfo.Size is the expected length of stream, if known.

vendor/github.com/containers/image/ostree/ostree_dest.go

@@ -11,12 +11,15 @@ import (
 	"path/filepath"
 	"strconv"
 	"strings"
+	"time"
 
 	"github.com/containers/image/manifest"
 	"github.com/containers/image/types"
 	"github.com/containers/storage/pkg/archive"
 	"github.com/opencontainers/go-digest"
 	"github.com/pkg/errors"
+
+	"github.com/ostreedev/ostree-go/pkg/otbuiltin"
 )
 
 type blobToImport struct {
@@ -86,6 +89,11 @@ func (d *ostreeImageDestination) AcceptsForeignLayerURLs() bool {
 	return false
 }
 
+// MustMatchRuntimeOS returns true iff the destination can store only images targeted for the current runtime OS. False otherwise.
+func (d *ostreeImageDestination) MustMatchRuntimeOS() bool {
+	return true
+}
+
 func (d *ostreeImageDestination) PutBlob(stream io.Reader, inputInfo types.BlobInfo) (types.BlobInfo, error) {
 	tmpDir, err := ioutil.TempDir(d.tmpDirPath, "blob")
 	if err != nil {
@@ -153,7 +161,17 @@ func fixFiles(dir string, usermode bool) error {
 	return nil
 }
 
-func (d *ostreeImageDestination) importBlob(blob *blobToImport) error {
+func (d *ostreeImageDestination) ostreeCommit(repo *otbuiltin.Repo, branch string, root string, metadata []string) error {
+	opts := otbuiltin.NewCommitOptions()
+	opts.AddMetadataString = metadata
+	opts.Timestamp = time.Now()
+	// OCI layers have no parent OSTree commit
+	opts.Parent = "0000000000000000000000000000000000000000000000000000000000000000"
+	_, err := repo.Commit(root, branch, opts)
+	return err
+}
+
+func (d *ostreeImageDestination) importBlob(repo *otbuiltin.Repo, blob *blobToImport) error {
 	ostreeBranch := fmt.Sprintf("ociimage/%s", blob.Digest.Hex())
 	destinationPath := filepath.Join(d.tmpDirPath, blob.Digest.Hex(), "root")
 	if err := ensureDirectoryExists(destinationPath); err != nil {
@@ -181,11 +199,7 @@ func (d *ostreeImageDestination) importBlob(blob *blobToImport) error {
 			return err
 		}
 	}
-	return exec.Command("ostree", "commit",
+	return d.ostreeCommit(repo, ostreeBranch, destinationPath, []string{fmt.Sprintf("docker.size=%d", blob.Size)})
-		"--repo", d.ref.repo,
-		fmt.Sprintf("--add-metadata-string=docker.size=%d", blob.Size),
-		"--branch", ostreeBranch,
-		fmt.Sprintf("--tree=dir=%s", destinationPath)).Run()
 }
 
 func (d *ostreeImageDestination) importConfig(blob *blobToImport) error {
@@ -253,6 +267,16 @@ func (d *ostreeImageDestination) PutSignatures(signatures [][]byte) error {
 }
 
 func (d *ostreeImageDestination) Commit() error {
+	repo, err := otbuiltin.OpenRepo(d.ref.repo)
+	if err != nil {
+		return err
+	}
+
+	_, err = repo.PrepareTransaction()
+	if err != nil {
+		return err
+	}
+
 	for _, layer := range d.schema.LayersDescriptors {
 		hash := layer.Digest.Hex()
 		blob := d.blobs[hash]
@@ -261,7 +285,7 @@ func (d *ostreeImageDestination) Commit() error {
 		if blob == nil {
 			continue
 		}
-		err := d.importBlob(blob)
+		err := d.importBlob(repo, blob)
 		if err != nil {
 			return err
 		}
@@ -277,11 +301,11 @@ func (d *ostreeImageDestination) Commit() error {
 	}
 
 	manifestPath := filepath.Join(d.tmpDirPath, "manifest")
-	err := exec.Command("ostree", "commit",
+
-		"--repo", d.ref.repo,
+	metadata := []string{fmt.Sprintf("docker.manifest=%s", string(d.manifest))}
-		fmt.Sprintf("--add-metadata-string=docker.manifest=%s", string(d.manifest)),
+	err = d.ostreeCommit(repo, fmt.Sprintf("ociimage/%s", d.ref.branchName), manifestPath, metadata)
-		fmt.Sprintf("--branch=ociimage/%s", d.ref.branchName),
+
-		manifestPath).Run()
+	_, err = repo.CommitTransaction()
 	return err
 }
 

vendor/github.com/containers/image/storage/storage_image.go

@@ -174,11 +174,11 @@ func (s *storageImageDestination) putBlob(stream io.Reader, blobinfo types.BlobI
 		}
 		// Attempt to create the identified layer and import its contents.
 		layer, uncompressedSize, err := s.imageRef.transport.store.PutLayer(id, parentLayer, nil, "", true, multi)
-		if err != nil && err != storage.ErrDuplicateID {
+		if err != nil && errors.Cause(err) != storage.ErrDuplicateID {
 			logrus.Debugf("error importing layer blob %q as %q: %v", blobinfo.Digest, id, err)
 			return errorBlobInfo, err
 		}
-		if err == storage.ErrDuplicateID {
+		if errors.Cause(err) == storage.ErrDuplicateID {
 			// We specified an ID, and there's already a layer with
 			// the same ID.  Drain the input so that we can look at
 			// its length and digest.
@@ -291,7 +291,7 @@ func (s *storageImageDestination) PutBlob(stream io.Reader, blobinfo types.BlobI
 // it returns a non-nil error only on an unexpected failure.
 func (s *storageImageDestination) HasBlob(blobinfo types.BlobInfo) (bool, int64, error) {
 	if blobinfo.Digest == "" {
-		return false, -1, errors.Errorf(`"Can not check for a blob with unknown digest`)
+		return false, -1, errors.Errorf(`Can not check for a blob with unknown digest`)
 	}
 	for _, blob := range s.BlobList {
 		if blob.Digest == blobinfo.Digest {
@@ -331,7 +331,7 @@ func (s *storageImageDestination) Commit() error {
 	}
 	img, err := s.imageRef.transport.store.CreateImage(s.ID, nil, lastLayer, "", nil)
 	if err != nil {
-		if err != storage.ErrDuplicateID {
+		if errors.Cause(err) != storage.ErrDuplicateID {
 			logrus.Debugf("error creating image: %q", err)
 			return errors.Wrapf(err, "error creating image %q", s.ID)
 		}
@@ -340,8 +340,8 @@ func (s *storageImageDestination) Commit() error {
 			return errors.Wrapf(err, "error reading image %q", s.ID)
 		}
 		if img.TopLayer != lastLayer {
-			logrus.Debugf("error creating image: image with ID %q exists, but uses different layers", err)
+			logrus.Debugf("error creating image: image with ID %q exists, but uses different layers", s.ID)
-			return errors.Wrapf(err, "image with ID %q already exists, but uses a different top layer", s.ID)
+			return errors.Wrapf(storage.ErrDuplicateID, "image with ID %q already exists, but uses a different top layer", s.ID)
 		}
 		logrus.Debugf("reusing image ID %q", img.ID)
 	} else {
@@ -449,6 +449,11 @@ func (s *storageImageDestination) AcceptsForeignLayerURLs() bool {
 	return false
 }
 
+// MustMatchRuntimeOS returns true iff the destination can store only images targeted for the current runtime OS. False otherwise.
+func (s *storageImageDestination) MustMatchRuntimeOS() bool {
+	return true
+}
+
 func (s *storageImageDestination) PutSignatures(signatures [][]byte) error {
 	sizes := []int{}
 	sigblob := []byte{}
@@ -516,7 +521,7 @@ func diffLayer(store storage.Store, layerID string) (rc io.ReadCloser, n int64,
 	} else {
 		n = layerMeta.CompressedSize
 	}
-	diff, err := store.Diff("", layer.ID)
+	diff, err := store.Diff("", layer.ID, nil)
 	if err != nil {
 		return nil, -1, err
 	}

vendor/github.com/containers/image/storage/storage_reference.go

@@ -70,7 +70,9 @@ func (s *storageReference) resolveImage() (*storage.Image, error) {
 // to build this reference object.
 func (s storageReference) Transport() types.ImageTransport {
 	return &storageTransport{
-		store: s.transport.store,
+		store:         s.transport.store,
+		defaultUIDMap: s.transport.defaultUIDMap,
+		defaultGIDMap: s.transport.defaultGIDMap,
 	}
 }
 
@@ -83,7 +85,12 @@ func (s storageReference) DockerReference() reference.Named {
 // disambiguate between images which may be present in multiple stores and
 // share only their names.
 func (s storageReference) StringWithinTransport() string {
-	storeSpec := "[" + s.transport.store.GraphDriverName() + "@" + s.transport.store.GraphRoot() + "]"
+	optionsList := ""
+	options := s.transport.store.GraphOptions()
+	if len(options) > 0 {
+		optionsList = ":" + strings.Join(options, ",")
+	}
+	storeSpec := "[" + s.transport.store.GraphDriverName() + "@" + s.transport.store.GraphRoot() + "+" + s.transport.store.RunRoot() + optionsList + "]"
 	if s.name == nil {
 		return storeSpec + "@" + s.id
 	}
@@ -94,7 +101,14 @@ func (s storageReference) StringWithinTransport() string {
 }
 
 func (s storageReference) PolicyConfigurationIdentity() string {
-	return s.StringWithinTransport()
+	storeSpec := "[" + s.transport.store.GraphDriverName() + "@" + s.transport.store.GraphRoot() + "]"
+	if s.name == nil {
+		return storeSpec + "@" + s.id
+	}
+	if s.id == "" {
+		return storeSpec + s.reference
+	}
+	return storeSpec + s.reference + "@" + s.id
 }
 
 // Also accept policy that's tied to the combination of the graph root and

vendor/github.com/containers/image/storage/storage_transport.go

@@ -11,6 +11,7 @@ import (
 	"github.com/containers/image/transports"
 	"github.com/containers/image/types"
 	"github.com/containers/storage"
+	"github.com/containers/storage/pkg/idtools"
 	"github.com/opencontainers/go-digest"
 	ddigest "github.com/opencontainers/go-digest"
 )
@@ -46,10 +47,20 @@ type StoreTransport interface {
 	// ParseStoreReference parses a reference, overriding any store
 	// specification that it may contain.
 	ParseStoreReference(store storage.Store, reference string) (*storageReference, error)
+	// SetDefaultUIDMap sets the default UID map to use when opening stores.
+	SetDefaultUIDMap(idmap []idtools.IDMap)
+	// SetDefaultGIDMap sets the default GID map to use when opening stores.
+	SetDefaultGIDMap(idmap []idtools.IDMap)
+	// DefaultUIDMap returns the default UID map used when opening stores.
+	DefaultUIDMap() []idtools.IDMap
+	// DefaultGIDMap returns the default GID map used when opening stores.
+	DefaultGIDMap() []idtools.IDMap
 }
 
 type storageTransport struct {
-	store storage.Store
+	store         storage.Store
+	defaultUIDMap []idtools.IDMap
+	defaultGIDMap []idtools.IDMap
 }
 
 func (s *storageTransport) Name() string {
@@ -66,6 +77,26 @@ func (s *storageTransport) SetStore(store storage.Store) {
 	s.store = store
 }
 
+// SetDefaultUIDMap sets the default UID map to use when opening stores.
+func (s *storageTransport) SetDefaultUIDMap(idmap []idtools.IDMap) {
+	s.defaultUIDMap = idmap
+}
+
+// SetDefaultGIDMap sets the default GID map to use when opening stores.
+func (s *storageTransport) SetDefaultGIDMap(idmap []idtools.IDMap) {
+	s.defaultGIDMap = idmap
+}
+
+// DefaultUIDMap returns the default UID map used when opening stores.
+func (s *storageTransport) DefaultUIDMap() []idtools.IDMap {
+	return s.defaultUIDMap
+}
+
+// DefaultGIDMap returns the default GID map used when opening stores.
+func (s *storageTransport) DefaultGIDMap() []idtools.IDMap {
+	return s.defaultGIDMap
+}
+
 // ParseStoreReference takes a name or an ID, tries to figure out which it is
 // relative to the given store, and returns it in a reference object.
 func (s storageTransport) ParseStoreReference(store storage.Store, ref string) (*storageReference, error) {
@@ -110,7 +141,12 @@ func (s storageTransport) ParseStoreReference(store storage.Store, ref string) (
 		// recognize.
 		return nil, ErrInvalidReference
 	}
-	storeSpec := "[" + store.GraphDriverName() + "@" + store.GraphRoot() + "]"
+	optionsList := ""
+	options := store.GraphOptions()
+	if len(options) > 0 {
+		optionsList = ":" + strings.Join(options, ",")
+	}
+	storeSpec := "[" + store.GraphDriverName() + "@" + store.GraphRoot() + "+" + store.RunRoot() + optionsList + "]"
 	id := ""
 	if sum.Validate() == nil {
 		id = sum.Hex()
@@ -127,14 +163,17 @@ func (s storageTransport) ParseStoreReference(store storage.Store, ref string) (
 	} else {
 		logrus.Debugf("parsed reference into %q", storeSpec+refname+"@"+id)
 	}
-	return newReference(storageTransport{store: store}, refname, id, name), nil
+	return newReference(storageTransport{store: store, defaultUIDMap: s.defaultUIDMap, defaultGIDMap: s.defaultGIDMap}, refname, id, name), nil
 }
 
 func (s *storageTransport) GetStore() (storage.Store, error) {
 	// Return the transport's previously-set store.  If we don't have one
 	// of those, initialize one now.
 	if s.store == nil {
-		store, err := storage.GetStore(storage.DefaultStoreOptions)
+		options := storage.DefaultStoreOptions
+		options.UIDMap = s.defaultUIDMap
+		options.GIDMap = s.defaultGIDMap
+		store, err := storage.GetStore(options)
 		if err != nil {
 			return nil, err
 		}
@@ -145,15 +184,11 @@ func (s *storageTransport) GetStore() (storage.Store, error) {
 
 // ParseReference takes a name and/or an ID ("_name_"/"@_id_"/"_name_@_id_"),
 // possibly prefixed with a store specifier in the form "[_graphroot_]" or
-// "[_driver_@_graphroot_]", tries to figure out which it is, and returns it in
+// "[_driver_@_graphroot_]" or "[_driver_@_graphroot_+_runroot_]" or
-// a reference object.  If the _graphroot_ is a location other than the default,
+// "[_driver_@_graphroot_:_options_]" or "[_driver_@_graphroot_+_runroot_:_options_]",
-// it needs to have been previously opened using storage.GetStore(), so that it
+// tries to figure out which it is, and returns it in a reference object.
-// can figure out which run root goes with the graph root.
 func (s *storageTransport) ParseReference(reference string) (types.ImageReference, error) {
-	store, err := s.GetStore()
+	var store storage.Store
-	if err != nil {
-		return nil, err
-	}
 	// Check if there's a store location prefix.  If there is, then it
 	// needs to match a store that was previously initialized using
 	// storage.GetStore(), or be enough to let the storage library fill out
@@ -165,37 +200,65 @@ func (s *storageTransport) ParseReference(reference string) (types.ImageReferenc
 		}
 		storeSpec := reference[1:closeIndex]
 		reference = reference[closeIndex+1:]
-		storeInfo := strings.SplitN(storeSpec, "@", 2)
+		// Peel off a "driver@" from the start.
-		if len(storeInfo) == 1 && storeInfo[0] != "" {
+		driverInfo := ""
-			// One component: the graph root.
+		driverSplit := strings.SplitN(storeSpec, "@", 2)
-			if !filepath.IsAbs(storeInfo[0]) {
+		if len(driverSplit) != 2 {
-				return nil, ErrPathNotAbsolute
+			if storeSpec == "" {
+				return nil, ErrInvalidReference
 			}
-			store2, err := storage.GetStore(storage.StoreOptions{
-				GraphRoot: storeInfo[0],
-			})
-			if err != nil {
-				return nil, err
-			}
-			store = store2
-		} else if len(storeInfo) == 2 && storeInfo[0] != "" && storeInfo[1] != "" {
-			// Two components: the driver type and the graph root.
-			if !filepath.IsAbs(storeInfo[1]) {
-				return nil, ErrPathNotAbsolute
-			}
-			store2, err := storage.GetStore(storage.StoreOptions{
-				GraphDriverName: storeInfo[0],
-				GraphRoot:       storeInfo[1],
-			})
-			if err != nil {
-				return nil, err
-			}
-			store = store2
 		} else {
-			// Anything else: store specified in a form we don't
+			driverInfo = driverSplit[0]
-			// recognize.
+			if driverInfo == "" {
-			return nil, ErrInvalidReference
+				return nil, ErrInvalidReference
+			}
+			storeSpec = driverSplit[1]
+			if storeSpec == "" {
+				return nil, ErrInvalidReference
+			}
 		}
+		// Peel off a ":options" from the end.
+		var options []string
+		optionsSplit := strings.SplitN(storeSpec, ":", 2)
+		if len(optionsSplit) == 2 {
+			options = strings.Split(optionsSplit[1], ",")
+			storeSpec = optionsSplit[0]
+		}
+		// Peel off a "+runroot" from the new end.
+		runRootInfo := ""
+		runRootSplit := strings.SplitN(storeSpec, "+", 2)
+		if len(runRootSplit) == 2 {
+			runRootInfo = runRootSplit[1]
+			storeSpec = runRootSplit[0]
+		}
+		// The rest is our graph root.
+		rootInfo := storeSpec
+		// Check that any paths are absolute paths.
+		if rootInfo != "" && !filepath.IsAbs(rootInfo) {
+			return nil, ErrPathNotAbsolute
+		}
+		if runRootInfo != "" && !filepath.IsAbs(runRootInfo) {
+			return nil, ErrPathNotAbsolute
+		}
+		store2, err := storage.GetStore(storage.StoreOptions{
+			GraphDriverName:    driverInfo,
+			GraphRoot:          rootInfo,
+			RunRoot:            runRootInfo,
+			GraphDriverOptions: options,
+			UIDMap:             s.defaultUIDMap,
+			GIDMap:             s.defaultGIDMap,
+		})
+		if err != nil {
+			return nil, err
+		}
+		store = store2
+	} else {
+		// We didn't have a store spec, so use the default.
+		store2, err := s.GetStore()
+		if err != nil {
+			return nil, err
+		}
+		store = store2
 	}
 	return s.ParseStoreReference(store, reference)
 }
@@ -250,7 +313,7 @@ func (s storageTransport) ValidatePolicyConfigurationScope(scope string) error {
 			return ErrPathNotAbsolute
 		}
 	} else {
-		// Anything else: store specified in a form we don't
+		// Anything else: scope specified in a form we don't
 		// recognize.
 		return ErrInvalidReference
 	}

vendor/github.com/containers/image/transports/alltransports/alltransports.go

@@ -12,7 +12,7 @@ import (
 	_ "github.com/containers/image/docker/daemon"
 	_ "github.com/containers/image/oci/layout"
 	_ "github.com/containers/image/openshift"
-	_ "github.com/containers/image/ostree"
+	// The ostree transport is registered by ostree*.go
 	_ "github.com/containers/image/storage"
 	"github.com/containers/image/transports"
 	"github.com/containers/image/types"

vendor/github.com/containers/image/transports/transports.go

@@ -2,6 +2,7 @@ package transports
 
 import (
 	"fmt"
+	"sort"
 	"sync"
 
 	"github.com/containers/image/types"
@@ -69,3 +70,15 @@ func Register(t types.ImageTransport) {
 func ImageName(ref types.ImageReference) string {
 	return ref.Transport().Name() + ":" + ref.StringWithinTransport()
 }
+
+// ListNames returns a list of transport names
+func ListNames() []string {
+	kt.mu.Lock()
+	defer kt.mu.Unlock()
+	var names []string
+	for _, transport := range kt.transports {
+		names = append(names, transport.Name())
+	}
+	sort.Strings(names)
+	return names
+}

vendor/github.com/containers/image/types/types.go

@@ -148,11 +148,11 @@ type ImageDestination interface {
 	SupportsSignatures() error
 	// ShouldCompressLayers returns true iff it is desirable to compress layer blobs written to this destination.
 	ShouldCompressLayers() bool
-
 	// AcceptsForeignLayerURLs returns false iff foreign layers in manifest should be actually
 	// uploaded to the image destination, true otherwise.
 	AcceptsForeignLayerURLs() bool
-
+	// MustMatchRuntimeOS returns true iff the destination can store only images targeted for the current runtime OS. False otherwise.
+	MustMatchRuntimeOS() bool
 	// PutBlob writes contents of stream and returns data representing the result (with all data filled in).
 	// inputInfo.Digest can be optionally provided if known; it is not mandatory for the implementation to verify it.
 	// inputInfo.Size is the expected length of stream, if known.

vendor/github.com/containers/image/vendor.conf

@@ -1,5 +1,5 @@
 github.com/Sirupsen/logrus 7f4b1adc791766938c29457bed0703fb9134421a
-github.com/containers/storage 989b1c1d85f5dfe2076c67b54289cc13dc836c8c
+github.com/containers/storage 105f7c77aef0c797429e41552743bf5b03b63263
 github.com/davecgh/go-spew 346938d642f2ec3594ed81d874461961cd0faa76
 github.com/docker/distribution df5327f76fb6468b84a87771e361762b8be23fdb
 github.com/docker/docker 75843d36aa5c3eaade50da005f9e0ff2602f3d5e
@@ -15,7 +15,7 @@ github.com/mattn/go-shellwords 005a0944d84452842197c2108bd9168ced206f78
 github.com/mistifyio/go-zfs c0224de804d438efd11ea6e52ada8014537d6062
 github.com/mtrmac/gpgme b2432428689ca58c2b8e8dea9449d3295cf96fc9
 github.com/opencontainers/go-digest aa2ec055abd10d26d539eb630a92241b781ce4bc
-github.com/opencontainers/image-spec v1.0.0-rc6
+github.com/opencontainers/image-spec v1.0.0
 github.com/opencontainers/runc 6b1d0e76f239ffb435445e5ae316d2676c07c6e3
 github.com/pborman/uuid 1b00554d822231195d1babd97ff4a781231955c9
 github.com/pkg/errors 248dadf4e9068a0b3e79f02ed0a610d935de5302
@@ -34,4 +34,4 @@ github.com/xeipuuv/gojsonpointer master
 github.com/tchap/go-patricia v2.2.6
 github.com/opencontainers/selinux ba1aefe8057f1d0cfb8e88d0ec1dc85925ef987d
 github.com/BurntSushi/toml b26d9c308763d68093482582cea63d69be07a0f0
-github.com/ostreedev/ostree-go 61532f383f1f48e5c27080b0b9c8b022c3706a97
+github.com/ostreedev/ostree-go aeb02c6b6aa2889db3ef62f7855650755befd460

vendor/github.com/containers/storage/README.md

@@ -1,6 +1,6 @@
 `storage` is a Go library which aims to provide methods for storing filesystem
-layers, container images, and containers.  An `oci-storage` CLI wrapper is also
+layers, container images, and containers.  A `containers-storage` CLI wrapper
-included for manual and scripting use.
+is also included for manual and scripting use.
 
 To build the CLI wrapper, use 'make build-binary'.
 

vendor/github.com/containers/storage/containers.go

@@ -50,6 +50,12 @@ type Container struct {
 	// that has been stored, if they're known.
 	BigDataSizes map[string]int64 `json:"big-data-sizes,omitempty"`
 
+	// Created is the datestamp for when this container was created.  Older
+	// versions of the library did not track this information, so callers
+	// will likely want to use the IsZero() method to verify that a value
+	// is set before using it.
+	Created time.Time `json:"created,omitempty"`
+
 	Flags map[string]interface{} `json:"flags,omitempty"`
 }
 
@@ -93,7 +99,7 @@ type ContainerStore interface {
 type containerStore struct {
 	lockfile   Locker
 	dir        string
-	containers []Container
+	containers []*Container
 	idindex    *truncindex.TruncIndex
 	byid       map[string]*Container
 	bylayer    map[string]*Container
@@ -101,7 +107,11 @@ type containerStore struct {
 }
 
 func (r *containerStore) Containers() ([]Container, error) {
-	return r.containers, nil
+	containers := make([]Container, len(r.containers))
+	for i := range r.containers {
+		containers[i] = *(r.containers[i])
+	}
+	return containers, nil
 }
 
 func (r *containerStore) containerspath() string {
@@ -123,7 +133,7 @@ func (r *containerStore) Load() error {
 	if err != nil && !os.IsNotExist(err) {
 		return err
 	}
-	containers := []Container{}
+	containers := []*Container{}
 	layers := make(map[string]*Container)
 	idlist := []string{}
 	ids := make(map[string]*Container)
@@ -131,14 +141,14 @@ func (r *containerStore) Load() error {
 	if err = json.Unmarshal(data, &containers); len(data) == 0 || err == nil {
 		for n, container := range containers {
 			idlist = append(idlist, container.ID)
-			ids[container.ID] = &containers[n]
+			ids[container.ID] = containers[n]
-			layers[container.LayerID] = &containers[n]
+			layers[container.LayerID] = containers[n]
 			for _, name := range container.Names {
 				if conflict, ok := names[name]; ok {
 					r.removeName(conflict, name)
 					needSave = true
 				}
-				names[name] = &containers[n]
+				names[name] = containers[n]
 			}
 		}
 	}
@@ -148,7 +158,6 @@ func (r *containerStore) Load() error {
 	r.bylayer = layers
 	r.byname = names
 	if needSave {
-		r.Touch()
 		return r.Save()
 	}
 	return nil
@@ -163,6 +172,7 @@ func (r *containerStore) Save() error {
 	if err != nil {
 		return err
 	}
+	defer r.Touch()
 	return ioutils.AtomicWriteFile(rpath, jdata, 0600)
 }
 
@@ -179,7 +189,7 @@ func newContainerStore(dir string) (ContainerStore, error) {
 	cstore := containerStore{
 		lockfile:   lockfile,
 		dir:        dir,
-		containers: []Container{},
+		containers: []*Container{},
 		byid:       make(map[string]*Container),
 		bylayer:    make(map[string]*Container),
 		byname:     make(map[string]*Container),
@@ -241,7 +251,7 @@ func (r *containerStore) Create(id string, names []string, image, layer, metadat
 		}
 	}
 	if err == nil {
-		newContainer := Container{
+		container = &Container{
 			ID:           id,
 			Names:        names,
 			ImageID:      image,
@@ -249,10 +259,10 @@ func (r *containerStore) Create(id string, names []string, image, layer, metadat
 			Metadata:     metadata,
 			BigDataNames: []string{},
 			BigDataSizes: make(map[string]int64),
+			Created:      time.Now().UTC(),
 			Flags:        make(map[string]interface{}),
 		}
-		r.containers = append(r.containers, newContainer)
+		r.containers = append(r.containers, container)
-		container = &r.containers[len(r.containers)-1]
 		r.byid[id] = container
 		r.idindex.Add(id)
 		r.bylayer[layer] = container
@@ -306,10 +316,11 @@ func (r *containerStore) Delete(id string) error {
 		return ErrContainerUnknown
 	}
 	id = container.ID
-	newContainers := []Container{}
+	toDeleteIndex := -1
-	for _, candidate := range r.containers {
+	for i, candidate := range r.containers {
-		if candidate.ID != id {
+		if candidate.ID == id {
-			newContainers = append(newContainers, candidate)
+			toDeleteIndex = i
+			break
 		}
 	}
 	delete(r.byid, id)
@@ -318,7 +329,14 @@ func (r *containerStore) Delete(id string) error {
 	for _, name := range container.Names {
 		delete(r.byname, name)
 	}
-	r.containers = newContainers
+	if toDeleteIndex != -1 {
+		// delete the container at toDeleteIndex
+		if toDeleteIndex == len(r.containers)-1 {
+			r.containers = r.containers[:len(r.containers)-1]
+		} else {
+			r.containers = append(r.containers[:toDeleteIndex], r.containers[toDeleteIndex+1:]...)
+		}
+	}
 	if err := r.Save(); err != nil {
 		return err
 	}
@@ -437,6 +455,10 @@ func (r *containerStore) Modified() (bool, error) {
 	return r.lockfile.Modified()
 }
 
+func (r *containerStore) IsReadWrite() bool {
+	return r.lockfile.IsReadWrite()
+}
+
 func (r *containerStore) TouchedSince(when time.Time) bool {
 	return r.lockfile.TouchedSince(when)
 }

vendor/github.com/containers/storage/drivers/aufs/aufs.go

@@ -47,6 +47,7 @@ import (
 
 	rsystem "github.com/opencontainers/runc/libcontainer/system"
 	"github.com/opencontainers/selinux/go-selinux/label"
+	"github.com/pkg/errors"
 )
 
 var (
@@ -81,7 +82,7 @@ func Init(root string, options []string, uidMaps, gidMaps []idtools.IDMap) (grap
 
 	// Try to load the aufs kernel module
 	if err := supportsAufs(); err != nil {
-		return nil, graphdriver.ErrNotSupported
+		return nil, errors.Wrap(graphdriver.ErrNotSupported, "kernel does not support aufs")
 	}
 
 	fsMagic, err := graphdriver.GetFSMagic(root)
@@ -95,7 +96,7 @@ func Init(root string, options []string, uidMaps, gidMaps []idtools.IDMap) (grap
 	switch fsMagic {
 	case graphdriver.FsMagicAufs, graphdriver.FsMagicBtrfs, graphdriver.FsMagicEcryptfs:
 		logrus.Errorf("AUFS is not supported over %s", backingFs)
-		return nil, graphdriver.ErrIncompatibleFS
+		return nil, errors.Wrapf(graphdriver.ErrIncompatibleFS, "AUFS is not supported over %q", backingFs)
 	}
 
 	paths := []string{
@@ -372,6 +373,12 @@ func (a *Driver) Diff(id, parent string) (archive.Archive, error) {
 	})
 }
 
+// AdditionalImageStores returns additional image stores supported by the driver
+func (a *Driver) AdditionalImageStores() []string {
+	var imageStores []string
+	return imageStores
+}
+
 type fileGetNilCloser struct {
 	storage.FileGetter
 }

vendor/github.com/containers/storage/drivers/aufs/mount_unsupported.go

@@ -2,7 +2,7 @@
 
 package aufs
 
-import "errors"
+import "github.com/pkg/errors"
 
 // MsRemount declared to specify a non-linux system mount.
 const MsRemount = 0

vendor/github.com/containers/storage/drivers/btrfs/btrfs.go

@@ -29,6 +29,7 @@ import (
 	"github.com/containers/storage/pkg/parsers"
 	"github.com/docker/go-units"
 	"github.com/opencontainers/selinux/go-selinux/label"
+	"github.com/pkg/errors"
 )
 
 func init() {
@@ -55,7 +56,7 @@ func Init(home string, options []string, uidMaps, gidMaps []idtools.IDMap) (grap
 	}
 
 	if fsMagic != graphdriver.FsMagicBtrfs {
-		return nil, graphdriver.ErrPrerequisites
+		return nil, errors.Wrapf(graphdriver.ErrPrerequisites, "%q is not on a btrfs filesystem", home)
 	}
 
 	rootUID, rootGID, err := idtools.GetRootUIDGID(uidMaps, gidMaps)
@@ -518,3 +519,9 @@ func (d *Driver) Exists(id string) bool {
 	_, err := os.Stat(dir)
 	return err == nil
 }
+
+// AdditionalImageStores returns additional image stores supported by the driver
+func (d *Driver) AdditionalImageStores() []string {
+	var imageStores []string
+	return imageStores
+}

vendor/github.com/containers/storage/drivers/devmapper/deviceset.go

@@ -5,7 +5,6 @@ package devmapper
 import (
 	"bufio"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -28,10 +27,10 @@ import (
 	"github.com/containers/storage/pkg/loopback"
 	"github.com/containers/storage/pkg/mount"
 	"github.com/containers/storage/pkg/parsers"
-	"github.com/containers/storage/storageversion"
 	"github.com/docker/go-units"
 
 	"github.com/opencontainers/selinux/go-selinux/label"
+	"github.com/pkg/errors"
 )
 
 var (
@@ -1475,7 +1474,7 @@ func determineDriverCapabilities(version string) error {
 	versionSplit := strings.Split(version, ".")
 	major, err := strconv.Atoi(versionSplit[0])
 	if err != nil {
-		return graphdriver.ErrNotSupported
+		return errors.Wrapf(graphdriver.ErrNotSupported, "unable to parse driver major version %q as a number", versionSplit[0])
 	}
 
 	if major > 4 {
@@ -1489,7 +1488,7 @@ func determineDriverCapabilities(version string) error {
 
 	minor, err := strconv.Atoi(versionSplit[1])
 	if err != nil {
-		return graphdriver.ErrNotSupported
+		return errors.Wrapf(graphdriver.ErrNotSupported, "unable to parse driver minor version %q as a number", versionSplit[1])
 	}
 
 	/*
@@ -1656,11 +1655,11 @@ func (devices *DeviceSet) initDevmapper(doInit bool) error {
 	version, err := devicemapper.GetDriverVersion()
 	if err != nil {
 		// Can't even get driver version, assume not supported
-		return graphdriver.ErrNotSupported
+		return errors.Wrap(graphdriver.ErrNotSupported, "unable to determine version of device mapper")
 	}
 
 	if err := determineDriverCapabilities(version); err != nil {
-		return graphdriver.ErrNotSupported
+		return errors.Wrap(graphdriver.ErrNotSupported, "unable to determine device mapper driver capabilities")
 	}
 
 	if err := devices.enableDeferredRemovalDeletion(); err != nil {
@@ -1668,17 +1667,17 @@ func (devices *DeviceSet) initDevmapper(doInit bool) error {
 	}
 
 	// https://github.com/docker/docker/issues/4036
-	if supported := devicemapper.UdevSetSyncSupport(true); !supported {
+	// if supported := devicemapper.UdevSetSyncSupport(true); !supported {
-		if storageversion.IAmStatic == "true" {
+	// 	if storageversion.IAmStatic == "true" {
-			logrus.Errorf("devmapper: Udev sync is not supported. This will lead to data loss and unexpected behavior. Install a dynamic binary to use devicemapper or select a different storage driver. For more information, see https://docs.docker.com/engine/reference/commandline/daemon/#daemon-storage-driver-option")
+	// 		logrus.Errorf("devmapper: Udev sync is not supported. This will lead to data loss and unexpected behavior. Install a dynamic binary to use devicemapper or select a different storage driver. For more information, see https://docs.docker.com/engine/reference/commandline/daemon/#daemon-storage-driver-option")
-		} else {
+	// 	} else {
-			logrus.Errorf("devmapper: Udev sync is not supported. This will lead to data loss and unexpected behavior. Install a more recent version of libdevmapper or select a different storage driver. For more information, see https://docs.docker.com/engine/reference/commandline/daemon/#daemon-storage-driver-option")
+	// 		logrus.Errorf("devmapper: Udev sync is not supported. This will lead to data loss and unexpected behavior. Install a more recent version of libdevmapper or select a different storage driver. For more information, see https://docs.docker.com/engine/reference/commandline/daemon/#daemon-storage-driver-option")
-		}
+	// 	}
-
+	//
-		if !devices.overrideUdevSyncCheck {
+	// 	if !devices.overrideUdevSyncCheck {
-			return graphdriver.ErrNotSupported
+	// 		return graphdriver.ErrNotSupported
-		}
+	// 	}
-	}
+	// }
 
 	//create the root dir of the devmapper driver ownership to match this
 	//daemon's remapped root uid/gid so containers can start properly
@@ -1734,6 +1733,15 @@ func (devices *DeviceSet) initDevmapper(doInit bool) error {
 			metadataFile *os.File
 		)
 
+		fsMagic, err := graphdriver.GetFSMagic(devices.loopbackDir())
+		if err != nil {
+			return err
+		}
+		switch fsMagic {
+		case graphdriver.FsMagicAufs:
+			return errors.Errorf("devmapper: Loopback devices can not be created on AUFS filesystems")
+		}
+
 		if devices.dataDevice == "" {
 			// Make sure the sparse images exist in <root>/devicemapper/data
 
@@ -1960,7 +1968,7 @@ func (devices *DeviceSet) deleteTransaction(info *devInfo, syncDelete bool) erro
 		// If syncDelete is true, we want to return error. If deferred
 		// deletion is not enabled, we return an error. If error is
 		// something other then EBUSY, return an error.
-		if syncDelete || !devices.deferredDelete || err != devicemapper.ErrBusy {
+		if syncDelete || !devices.deferredDelete || errors.Cause(err) != devicemapper.ErrBusy {
 			logrus.Debugf("devmapper: Error deleting device: %s", err)
 			return err
 		}
@@ -2115,7 +2123,7 @@ func (devices *DeviceSet) removeDevice(devname string) error {
 		if err == nil {
 			break
 		}
-		if err != devicemapper.ErrBusy {
+		if errors.Cause(err) != devicemapper.ErrBusy {
 			return err
 		}
 
@@ -2150,12 +2158,12 @@ func (devices *DeviceSet) cancelDeferredRemoval(info *devInfo) error {
 			break
 		}
 
-		if err == devicemapper.ErrEnxio {
+		if errors.Cause(err) == devicemapper.ErrEnxio {
 			// Device is probably already gone. Return success.
 			return nil
 		}
 
-		if err != devicemapper.ErrBusy {
+		if errors.Cause(err) != devicemapper.ErrBusy {
 			return err
 		}
 

vendor/github.com/containers/storage/drivers/devmapper/driver.go

@@ -224,3 +224,9 @@ func (d *Driver) Put(id string) error {
 func (d *Driver) Exists(id string) bool {
 	return d.DeviceSet.HasDevice(id)
 }
+
+// AdditionalImageStores returns additional image stores supported by the driver
+func (d *Driver) AdditionalImageStores() []string {
+	var imageStores []string
+	return imageStores
+}

vendor/github.com/containers/storage/drivers/driver.go

@@ -1,13 +1,13 @@
 package graphdriver
 
 import (
-	"errors"
 	"fmt"
 	"os"
 	"path/filepath"
 	"strings"
 
 	"github.com/Sirupsen/logrus"
+	"github.com/pkg/errors"
 	"github.com/vbatts/tar-split/tar/storage"
 
 	"github.com/containers/storage/pkg/archive"
@@ -74,6 +74,8 @@ type ProtoDriver interface {
 	// held by the driver, e.g., unmounting all layered filesystems
 	// known to this driver.
 	Cleanup() error
+	// AdditionalImageStores returns additional image stores supported by the driver
+	AdditionalImageStores() []string
 }
 
 // Driver is the interface for layered/snapshot file system drivers.
@@ -142,7 +144,7 @@ func GetDriver(name, home string, options []string, uidMaps, gidMaps []idtools.I
 		return pluginDriver, nil
 	}
 	logrus.Errorf("Failed to GetDriver graph %s %s", name, home)
-	return nil, ErrNotSupported
+	return nil, errors.Wrapf(ErrNotSupported, "failed to GetDriver graph %s %s", name, home)
 }
 
 // getBuiltinDriver initializes and returns the registered driver, but does not try to load from plugins
@@ -151,7 +153,7 @@ func getBuiltinDriver(name, home string, options []string, uidMaps, gidMaps []id
 		return initFunc(filepath.Join(home, name), options, uidMaps, gidMaps)
 	}
 	logrus.Errorf("Failed to built-in GetDriver graph %s %s", name, home)
-	return nil, ErrNotSupported
+	return nil, errors.Wrapf(ErrNotSupported, "failed to built-in GetDriver graph %s %s", name, home)
 }
 
 // New creates the driver and initializes it at the specified root.
@@ -226,7 +228,8 @@ func New(root string, name string, options []string, uidMaps, gidMaps []idtools.
 // isDriverNotSupported returns true if the error initializing
 // the graph driver is a non-supported error.
 func isDriverNotSupported(err error) bool {
-	return err == ErrNotSupported || err == ErrPrerequisites || err == ErrIncompatibleFS
+	cause := errors.Cause(err)
+	return cause == ErrNotSupported || cause == ErrPrerequisites || cause == ErrIncompatibleFS
 }
 
 // scanPriorDrivers returns an un-ordered scan of directories of prior storage drivers

vendor/github.com/containers/storage/drivers/driver_linux.go

@@ -53,7 +53,7 @@ const (
 var (
 	// Slice of drivers that should be used in an order
 	priority = []string{
-		"overlay2",
+		"overlay",
 		"devicemapper",
 		"aufs",
 		"btrfs",

vendor/github.com/containers/storage/drivers/driver_solaris.go

@@ -20,6 +20,7 @@ import (
 	"unsafe"
 
 	log "github.com/Sirupsen/logrus"
+	"github.com/pkg/errors"
 )
 
 const (
@@ -56,7 +57,7 @@ func Mounted(fsType FsMagic, mountPath string) (bool, error) {
 		(buf.f_basetype[3] != 0) {
 		log.Debugf("[zfs] no zfs dataset found for rootdir '%s'", mountPath)
 		C.free(unsafe.Pointer(buf))
-		return false, ErrPrerequisites
+		return false, errors.Wrapf(graphdriver.ErrPrerequisites, "no zfs dataset found for rootdir '%s'", mountPath)
 	}
 
 	C.free(unsafe.Pointer(buf))

vendor/github.com/containers/storage/drivers/overlay/overlay.go

@@ -4,12 +4,12 @@ package overlay
 
 import (
 	"bufio"
-	"errors"
 	"fmt"
 	"io/ioutil"
 	"os"
 	"os/exec"
 	"path"
+	"path/filepath"
 	"strconv"
 	"strings"
 	"syscall"
@@ -26,6 +26,7 @@ import (
 	"github.com/containers/storage/pkg/parsers/kernel"
 
 	"github.com/opencontainers/selinux/go-selinux/label"
+	"github.com/pkg/errors"
 )
 
 var (
@@ -82,6 +83,7 @@ type Driver struct {
 	uidMaps []idtools.IDMap
 	gidMaps []idtools.IDMap
 	ctr     *graphdriver.RefCounter
+	opts    *overlayOptions
 }
 
 var backingFs = "<unknown>"
@@ -100,7 +102,7 @@ func InitWithName(name, home string, options []string, uidMaps, gidMaps []idtool
 	}
 
 	if err := supportsOverlay(); err != nil {
-		return nil, graphdriver.ErrNotSupported
+		return nil, errors.Wrap(graphdriver.ErrNotSupported, "kernel does not support overlay fs")
 	}
 
 	// require kernel 4.0.0 to ensure multiple lower dirs are supported
@@ -110,7 +112,7 @@ func InitWithName(name, home string, options []string, uidMaps, gidMaps []idtool
 	}
 	if kernel.CompareKernelVersion(*v, kernel.VersionInfo{Kernel: 4, Major: 0, Minor: 0}) < 0 {
 		if !opts.overrideKernelCheck {
-			return nil, graphdriver.ErrNotSupported
+			return nil, errors.Wrap(graphdriver.ErrNotSupported, "kernel too old to provide multiple lowers feature for overlay")
 		}
 		logrus.Warnf("Using pre-4.0.0 kernel for overlay, mount failures may require kernel update")
 	}
@@ -127,7 +129,7 @@ func InitWithName(name, home string, options []string, uidMaps, gidMaps []idtool
 	switch fsMagic {
 	case graphdriver.FsMagicBtrfs, graphdriver.FsMagicAufs, graphdriver.FsMagicZfs, graphdriver.FsMagicOverlay, graphdriver.FsMagicEcryptfs:
 		logrus.Errorf("'overlay' is not supported over %s", backingFs)
-		return nil, graphdriver.ErrIncompatibleFS
+		return nil, errors.Wrapf(graphdriver.ErrIncompatibleFS, "'overlay' is not supported over %s", backingFs)
 	}
 
 	rootUID, rootGID, err := idtools.GetRootUIDGID(uidMaps, gidMaps)
@@ -149,6 +151,7 @@ func InitWithName(name, home string, options []string, uidMaps, gidMaps []idtool
 		uidMaps: uidMaps,
 		gidMaps: gidMaps,
 		ctr:     graphdriver.NewRefCounter(graphdriver.NewFsChecker(graphdriver.FsMagicOverlay)),
+		opts:    opts,
 	}
 
 	return d, nil
@@ -170,6 +173,7 @@ func InitAsOverlay2(home string, options []string, uidMaps, gidMaps []idtools.ID
 
 type overlayOptions struct {
 	overrideKernelCheck bool
+	imageStores         []string
 }
 
 func parseOptions(options []string) (*overlayOptions, error) {
@@ -186,6 +190,22 @@ func parseOptions(options []string) (*overlayOptions, error) {
 			if err != nil {
 				return nil, err
 			}
+		case "overlay.imagestore":
+			// Additional read only image stores to use for lower paths
+			for _, store := range strings.Split(val, ",") {
+				store = filepath.Clean(store)
+				if !filepath.IsAbs(store) {
+					return nil, fmt.Errorf("overlay: image path %q is not absolute.  Can not be relative", store)
+				}
+				st, err := os.Stat(store)
+				if err != nil {
+					return nil, fmt.Errorf("overlay: Can't stat imageStore dir %s: %v", store, err)
+				}
+				if !st.IsDir() {
+					return nil, fmt.Errorf("overlay: image path %q must be a directory", store)
+				}
+				o.imageStores = append(o.imageStores, store)
+			}
 		default:
 			return nil, fmt.Errorf("overlay: Unknown option %s", key)
 		}
@@ -211,7 +231,7 @@ func supportsOverlay() error {
 		}
 	}
 	logrus.Error("'overlay' not found as a supported filesystem on this host. Please ensure kernel is new enough and has overlay support loaded.")
-	return graphdriver.ErrNotSupported
+	return errors.Wrap(graphdriver.ErrNotSupported, "'overlay' not found as a supported filesystem on this host. Please ensure kernel is new enough and has overlay support loaded.")
 }
 
 func (d *Driver) String() string {
@@ -357,8 +377,18 @@ func (d *Driver) getLower(parent string) (string, error) {
 	return strings.Join(lowers, ":"), nil
 }
 
-func (d *Driver) dir(id string) string {
+func (d *Driver) dir(val string) string {
-	return path.Join(d.home, id)
+	newpath := path.Join(d.home, val)
+	if _, err := os.Stat(newpath); err != nil {
+		for _, p := range d.AdditionalImageStores() {
+			l := path.Join(p, d.name, val)
+			_, err = os.Stat(l)
+			if err == nil {
+				return l
+			}
+		}
+	}
+	return newpath
 }
 
 func (d *Driver) getLowerDirs(id string) ([]string, error) {
@@ -366,11 +396,12 @@ func (d *Driver) getLowerDirs(id string) ([]string, error) {
 	lowers, err := ioutil.ReadFile(path.Join(d.dir(id), lowerFile))
 	if err == nil {
 		for _, s := range strings.Split(string(lowers), ":") {
-			lp, err := os.Readlink(path.Join(d.home, s))
+			lower := d.dir(s)
+			lp, err := os.Readlink(lower)
 			if err != nil {
 				return nil, err
 			}
-			lowersArray = append(lowersArray, path.Clean(path.Join(d.home, "link", lp)))
+			lowersArray = append(lowersArray, path.Clean(d.dir(path.Join("link", lp))))
 		}
 	} else if !os.IsNotExist(err) {
 		return nil, err
@@ -411,6 +442,31 @@ func (d *Driver) Get(id string, mountLabel string) (s string, err error) {
 		return "", err
 	}
 
+	newlowers := ""
+	for _, l := range strings.Split(string(lowers), ":") {
+		lower := ""
+		newpath := path.Join(d.home, l)
+		if _, err := os.Stat(newpath); err != nil {
+			for _, p := range d.AdditionalImageStores() {
+				lower = path.Join(p, d.name, l)
+				if _, err2 := os.Stat(lower); err2 == nil {
+					break
+				}
+				lower = ""
+			}
+			if lower == "" {
+				return "", fmt.Errorf("Can't stat lower layer %q: %v", newpath, err)
+			}
+		} else {
+			lower = l
+		}
+		if newlowers == "" {
+			newlowers = lower
+		} else {
+			newlowers = newlowers + ":" + lower
+		}
+	}
+
 	mergedDir := path.Join(dir, "merged")
 	if count := d.ctr.Increment(mergedDir); count > 1 {
 		return mergedDir, nil
@@ -424,7 +480,7 @@ func (d *Driver) Get(id string, mountLabel string) (s string, err error) {
 	}()
 
 	workDir := path.Join(dir, "work")
-	opts := fmt.Sprintf("lowerdir=%s,upperdir=%s,workdir=%s", string(lowers), path.Join(id, "diff"), path.Join(id, "work"))
+	opts := fmt.Sprintf("lowerdir=%s,upperdir=%s,workdir=%s", newlowers, path.Join(id, "diff"), path.Join(id, "work"))
 	mountLabel = label.FormatMountLabel(opts, mountLabel)
 	if len(mountLabel) > syscall.Getpagesize() {
 		return "", fmt.Errorf("cannot mount layer, mount label too large %d", len(mountLabel))
@@ -527,3 +583,8 @@ func (d *Driver) Changes(id, parent string) ([]archive.Change, error) {
 
 	return archive.OverlayChanges(layers, diffPath)
 }
+
+// AdditionalImageStores returns additional image stores supported by the driver
+func (d *Driver) AdditionalImageStores() []string {
+	return d.opts.imageStores
+}

vendor/github.com/containers/storage/drivers/proxy.go

@@ -3,10 +3,10 @@
 package graphdriver
 
 import (
-	"errors"
 	"fmt"
 
 	"github.com/containers/storage/pkg/archive"
+	"github.com/pkg/errors"
 )
 
 type graphDriverProxy struct {

vendor/github.com/containers/storage/drivers/vfs/driver.go

@@ -143,3 +143,9 @@ func (d *Driver) Exists(id string) bool {
 	_, err := os.Stat(d.dir(id))
 	return err == nil
 }
+
+// AdditionalImageStores returns additional image stores supported by the driver
+func (d *Driver) AdditionalImageStores() []string {
+	var imageStores []string
+	return imageStores
+}

vendor/github.com/containers/storage/drivers/zfs/zfs.go

@@ -20,6 +20,7 @@ import (
 	"github.com/containers/storage/pkg/parsers"
 	zfs "github.com/mistifyio/go-zfs"
 	"github.com/opencontainers/selinux/go-selinux/label"
+	"github.com/pkg/errors"
 )
 
 type zfsOptions struct {
@@ -47,13 +48,13 @@ func Init(base string, opt []string, uidMaps, gidMaps []idtools.IDMap) (graphdri
 
 	if _, err := exec.LookPath("zfs"); err != nil {
 		logrus.Debugf("[zfs] zfs command is not available: %v", err)
-		return nil, graphdriver.ErrPrerequisites
+		return nil, errors.Wrap(graphdriver.ErrPrerequisites, "the 'zfs' command is not available")
 	}
 
 	file, err := os.OpenFile("/dev/zfs", os.O_RDWR, 600)
 	if err != nil {
 		logrus.Debugf("[zfs] cannot open /dev/zfs: %v", err)
-		return nil, graphdriver.ErrPrerequisites
+		return nil, errors.Wrapf(graphdriver.ErrPrerequisites, "could not open /dev/zfs: %v", err)
 	}
 	defer file.Close()
 
@@ -403,3 +404,9 @@ func (d *Driver) Exists(id string) bool {
 	defer d.Unlock()
 	return d.filesystemsCache[d.zfsPath(id)] == true
 }
+
+// AdditionalImageStores returns additional image stores supported by the driver
+func (d *Driver) AdditionalImageStores() []string {
+	var imageStores []string
+	return imageStores
+}

vendor/github.com/containers/storage/drivers/zfs/zfs_freebsd.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/Sirupsen/logrus"
 	"github.com/containers/storage/drivers"
+	"github.com/pkg/errors"
 )
 
 func checkRootdirFs(rootdir string) error {
@@ -18,7 +19,7 @@ func checkRootdirFs(rootdir string) error {
 	// on FreeBSD buf.Fstypename contains ['z', 'f', 's', 0 ... ]
 	if (buf.Fstypename[0] != 122) || (buf.Fstypename[1] != 102) || (buf.Fstypename[2] != 115) || (buf.Fstypename[3] != 0) {
 		logrus.Debugf("[zfs] no zfs dataset found for rootdir '%s'", rootdir)
-		return graphdriver.ErrPrerequisites
+		return errors.Wrapf(graphdriver.ErrPrerequisites, "no zfs dataset found for rootdir '%s'", rootdir)
 	}
 
 	return nil

vendor/github.com/containers/storage/drivers/zfs/zfs_linux.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/Sirupsen/logrus"
 	"github.com/containers/storage/drivers"
+	"github.com/pkg/errors"
 )
 
 func checkRootdirFs(rootdir string) error {
@@ -16,7 +17,7 @@ func checkRootdirFs(rootdir string) error {
 
 	if graphdriver.FsMagic(buf.Type) != graphdriver.FsMagicZfs {
 		logrus.Debugf("[zfs] no zfs dataset found for rootdir '%s'", rootdir)
-		return graphdriver.ErrPrerequisites
+		return errors.Wrapf(graphdriver.ErrPrerequisites, "no zfs dataset found for rootdir '%s'", rootdir)
 	}
 
 	return nil

vendor/github.com/containers/storage/drivers/zfs/zfs_solaris.go

@@ -22,6 +22,7 @@ import (
 
 	log "github.com/Sirupsen/logrus"
 	"github.com/containers/storage/drivers"
+	"github.com/pkg/errors"
 )
 
 func checkRootdirFs(rootdir string) error {
@@ -34,7 +35,7 @@ func checkRootdirFs(rootdir string) error {
 		(buf.f_basetype[3] != 0) {
 		log.Debugf("[zfs] no zfs dataset found for rootdir '%s'", rootdir)
 		C.free(unsafe.Pointer(buf))
-		return graphdriver.ErrPrerequisites
+		return errors.Wrapf(graphdriver.ErrPrerequisites, "no zfs dataset found for rootdir '%s'", rootdir)
 	}
 
 	C.free(unsafe.Pointer(buf))

vendor/github.com/containers/storage/images.go

@@ -2,7 +2,6 @@ package storage
 
 import (
 	"encoding/json"
-	"errors"
 	"io/ioutil"
 	"os"
 	"path/filepath"
@@ -11,6 +10,7 @@ import (
 	"github.com/containers/storage/pkg/ioutils"
 	"github.com/containers/storage/pkg/stringid"
 	"github.com/containers/storage/pkg/truncindex"
+	"github.com/pkg/errors"
 )
 
 var (
@@ -46,24 +46,20 @@ type Image struct {
 	// that has been stored, if they're known.
 	BigDataSizes map[string]int64 `json:"big-data-sizes,omitempty"`
 
+	// Created is the datestamp for when this image was created.  Older
+	// versions of the library did not track this information, so callers
+	// will likely want to use the IsZero() method to verify that a value
+	// is set before using it.
+	Created time.Time `json:"created,omitempty"`
+
 	Flags map[string]interface{} `json:"flags,omitempty"`
 }
 
-// ImageStore provides bookkeeping for information about Images.
+// ROImageStore provides bookkeeping for information about Images.
-type ImageStore interface {
+type ROImageStore interface {
-	FileBasedStore
+	ROFileBasedStore
-	MetadataStore
+	ROMetadataStore
-	BigDataStore
+	ROBigDataStore
-	FlaggableStore
-
-	// Create creates an image that has a specified ID (or a random one) and
-	// optional names, using the specified layer as its topmost (hopefully
-	// read-only) layer.  That layer can be referenced by multiple images.
-	Create(id string, names []string, layer, metadata string) (*Image, error)
-
-	// SetNames replaces the list of names associated with an image with the
-	// supplied values.
-	SetNames(id string, names []string) error
 
 	// Exists checks if there is an image with the given ID or name.
 	Exists(id string) bool
@@ -71,12 +67,6 @@ type ImageStore interface {
 	// Get retrieves information about an image given an ID or name.
 	Get(id string) (*Image, error)
 
-	// Delete removes the record of the image.
-	Delete(id string) error
-
-	// Wipe removes records of all images.
-	Wipe() error
-
 	// Lookup attempts to translate a name to an ID.  Most methods do this
 	// implicitly.
 	Lookup(name string) (string, error)
@@ -85,17 +75,45 @@ type ImageStore interface {
 	Images() ([]Image, error)
 }
 
+// ImageStore provides bookkeeping for information about Images.
+type ImageStore interface {
+	ROImageStore
+	RWFileBasedStore
+	RWMetadataStore
+	RWBigDataStore
+	FlaggableStore
+
+	// Create creates an image that has a specified ID (or a random one) and
+	// optional names, using the specified layer as its topmost (hopefully
+	// read-only) layer.  That layer can be referenced by multiple images.
+	Create(id string, names []string, layer, metadata string, created time.Time) (*Image, error)
+
+	// SetNames replaces the list of names associated with an image with the
+	// supplied values.
+	SetNames(id string, names []string) error
+
+	// Delete removes the record of the image.
+	Delete(id string) error
+
+	// Wipe removes records of all images.
+	Wipe() error
+}
+
 type imageStore struct {
 	lockfile Locker
 	dir      string
-	images   []Image
+	images   []*Image
 	idindex  *truncindex.TruncIndex
 	byid     map[string]*Image
 	byname   map[string]*Image
 }
 
 func (r *imageStore) Images() ([]Image, error) {
-	return r.images, nil
+	images := make([]Image, len(r.images))
+	for i := range r.images {
+		images[i] = *(r.images[i])
+	}
+	return images, nil
 }
 
 func (r *imageStore) imagespath() string {
@@ -111,41 +129,46 @@ func (r *imageStore) datapath(id, key string) string {
 }
 
 func (r *imageStore) Load() error {
-	needSave := false
+	shouldSave := false
 	rpath := r.imagespath()
 	data, err := ioutil.ReadFile(rpath)
 	if err != nil && !os.IsNotExist(err) {
 		return err
 	}
-	images := []Image{}
+	images := []*Image{}
 	idlist := []string{}
 	ids := make(map[string]*Image)
 	names := make(map[string]*Image)
 	if err = json.Unmarshal(data, &images); len(data) == 0 || err == nil {
 		for n, image := range images {
-			ids[image.ID] = &images[n]
+			ids[image.ID] = images[n]
 			idlist = append(idlist, image.ID)
 			for _, name := range image.Names {
 				if conflict, ok := names[name]; ok {
 					r.removeName(conflict, name)
-					needSave = true
+					shouldSave = true
 				}
-				names[name] = &images[n]
+				names[name] = images[n]
 			}
 		}
 	}
+	if shouldSave && !r.IsReadWrite() {
+		return errors.New("image store assigns the same name to multiple images")
+	}
 	r.images = images
 	r.idindex = truncindex.NewTruncIndex(idlist)
 	r.byid = ids
 	r.byname = names
-	if needSave {
+	if shouldSave {
-		r.Touch()
 		return r.Save()
 	}
 	return nil
 }
 
 func (r *imageStore) Save() error {
+	if !r.IsReadWrite() {
+		return errors.Wrapf(ErrStoreIsReadOnly, "not allowed to modify the image store at %q", r.imagespath())
+	}
 	rpath := r.imagespath()
 	if err := os.MkdirAll(filepath.Dir(rpath), 0700); err != nil {
 		return err
@@ -154,6 +177,7 @@ func (r *imageStore) Save() error {
 	if err != nil {
 		return err
 	}
+	defer r.Touch()
 	return ioutils.AtomicWriteFile(rpath, jdata, 0600)
 }
 
@@ -170,7 +194,27 @@ func newImageStore(dir string) (ImageStore, error) {
 	istore := imageStore{
 		lockfile: lockfile,
 		dir:      dir,
-		images:   []Image{},
+		images:   []*Image{},
+		byid:     make(map[string]*Image),
+		byname:   make(map[string]*Image),
+	}
+	if err := istore.Load(); err != nil {
+		return nil, err
+	}
+	return &istore, nil
+}
+
+func newROImageStore(dir string) (ROImageStore, error) {
+	lockfile, err := GetROLockfile(filepath.Join(dir, "images.lock"))
+	if err != nil {
+		return nil, err
+	}
+	lockfile.Lock()
+	defer lockfile.Unlock()
+	istore := imageStore{
+		lockfile: lockfile,
+		dir:      dir,
+		images:   []*Image{},
 		byid:     make(map[string]*Image),
 		byname:   make(map[string]*Image),
 	}
@@ -193,6 +237,9 @@ func (r *imageStore) lookup(id string) (*Image, bool) {
 }
 
 func (r *imageStore) ClearFlag(id string, flag string) error {
+	if !r.IsReadWrite() {
+		return errors.Wrapf(ErrStoreIsReadOnly, "not allowed to clear flags on images at %q", r.imagespath())
+	}
 	image, ok := r.lookup(id)
 	if !ok {
 		return ErrImageUnknown
@@ -202,6 +249,9 @@ func (r *imageStore) ClearFlag(id string, flag string) error {
 }
 
 func (r *imageStore) SetFlag(id string, flag string, value interface{}) error {
+	if !r.IsReadWrite() {
+		return errors.Wrapf(ErrStoreIsReadOnly, "not allowed to set flags on images at %q", r.imagespath())
+	}
 	image, ok := r.lookup(id)
 	if !ok {
 		return ErrImageUnknown
@@ -210,7 +260,10 @@ func (r *imageStore) SetFlag(id string, flag string, value interface{}) error {
 	return r.Save()
 }
 
-func (r *imageStore) Create(id string, names []string, layer, metadata string) (image *Image, err error) {
+func (r *imageStore) Create(id string, names []string, layer, metadata string, created time.Time) (image *Image, err error) {
+	if !r.IsReadWrite() {
+		return nil, errors.Wrapf(ErrStoreIsReadOnly, "not allowed to create new images at %q", r.imagespath())
+	}
 	if id == "" {
 		id = stringid.GenerateRandomID()
 		_, idInUse := r.byid[id]
@@ -227,18 +280,21 @@ func (r *imageStore) Create(id string, names []string, layer, metadata string) (
 			return nil, ErrDuplicateName
 		}
 	}
+	if created.IsZero() {
+		created = time.Now().UTC()
+	}
 	if err == nil {
-		newImage := Image{
+		image = &Image{
 			ID:           id,
 			Names:        names,
 			TopLayer:     layer,
 			Metadata:     metadata,
 			BigDataNames: []string{},
 			BigDataSizes: make(map[string]int64),
+			Created:      created,
 			Flags:        make(map[string]interface{}),
 		}
-		r.images = append(r.images, newImage)
+		r.images = append(r.images, image)
-		image = &r.images[len(r.images)-1]
 		r.idindex.Add(id)
 		r.byid[id] = image
 		for _, name := range names {
@@ -257,6 +313,9 @@ func (r *imageStore) Metadata(id string) (string, error) {
 }
 
 func (r *imageStore) SetMetadata(id, metadata string) error {
+	if !r.IsReadWrite() {
+		return errors.Wrapf(ErrStoreIsReadOnly, "not allowed to modify image metadata at %q", r.imagespath())
+	}
 	if image, ok := r.lookup(id); ok {
 		image.Metadata = metadata
 		return r.Save()
@@ -269,6 +328,9 @@ func (r *imageStore) removeName(image *Image, name string) {
 }
 
 func (r *imageStore) SetNames(id string, names []string) error {
+	if !r.IsReadWrite() {
+		return errors.Wrapf(ErrStoreIsReadOnly, "not allowed to change image name assignments at %q", r.imagespath())
+	}
 	if image, ok := r.lookup(id); ok {
 		for _, name := range image.Names {
 			delete(r.byname, name)
@@ -286,15 +348,18 @@ func (r *imageStore) SetNames(id string, names []string) error {
 }
 
 func (r *imageStore) Delete(id string) error {
+	if !r.IsReadWrite() {
+		return errors.Wrapf(ErrStoreIsReadOnly, "not allowed to delete images at %q", r.imagespath())
+	}
 	image, ok := r.lookup(id)
 	if !ok {
 		return ErrImageUnknown
 	}
 	id = image.ID
-	newImages := []Image{}
+	toDeleteIndex := -1
-	for _, candidate := range r.images {
+	for i, candidate := range r.images {
-		if candidate.ID != id {
+		if candidate.ID == id {
-			newImages = append(newImages, candidate)
+			toDeleteIndex = i
 		}
 	}
 	delete(r.byid, id)
@@ -302,7 +367,14 @@ func (r *imageStore) Delete(id string) error {
 	for _, name := range image.Names {
 		delete(r.byname, name)
 	}
-	r.images = newImages
+	if toDeleteIndex != -1 {
+		// delete the image at toDeleteIndex
+		if toDeleteIndex == len(r.images)-1 {
+			r.images = r.images[:len(r.images)-1]
+		} else {
+			r.images = append(r.images[:toDeleteIndex], r.images[toDeleteIndex+1:]...)
+		}
+	}
 	if err := r.Save(); err != nil {
 		return err
 	}
@@ -359,6 +431,9 @@ func (r *imageStore) BigDataNames(id string) ([]string, error) {
 }
 
 func (r *imageStore) SetBigData(id, key string, data []byte) error {
+	if !r.IsReadWrite() {
+		return errors.Wrapf(ErrStoreIsReadOnly, "not allowed to save data items associated with images at %q", r.imagespath())
+	}
 	image, ok := r.lookup(id)
 	if !ok {
 		return ErrImageUnknown
@@ -393,6 +468,9 @@ func (r *imageStore) SetBigData(id, key string, data []byte) error {
 }
 
 func (r *imageStore) Wipe() error {
+	if !r.IsReadWrite() {
+		return errors.Wrapf(ErrStoreIsReadOnly, "not allowed to delete images at %q", r.imagespath())
+	}
 	ids := []string{}
 	for id := range r.byid {
 		ids = append(ids, id)
@@ -421,6 +499,10 @@ func (r *imageStore) Modified() (bool, error) {
 	return r.lockfile.Modified()
 }
 
+func (r *imageStore) IsReadWrite() bool {
+	return r.lockfile.IsReadWrite()
+}
+
 func (r *imageStore) TouchedSince(when time.Time) bool {
 	return r.lockfile.TouchedSince(when)
 }

vendor/github.com/containers/storage/layers.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"compress/gzip"
 	"encoding/json"
-	"errors"
 	"io"
 	"io/ioutil"
 	"os"
@@ -16,6 +15,8 @@ import (
 	"github.com/containers/storage/pkg/ioutils"
 	"github.com/containers/storage/pkg/stringid"
 	"github.com/containers/storage/pkg/truncindex"
+	digest "github.com/opencontainers/go-digest"
+	"github.com/pkg/errors"
 	"github.com/vbatts/tar-split/tar/asm"
 	"github.com/vbatts/tar-split/tar/storage"
 )
@@ -66,6 +67,38 @@ type Layer struct {
 	// mounted at the mount point.
 	MountCount int `json:"-"`
 
+	// Created is the datestamp for when this layer was created.  Older
+	// versions of the library did not track this information, so callers
+	// will likely want to use the IsZero() method to verify that a value
+	// is set before using it.
+	Created time.Time `json:"created,omitempty"`
+
+	// CompressedDigest is the digest of the blob that was last passed to
+	// ApplyDiff() or Put(), as it was presented to us.
+	CompressedDigest digest.Digest `json:"compressed-diff-digest,omitempty"`
+
+	// CompressedSize is the length of the blob that was last passed to
+	// ApplyDiff() or Put(), as it was presented to us.  If
+	// CompressedDigest is not set, this should be treated as if it were an
+	// uninitialized value.
+	CompressedSize int64 `json:"compressed-size,omitempty"`
+
+	// UncompressedDigest is the digest of the blob that was last passed to
+	// ApplyDiff() or Put(), after we decompressed it.  Often referred to
+	// as a DiffID.
+	UncompressedDigest digest.Digest `json:"diff-digest,omitempty"`
+
+	// UncompressedSize is the length of the blob that was last passed to
+	// ApplyDiff() or Put(), after we decompressed it.  If
+	// UncompressedDigest is not set, this should be treated as if it were
+	// an uninitialized value.
+	UncompressedSize int64 `json:"diff-size,omitempty"`
+
+	// CompressionType is the type of compression which we detected on the blob
+	// that was last passed to ApplyDiff() or Put().
+	CompressionType archive.Compression `json:"compression,omitempty"`
+
+	// Flags is arbitrary data about the layer.
 	Flags map[string]interface{} `json:"flags,omitempty"`
 }
 
@@ -75,12 +108,74 @@ type layerMountPoint struct {
 	MountCount int    `json:"count"`
 }
 
+// DiffOptions override the default behavior of Diff() methods.
+type DiffOptions struct {
+	// Compression, if set overrides the default compressor when generating a diff.
+	Compression *archive.Compression
+}
+
+// ROLayerStore wraps a graph driver, adding the ability to refer to layers by
+// name, and keeping track of parent-child relationships, along with a list of
+// all known layers.
+type ROLayerStore interface {
+	ROFileBasedStore
+	ROMetadataStore
+
+	// Exists checks if a layer with the specified name or ID is known.
+	Exists(id string) bool
+
+	// Get retrieves information about a layer given an ID or name.
+	Get(id string) (*Layer, error)
+
+	// Status returns an slice of key-value pairs, suitable for human consumption,
+	// relaying whatever status information the underlying driver can share.
+	Status() ([][2]string, error)
+
+	// Changes returns a slice of Change structures, which contain a pathname
+	// (Path) and a description of what sort of change (Kind) was made by the
+	// layer (either ChangeModify, ChangeAdd, or ChangeDelete), relative to a
+	// specified layer.  By default, the layer's parent is used as a reference.
+	Changes(from, to string) ([]archive.Change, error)
+
+	// Diff produces a tarstream which can be applied to a layer with the contents
+	// of the first layer to produce a layer with the contents of the second layer.
+	// By default, the parent of the second layer is used as the first
+	// layer, so it need not be specified.  Options can be used to override
+	// default behavior, but are also not required.
+	Diff(from, to string, options *DiffOptions) (io.ReadCloser, error)
+
+	// DiffSize produces an estimate of the length of the tarstream which would be
+	// produced by Diff.
+	DiffSize(from, to string) (int64, error)
+
+	// Size produces a cached value for the uncompressed size of the layer,
+	// if one is known, or -1 if it is not known.  If the layer can not be
+	// found, it returns an error.
+	Size(name string) (int64, error)
+
+	// Lookup attempts to translate a name to an ID.  Most methods do this
+	// implicitly.
+	Lookup(name string) (string, error)
+
+	// LayersByCompressedDigest returns a slice of the layers with the
+	// specified compressed digest value recorded for them.
+	LayersByCompressedDigest(d digest.Digest) ([]Layer, error)
+
+	// LayersByUncompressedDigest returns a slice of the layers with the
+	// specified uncompressed digest value recorded for them.
+	LayersByUncompressedDigest(d digest.Digest) ([]Layer, error)
+
+	// Layers returns a slice of the known layers.
+	Layers() ([]Layer, error)
+}
+
 // LayerStore wraps a graph driver, adding the ability to refer to layers by
 // name, and keeping track of parent-child relationships, along with a list of
 // all known layers.
 type LayerStore interface {
-	FileBasedStore
+	ROLayerStore
-	MetadataStore
+	RWFileBasedStore
+	RWMetadataStore
 	FlaggableStore
 
 	// Create creates a new layer, optionally giving it a specified ID rather than
@@ -98,20 +193,10 @@ type LayerStore interface {
 	// Put combines the functions of CreateWithFlags and ApplyDiff.
 	Put(id, parent string, names []string, mountLabel string, options map[string]string, writeable bool, flags map[string]interface{}, diff archive.Reader) (*Layer, int64, error)
 
-	// Exists checks if a layer with the specified name or ID is known.
-	Exists(id string) bool
-
-	// Get retrieves information about a layer given an ID or name.
-	Get(id string) (*Layer, error)
-
 	// SetNames replaces the list of names associated with a layer with the
 	// supplied values.
 	SetNames(id string, names []string) error
 
-	// Status returns an slice of key-value pairs, suitable for human consumption,
-	// relaying whatever status information the underlying driver can share.
-	Status() ([][2]string, error)
-
 	// Delete deletes a layer with the specified name or ID.
 	Delete(id string) error
 
@@ -126,48 +211,31 @@ type LayerStore interface {
 	// Unmount unmounts a layer when it is no longer in use.
 	Unmount(id string) error
 
-	// Changes returns a slice of Change structures, which contain a pathname
-	// (Path) and a description of what sort of change (Kind) was made by the
-	// layer (either ChangeModify, ChangeAdd, or ChangeDelete), relative to a
-	// specified layer.  By default, the layer's parent is used as a reference.
-	Changes(from, to string) ([]archive.Change, error)
-
-	// Diff produces a tarstream which can be applied to a layer with the contents
-	// of the first layer to produce a layer with the contents of the second layer.
-	// By default, the parent of the second layer is used as the first
-	// layer, so it need not be specified.
-	Diff(from, to string) (io.ReadCloser, error)
-
-	// DiffSize produces an estimate of the length of the tarstream which would be
-	// produced by Diff.
-	DiffSize(from, to string) (int64, error)
-
 	// ApplyDiff reads a tarstream which was created by a previous call to Diff and
 	// applies its changes to a specified layer.
 	ApplyDiff(to string, diff archive.Reader) (int64, error)
-
-	// Lookup attempts to translate a name to an ID.  Most methods do this
-	// implicitly.
-	Lookup(name string) (string, error)
-
-	// Layers returns a slice of the known layers.
-	Layers() ([]Layer, error)
 }
 
 type layerStore struct {
-	lockfile Locker
+	lockfile          Locker
-	rundir   string
+	rundir            string
-	driver   drivers.Driver
+	driver            drivers.Driver
-	layerdir string
+	layerdir          string
-	layers   []Layer
+	layers            []*Layer
-	idindex  *truncindex.TruncIndex
+	idindex           *truncindex.TruncIndex
-	byid     map[string]*Layer
+	byid              map[string]*Layer
-	byname   map[string]*Layer
+	byname            map[string]*Layer
-	bymount  map[string]*Layer
+	bymount           map[string]*Layer
+	bycompressedsum   map[digest.Digest][]string
+	byuncompressedsum map[digest.Digest][]string
 }
 
 func (r *layerStore) Layers() ([]Layer, error) {
-	return r.layers, nil
+	layers := make([]Layer, len(r.layers))
+	for i := range r.layers {
+		layers[i] = *(r.layers[i])
+	}
+	return layers, nil
 }
 
 func (r *layerStore) mountspath() string {
@@ -179,36 +247,41 @@ func (r *layerStore) layerspath() string {
 }
 
 func (r *layerStore) Load() error {
-	needSave := false
+	shouldSave := false
 	rpath := r.layerspath()
 	data, err := ioutil.ReadFile(rpath)
 	if err != nil && !os.IsNotExist(err) {
 		return err
 	}
-	layers := []Layer{}
+	layers := []*Layer{}
 	idlist := []string{}
 	ids := make(map[string]*Layer)
 	names := make(map[string]*Layer)
 	mounts := make(map[string]*Layer)
-	parents := make(map[string][]*Layer)
+	compressedsums := make(map[digest.Digest][]string)
+	uncompressedsums := make(map[digest.Digest][]string)
 	if err = json.Unmarshal(data, &layers); len(data) == 0 || err == nil {
 		for n, layer := range layers {
-			ids[layer.ID] = &layers[n]
+			ids[layer.ID] = layers[n]
 			idlist = append(idlist, layer.ID)
 			for _, name := range layer.Names {
 				if conflict, ok := names[name]; ok {
 					r.removeName(conflict, name)
-					needSave = true
+					shouldSave = true
 				}
-				names[name] = &layers[n]
+				names[name] = layers[n]
 			}
-			if pslice, ok := parents[layer.Parent]; ok {
+			if layer.CompressedDigest != "" {
-				parents[layer.Parent] = append(pslice, &layers[n])
+				compressedsums[layer.CompressedDigest] = append(compressedsums[layer.CompressedDigest], layer.ID)
-			} else {
+			}
-				parents[layer.Parent] = []*Layer{&layers[n]}
+			if layer.UncompressedDigest != "" {
+				uncompressedsums[layer.UncompressedDigest] = append(uncompressedsums[layer.UncompressedDigest], layer.ID)
 			}
 		}
 	}
+	if shouldSave && !r.IsReadWrite() {
+		return errors.New("layer store assigns the same name to multiple layers")
+	}
 	mpath := r.mountspath()
 	data, err = ioutil.ReadFile(mpath)
 	if err != nil && !os.IsNotExist(err) {
@@ -231,29 +304,35 @@ func (r *layerStore) Load() error {
 	r.byid = ids
 	r.byname = names
 	r.bymount = mounts
+	r.bycompressedsum = compressedsums
+	r.byuncompressedsum = uncompressedsums
 	err = nil
-	// Last step: try to remove anything that a previous user of this
+	// Last step: if we're writable, try to remove anything that a previous
-	// storage area marked for deletion but didn't manage to actually
+	// user of this storage area marked for deletion but didn't manage to
-	// delete.
+	// actually delete.
-	for _, layer := range r.layers {
+	if r.IsReadWrite() {
-		if cleanup, ok := layer.Flags[incompleteFlag]; ok {
+		for _, layer := range r.layers {
-			if b, ok := cleanup.(bool); ok && b {
+			if cleanup, ok := layer.Flags[incompleteFlag]; ok {
-				err = r.Delete(layer.ID)
+				if b, ok := cleanup.(bool); ok && b {
-				if err != nil {
+					err = r.Delete(layer.ID)
-					break
+					if err != nil {
+						break
+					}
+					shouldSave = true
 				}
-				needSave = true
 			}
 		}
-	}
+		if shouldSave {
-	if needSave {
+			return r.Save()
-		r.Touch()
+		}
-		return r.Save()
 	}
 	return err
 }
 
 func (r *layerStore) Save() error {
+	if !r.IsReadWrite() {
+		return errors.Wrapf(ErrStoreIsReadOnly, "not allowed to modify the layer store at %q", r.layerspath())
+	}
 	rpath := r.layerspath()
 	if err := os.MkdirAll(filepath.Dir(rpath), 0700); err != nil {
 		return err
@@ -283,6 +362,7 @@ func (r *layerStore) Save() error {
 	if err := ioutils.AtomicWriteFile(rpath, jldata, 0600); err != nil {
 		return err
 	}
+	defer r.Touch()
 	return ioutils.AtomicWriteFile(mpath, jmdata, 0600)
 }
 
@@ -314,6 +394,28 @@ func newLayerStore(rundir string, layerdir string, driver drivers.Driver) (Layer
 	return &rlstore, nil
 }
 
+func newROLayerStore(rundir string, layerdir string, driver drivers.Driver) (ROLayerStore, error) {
+	lockfile, err := GetROLockfile(filepath.Join(layerdir, "layers.lock"))
+	if err != nil {
+		return nil, err
+	}
+	lockfile.Lock()
+	defer lockfile.Unlock()
+	rlstore := layerStore{
+		lockfile: lockfile,
+		driver:   driver,
+		rundir:   rundir,
+		layerdir: layerdir,
+		byid:     make(map[string]*Layer),
+		bymount:  make(map[string]*Layer),
+		byname:   make(map[string]*Layer),
+	}
+	if err := rlstore.Load(); err != nil {
+		return nil, err
+	}
+	return &rlstore, nil
+}
+
 func (r *layerStore) lookup(id string) (*Layer, bool) {
 	if layer, ok := r.byid[id]; ok {
 		return layer, ok
@@ -326,7 +428,24 @@ func (r *layerStore) lookup(id string) (*Layer, bool) {
 	return nil, false
 }
 
+func (r *layerStore) Size(name string) (int64, error) {
+	layer, ok := r.lookup(name)
+	if !ok {
+		return -1, ErrLayerUnknown
+	}
+	// We use the presence of a non-empty digest as an indicator that the size value was intentionally set, and that
+	// a zero value is not just present because it was never set to anything else (which can happen if the layer was
+	// created by a version of this library that didn't keep track of digest and size information).
+	if layer.UncompressedDigest != "" {
+		return layer.UncompressedSize, nil
+	}
+	return -1, nil
+}
+
 func (r *layerStore) ClearFlag(id string, flag string) error {
+	if !r.IsReadWrite() {
+		return errors.Wrapf(ErrStoreIsReadOnly, "not allowed to clear flags on layers at %q", r.layerspath())
+	}
 	layer, ok := r.lookup(id)
 	if !ok {
 		return ErrLayerUnknown
@@ -336,6 +455,9 @@ func (r *layerStore) ClearFlag(id string, flag string) error {
 }
 
 func (r *layerStore) SetFlag(id string, flag string, value interface{}) error {
+	if !r.IsReadWrite() {
+		return errors.Wrapf(ErrStoreIsReadOnly, "not allowed to set flags on layers at %q", r.layerspath())
+	}
 	layer, ok := r.lookup(id)
 	if !ok {
 		return ErrLayerUnknown
@@ -349,6 +471,9 @@ func (r *layerStore) Status() ([][2]string, error) {
 }
 
 func (r *layerStore) Put(id, parent string, names []string, mountLabel string, options map[string]string, writeable bool, flags map[string]interface{}, diff archive.Reader) (layer *Layer, size int64, err error) {
+	if !r.IsReadWrite() {
+		return nil, -1, errors.Wrapf(ErrStoreIsReadOnly, "not allowed to create new layers at %q", r.layerspath())
+	}
 	size = -1
 	if err := os.MkdirAll(r.rundir, 0700); err != nil {
 		return nil, -1, err
@@ -383,15 +508,15 @@ func (r *layerStore) Put(id, parent string, names []string, mountLabel string, o
 		err = r.driver.Create(id, parent, mountLabel, options)
 	}
 	if err == nil {
-		newLayer := Layer{
+		layer = &Layer{
 			ID:         id,
 			Parent:     parent,
 			Names:      names,
 			MountLabel: mountLabel,
+			Created:    time.Now().UTC(),
 			Flags:      make(map[string]interface{}),
 		}
-		r.layers = append(r.layers, newLayer)
+		r.layers = append(r.layers, layer)
-		layer = &r.layers[len(r.layers)-1]
 		r.idindex.Add(id)
 		r.byid[id] = layer
 		for _, name := range names {
@@ -441,6 +566,9 @@ func (r *layerStore) Create(id, parent string, names []string, mountLabel string
 }
 
 func (r *layerStore) Mount(id, mountLabel string) (string, error) {
+	if !r.IsReadWrite() {
+		return "", errors.Wrapf(ErrStoreIsReadOnly, "not allowed to update mount locations for layers at %q", r.mountspath())
+	}
 	layer, ok := r.lookup(id)
 	if !ok {
 		return "", ErrLayerUnknown
@@ -466,6 +594,9 @@ func (r *layerStore) Mount(id, mountLabel string) (string, error) {
 }
 
 func (r *layerStore) Unmount(id string) error {
+	if !r.IsReadWrite() {
+		return errors.Wrapf(ErrStoreIsReadOnly, "not allowed to update mount locations for layers at %q", r.mountspath())
+	}
 	layer, ok := r.lookup(id)
 	if !ok {
 		layerByMount, ok := r.bymount[filepath.Clean(id)]
@@ -495,6 +626,9 @@ func (r *layerStore) removeName(layer *Layer, name string) {
 }
 
 func (r *layerStore) SetNames(id string, names []string) error {
+	if !r.IsReadWrite() {
+		return errors.Wrapf(ErrStoreIsReadOnly, "not allowed to change layer name assignments at %q", r.layerspath())
+	}
 	if layer, ok := r.lookup(id); ok {
 		for _, name := range layer.Names {
 			delete(r.byname, name)
@@ -519,6 +653,9 @@ func (r *layerStore) Metadata(id string) (string, error) {
 }
 
 func (r *layerStore) SetMetadata(id, metadata string) error {
+	if !r.IsReadWrite() {
+		return errors.Wrapf(ErrStoreIsReadOnly, "not allowed to modify layer metadata at %q", r.layerspath())
+	}
 	if layer, ok := r.lookup(id); ok {
 		layer.Metadata = metadata
 		return r.Save()
@@ -531,6 +668,9 @@ func (r *layerStore) tspath(id string) string {
 }
 
 func (r *layerStore) Delete(id string) error {
+	if !r.IsReadWrite() {
+		return errors.Wrapf(ErrStoreIsReadOnly, "not allowed to delete layers at %q", r.layerspath())
+	}
 	layer, ok := r.lookup(id)
 	if !ok {
 		return ErrLayerUnknown
@@ -549,13 +689,21 @@ func (r *layerStore) Delete(id string) error {
 		if layer.MountPoint != "" {
 			delete(r.bymount, layer.MountPoint)
 		}
-		newLayers := []Layer{}
+		toDeleteIndex := -1
-		for _, candidate := range r.layers {
+		for i, candidate := range r.layers {
-			if candidate.ID != id {
+			if candidate.ID == id {
-				newLayers = append(newLayers, candidate)
+				toDeleteIndex = i
+				break
+			}
+		}
+		if toDeleteIndex != -1 {
+			// delete the layer at toDeleteIndex
+			if toDeleteIndex == len(r.layers)-1 {
+				r.layers = r.layers[:len(r.layers)-1]
+			} else {
+				r.layers = append(r.layers[:toDeleteIndex], r.layers[toDeleteIndex+1:]...)
 			}
 		}
-		r.layers = newLayers
 		if err = r.Save(); err != nil {
 			return err
 		}
@@ -583,6 +731,9 @@ func (r *layerStore) Get(id string) (*Layer, error) {
 }
 
 func (r *layerStore) Wipe() error {
+	if !r.IsReadWrite() {
+		return errors.Wrapf(ErrStoreIsReadOnly, "not allowed to delete layers at %q", r.layerspath())
+	}
 	ids := []string{}
 	for id := range r.byid {
 		ids = append(ids, id)
@@ -657,48 +808,64 @@ func (r *layerStore) newFileGetter(id string) (drivers.FileGetCloser, error) {
 	}, nil
 }
 
-func (r *layerStore) Diff(from, to string) (io.ReadCloser, error) {
+func (r *layerStore) Diff(from, to string, options *DiffOptions) (io.ReadCloser, error) {
 	var metadata storage.Unpacker
 
 	from, to, toLayer, err := r.findParentAndLayer(from, to)
 	if err != nil {
 		return nil, ErrLayerUnknown
 	}
-	compression := archive.Uncompressed
+	// Default to applying the type of compression that we noted was used
-	if cflag, ok := toLayer.Flags[compressionFlag]; ok {
+	// for the layerdiff when it was applied.
-		if ctype, ok := cflag.(float64); ok {
+	compression := toLayer.CompressionType
-			compression = archive.Compression(ctype)
+	// If a particular compression type (or no compression) was selected,
-		} else if ctype, ok := cflag.(archive.Compression); ok {
+	// use that instead.
-			compression = archive.Compression(ctype)
+	if options != nil && options.Compression != nil {
-		}
+		compression = *options.Compression
 	}
+	maybeCompressReadCloser := func(rc io.ReadCloser) (io.ReadCloser, error) {
+		// Depending on whether or not compression is desired, return either the
+		// passed-in ReadCloser, or a new one that provides its readers with a
+		// compressed version of the data that the original would have provided
+		// to its readers.
+		if compression == archive.Uncompressed {
+			return rc, nil
+		}
+		preader, pwriter := io.Pipe()
+		compressor, err := archive.CompressStream(pwriter, compression)
+		if err != nil {
+			rc.Close()
+			pwriter.Close()
+			preader.Close()
+			return nil, err
+		}
+		go func() {
+			defer pwriter.Close()
+			defer compressor.Close()
+			defer rc.Close()
+			io.Copy(compressor, rc)
+		}()
+		return preader, nil
+	}
+
 	if from != toLayer.Parent {
 		diff, err := r.driver.Diff(to, from)
-		if err == nil && (compression != archive.Uncompressed) {
+		if err != nil {
-			preader, pwriter := io.Pipe()
+			return nil, err
-			compressor, err := archive.CompressStream(pwriter, compression)
-			if err != nil {
-				diff.Close()
-				pwriter.Close()
-				return nil, err
-			}
-			go func() {
-				io.Copy(compressor, diff)
-				diff.Close()
-				compressor.Close()
-				pwriter.Close()
-			}()
-			diff = preader
 		}
-		return diff, err
+		return maybeCompressReadCloser(diff)
 	}
 
 	tsfile, err := os.Open(r.tspath(to))
 	if err != nil {
-		if os.IsNotExist(err) {
+		if !os.IsNotExist(err) {
-			return r.driver.Diff(to, from)
+			return nil, err
 		}
-		return nil, err
+		diff, err := r.driver.Diff(to, from)
+		if err != nil {
+			return nil, err
+		}
+		return maybeCompressReadCloser(diff)
 	}
 	defer tsfile.Close()
 
@@ -720,33 +887,16 @@ func (r *layerStore) Diff(from, to string) (io.ReadCloser, error) {
 		return nil, err
 	}
 
-	var stream io.ReadCloser
+	tarstream := asm.NewOutputTarStream(fgetter, metadata)
-	if compression != archive.Uncompressed {
+	rc := ioutils.NewReadCloserWrapper(tarstream, func() error {
-		preader, pwriter := io.Pipe()
+		err1 := tarstream.Close()
-		compressor, err := archive.CompressStream(pwriter, compression)
-		if err != nil {
-			fgetter.Close()
-			pwriter.Close()
-			preader.Close()
-			return nil, err
-		}
-		go func() {
-			asm.WriteOutputTarStream(fgetter, metadata, compressor)
-			compressor.Close()
-			pwriter.Close()
-		}()
-		stream = preader
-	} else {
-		stream = asm.NewOutputTarStream(fgetter, metadata)
-	}
-	return ioutils.NewReadCloserWrapper(stream, func() error {
-		err1 := stream.Close()
 		err2 := fgetter.Close()
 		if err2 == nil {
 			return err1
 		}
 		return err2
-	}), nil
+	})
+	return maybeCompressReadCloser(rc)
 }
 
 func (r *layerStore) DiffSize(from, to string) (size int64, err error) {
@@ -758,6 +908,10 @@ func (r *layerStore) DiffSize(from, to string) (size int64, err error) {
 }
 
 func (r *layerStore) ApplyDiff(to string, diff archive.Reader) (size int64, err error) {
+	if !r.IsReadWrite() {
+		return -1, errors.Wrapf(ErrStoreIsReadOnly, "not allowed to modify layer contents at %q", r.layerspath())
+	}
+
 	layer, ok := r.lookup(to)
 	if !ok {
 		return -1, ErrLayerUnknown
@@ -770,7 +924,9 @@ func (r *layerStore) ApplyDiff(to string, diff archive.Reader) (size int64, err
 	}
 
 	compression := archive.DetectCompression(header[:n])
-	defragmented := io.MultiReader(bytes.NewBuffer(header[:n]), diff)
+	compressedDigest := digest.Canonical.Digester()
+	compressedCounter := ioutils.NewWriteCounter(compressedDigest.Hash())
+	defragmented := io.TeeReader(io.MultiReader(bytes.NewBuffer(header[:n]), diff), compressedCounter)
 
 	tsdata := bytes.Buffer{}
 	compressor, err := gzip.NewWriterLevel(&tsdata, gzip.BestSpeed)
@@ -778,15 +934,20 @@ func (r *layerStore) ApplyDiff(to string, diff archive.Reader) (size int64, err
 		compressor = gzip.NewWriter(&tsdata)
 	}
 	metadata := storage.NewJSONPacker(compressor)
-	decompressed, err := archive.DecompressStream(defragmented)
+	uncompressed, err := archive.DecompressStream(defragmented)
 	if err != nil {
 		return -1, err
 	}
-	payload, err := asm.NewInputTarStream(decompressed, metadata, storage.NewDiscardFilePutter())
+	uncompressedDigest := digest.Canonical.Digester()
+	uncompressedCounter := ioutils.NewWriteCounter(uncompressedDigest.Hash())
+	payload, err := asm.NewInputTarStream(io.TeeReader(uncompressed, uncompressedCounter), metadata, storage.NewDiscardFilePutter())
 	if err != nil {
 		return -1, err
 	}
 	size, err = r.driver.ApplyDiff(layer.ID, layer.Parent, payload)
+	if err != nil {
+		return -1, err
+	}
 	compressor.Close()
 	if err == nil {
 		if err := os.MkdirAll(filepath.Dir(r.tspath(layer.ID)), 0700); err != nil {
@@ -797,15 +958,57 @@ func (r *layerStore) ApplyDiff(to string, diff archive.Reader) (size int64, err
 		}
 	}
 
-	if compression != archive.Uncompressed {
+	updateDigestMap := func(m *map[digest.Digest][]string, oldvalue, newvalue digest.Digest, id string) {
-		layer.Flags[compressionFlag] = compression
+		var newList []string
-	} else {
+		if oldvalue != "" {
-		delete(layer.Flags, compressionFlag)
+			for _, value := range (*m)[oldvalue] {
+				if value != id {
+					newList = append(newList, value)
+				}
+			}
+			if len(newList) > 0 {
+				(*m)[oldvalue] = newList
+			} else {
+				delete(*m, oldvalue)
+			}
+		}
+		if newvalue != "" {
+			(*m)[newvalue] = append((*m)[newvalue], id)
+		}
 	}
+	updateDigestMap(&r.bycompressedsum, layer.CompressedDigest, compressedDigest.Digest(), layer.ID)
+	layer.CompressedDigest = compressedDigest.Digest()
+	layer.CompressedSize = compressedCounter.Count
+	updateDigestMap(&r.byuncompressedsum, layer.UncompressedDigest, uncompressedDigest.Digest(), layer.ID)
+	layer.UncompressedDigest = uncompressedDigest.Digest()
+	layer.UncompressedSize = uncompressedCounter.Count
+	layer.CompressionType = compression
+
+	err = r.Save()
 
 	return size, err
 }
 
+func (r *layerStore) layersByDigestMap(m map[digest.Digest][]string, d digest.Digest) ([]Layer, error) {
+	var layers []Layer
+	for _, layerID := range m[d] {
+		layer, ok := r.lookup(layerID)
+		if !ok {
+			return nil, ErrLayerUnknown
+		}
+		layers = append(layers, *layer)
+	}
+	return layers, nil
+}
+
+func (r *layerStore) LayersByCompressedDigest(d digest.Digest) ([]Layer, error) {
+	return r.layersByDigestMap(r.bycompressedsum, d)
+}
+
+func (r *layerStore) LayersByUncompressedDigest(d digest.Digest) ([]Layer, error) {
+	return r.layersByDigestMap(r.byuncompressedsum, d)
+}
+
 func (r *layerStore) Lock() {
 	r.lockfile.Lock()
 }
@@ -822,6 +1025,10 @@ func (r *layerStore) Modified() (bool, error) {
 	return r.lockfile.Modified()
 }
 
+func (r *layerStore) IsReadWrite() bool {
+	return r.lockfile.IsReadWrite()
+}
+
 func (r *layerStore) TouchedSince(when time.Time) bool {
 	return r.lockfile.TouchedSince(when)
 }

vendor/github.com/containers/storage/lockfile.go

@@ -1,14 +1,15 @@
 package storage
 
 import (
+	"fmt"
 	"os"
 	"path/filepath"
 	"sync"
 	"time"
 
-	"golang.org/x/sys/unix"
-
 	"github.com/containers/storage/pkg/stringid"
+	"github.com/pkg/errors"
+	"golang.org/x/sys/unix"
 )
 
 // A Locker represents a file lock where the file is used to cache an
@@ -27,43 +28,80 @@ type Locker interface {
 
 	// TouchedSince() checks if the most recent writer modified the file (likely using Touch()) after the specified time.
 	TouchedSince(when time.Time) bool
+
+	// IsReadWrite() checks if the lock file is read-write
+	IsReadWrite() bool
 }
 
 type lockfile struct {
-	mu   sync.Mutex
+	mu       sync.Mutex
-	file string
+	file     string
-	fd   uintptr
+	fd       uintptr
-	lw   string
+	lw       string
+	locktype int16
 }
 
 var (
 	lockfiles     map[string]*lockfile
 	lockfilesLock sync.Mutex
+	// ErrLockReadOnly indicates that the caller only took a read-only lock, and is not allowed to write
+	ErrLockReadOnly = errors.New("lock is not a read-write lock")
 )
 
-// GetLockfile opens a lock file, creating it if necessary.  The Locker object
+// GetLockfile opens a read-write lock file, creating it if necessary.  The
-// return will be returned unlocked.
+// Locker object it returns will be returned unlocked.
 func GetLockfile(path string) (Locker, error) {
 	lockfilesLock.Lock()
 	defer lockfilesLock.Unlock()
 	if lockfiles == nil {
 		lockfiles = make(map[string]*lockfile)
 	}
-	if locker, ok := lockfiles[filepath.Clean(path)]; ok {
+	cleanPath := filepath.Clean(path)
+	if locker, ok := lockfiles[cleanPath]; ok {
+		if !locker.IsReadWrite() {
+			return nil, errors.Wrapf(ErrLockReadOnly, "lock %q is a read-only lock", cleanPath)
+		}
 		return locker, nil
 	}
-	fd, err := unix.Open(filepath.Clean(path), os.O_RDWR|os.O_CREATE, unix.S_IRUSR|unix.S_IWUSR)
+	fd, err := unix.Open(cleanPath, os.O_RDWR|os.O_CREATE, unix.S_IRUSR|unix.S_IWUSR)
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrapf(err, "error opening %q", cleanPath)
 	}
-	locker := &lockfile{file: path, fd: uintptr(fd), lw: stringid.GenerateRandomID()}
+	unix.CloseOnExec(fd)
+	locker := &lockfile{file: path, fd: uintptr(fd), lw: stringid.GenerateRandomID(), locktype: unix.F_WRLCK}
 	lockfiles[filepath.Clean(path)] = locker
 	return locker, nil
 }
 
+// GetROLockfile opens a read-only lock file.  The Locker object it returns
+// will be returned unlocked.
+func GetROLockfile(path string) (Locker, error) {
+	lockfilesLock.Lock()
+	defer lockfilesLock.Unlock()
+	if lockfiles == nil {
+		lockfiles = make(map[string]*lockfile)
+	}
+	cleanPath := filepath.Clean(path)
+	if locker, ok := lockfiles[cleanPath]; ok {
+		if locker.IsReadWrite() {
+			return nil, fmt.Errorf("lock %q is a read-write lock", cleanPath)
+		}
+		return locker, nil
+	}
+	fd, err := unix.Open(cleanPath, os.O_RDONLY, 0)
+	if err != nil {
+		return nil, errors.Wrapf(err, "error opening %q", cleanPath)
+	}
+	unix.CloseOnExec(fd)
+	locker := &lockfile{file: path, fd: uintptr(fd), lw: stringid.GenerateRandomID(), locktype: unix.F_RDLCK}
+	lockfiles[filepath.Clean(path)] = locker
+	return locker, nil
+}
+
+// Lock locks the lock file
 func (l *lockfile) Lock() {
 	lk := unix.Flock_t{
-		Type:   unix.F_WRLCK,
+		Type:   l.locktype,
 		Whence: int16(os.SEEK_SET),
 		Start:  0,
 		Len:    0,
@@ -75,6 +113,7 @@ func (l *lockfile) Lock() {
 	}
 }
 
+// Unlock unlocks the lock file
 func (l *lockfile) Unlock() {
 	lk := unix.Flock_t{
 		Type:   unix.F_UNLCK,
@@ -89,6 +128,7 @@ func (l *lockfile) Unlock() {
 	l.mu.Unlock()
 }
 
+// Touch updates the lock file with the UID of the user
 func (l *lockfile) Touch() error {
 	l.lw = stringid.GenerateRandomID()
 	id := []byte(l.lw)
@@ -110,6 +150,7 @@ func (l *lockfile) Touch() error {
 	return nil
 }
 
+// Modified indicates if the lock file has been updated since the last time it was loaded
 func (l *lockfile) Modified() (bool, error) {
 	id := []byte(l.lw)
 	_, err := unix.Seek(int(l.fd), 0, os.SEEK_SET)
@@ -128,6 +169,7 @@ func (l *lockfile) Modified() (bool, error) {
 	return l.lw != lw, nil
 }
 
+// TouchedSince indicates if the lock file has been touched since the specified time
 func (l *lockfile) TouchedSince(when time.Time) bool {
 	st := unix.Stat_t{}
 	err := unix.Fstat(int(l.fd), &st)
@@ -137,3 +179,8 @@ func (l *lockfile) TouchedSince(when time.Time) bool {
 	touched := time.Unix(statTMtimeUnix(st))
 	return when.Before(touched)
 }
+
+// IsRWLock indicates if the lock file is a read-write lock
+func (l *lockfile) IsReadWrite() bool {
+	return (l.locktype == unix.F_WRLCK)
+}

vendor/github.com/containers/storage/pkg/archive/example_changes.go

@@ -0,0 +1,97 @@
+// +build ignore
+
+// Simple tool to create an archive stream from an old and new directory
+//
+// By default it will stream the comparison of two temporary directories with junk files
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/containers/storage/pkg/archive"
+)
+
+var (
+	flDebug  = flag.Bool("D", false, "debugging output")
+	flNewDir = flag.String("newdir", "", "")
+	flOldDir = flag.String("olddir", "", "")
+	log      = logrus.New()
+)
+
+func main() {
+	flag.Usage = func() {
+		fmt.Println("Produce a tar from comparing two directory paths. By default a demo tar is created of around 200 files (including hardlinks)")
+		fmt.Printf("%s [OPTIONS]\n", os.Args[0])
+		flag.PrintDefaults()
+	}
+	flag.Parse()
+	log.Out = os.Stderr
+	if (len(os.Getenv("DEBUG")) > 0) || *flDebug {
+		logrus.SetLevel(logrus.DebugLevel)
+	}
+	var newDir, oldDir string
+
+	if len(*flNewDir) == 0 {
+		var err error
+		newDir, err = ioutil.TempDir("", "storage-test-newDir")
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer os.RemoveAll(newDir)
+		if _, err := prepareUntarSourceDirectory(100, newDir, true); err != nil {
+			log.Fatal(err)
+		}
+	} else {
+		newDir = *flNewDir
+	}
+
+	if len(*flOldDir) == 0 {
+		oldDir, err := ioutil.TempDir("", "storage-test-oldDir")
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer os.RemoveAll(oldDir)
+	} else {
+		oldDir = *flOldDir
+	}
+
+	changes, err := archive.ChangesDirs(newDir, oldDir)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	a, err := archive.ExportChanges(newDir, changes)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer a.Close()
+
+	i, err := io.Copy(os.Stdout, a)
+	if err != nil && err != io.EOF {
+		log.Fatal(err)
+	}
+	fmt.Fprintf(os.Stderr, "wrote archive of %d bytes", i)
+}
+
+func prepareUntarSourceDirectory(numberOfFiles int, targetPath string, makeLinks bool) (int, error) {
+	fileData := []byte("fooo")
+	for n := 0; n < numberOfFiles; n++ {
+		fileName := fmt.Sprintf("file-%d", n)
+		if err := ioutil.WriteFile(path.Join(targetPath, fileName), fileData, 0700); err != nil {
+			return 0, err
+		}
+		if makeLinks {
+			if err := os.Link(path.Join(targetPath, fileName), path.Join(targetPath, fileName+"-link")); err != nil {
+				return 0, err
+			}
+		}
+	}
+	totalSize := numberOfFiles * len(fileData)
+	return totalSize, nil
+}

vendor/github.com/containers/storage/pkg/loopback/attach_loopback.go

@@ -38,7 +38,15 @@ func getNextFreeLoopbackIndex() (int, error) {
 	return index, err
 }
 
-func openNextAvailableLoopback(index int, sparseFile *os.File) (loopFile *os.File, err error) {
+func openNextAvailableLoopback(index int, sparseName string, sparseFile *os.File) (loopFile *os.File, err error) {
+	// Read information about the loopback file.
+	var st syscall.Stat_t
+	err = syscall.Fstat(int(sparseFile.Fd()), &st)
+	if err != nil {
+		logrus.Errorf("Error reading information about loopback file %s: %v", sparseName, err)
+		return nil, ErrAttachLoopbackDevice
+	}
+
 	// Start looking for a free /dev/loop
 	for {
 		target := fmt.Sprintf("/dev/loop%d", index)
@@ -77,6 +85,18 @@ func openNextAvailableLoopback(index int, sparseFile *os.File) (loopFile *os.Fil
 			// Otherwise, we keep going with the loop
 			continue
 		}
+
+		// Check if the loopback driver and underlying filesystem agree on the loopback file's
+		// device and inode numbers.
+		dev, ino, err := getLoopbackBackingFile(loopFile)
+		if err != nil {
+			logrus.Errorf("Error getting loopback backing file: %s", err)
+			return nil, ErrGetLoopbackBackingFile
+		}
+		if dev != st.Dev || ino != st.Ino {
+			logrus.Errorf("Loopback device and filesystem disagree on device/inode for %q: %#x(%d):%#x(%d) vs %#x(%d):%#x(%d)", sparseName, dev, dev, ino, ino, st.Dev, st.Dev, st.Ino, st.Ino)
+		}
+
 		// In case of success, we finished. Break the loop.
 		break
 	}
@@ -110,7 +130,7 @@ func AttachLoopDevice(sparseName string) (loop *os.File, err error) {
 	}
 	defer sparseFile.Close()
 
-	loopFile, err := openNextAvailableLoopback(startIndex, sparseFile)
+	loopFile, err := openNextAvailableLoopback(startIndex, sparseName, sparseFile)
 	if err != nil {
 		return nil, err
 	}

vendor/github.com/containers/storage/pkg/plugins/discovery.go

@@ -15,8 +15,8 @@ import (
 var (
 	// ErrNotFound plugin not found
 	ErrNotFound = errors.New("plugin not found")
-	socketsPath = "/run/oci-storage/plugins"
+	socketsPath = "/run/containers/storage/plugins"
-	specsPaths  = []string{"/etc/oci-storage/plugins", "/usr/lib/oci-storage/plugins"}
+	specsPaths  = []string{"/etc/containers/storage/plugins", "/usr/lib/containers/storage/plugins"}
 )
 
 // localRegistry defines a registry that is local (using unix socket).

vendor/github.com/containers/storage/pkg/plugins/plugins.go

@@ -3,10 +3,11 @@
 //
 // Storage discovers plugins by looking for them in the plugin directory whenever
 // a user or container tries to use one by name. UNIX domain socket files must
-// be located under /run/oci-storage/plugins, whereas spec files can be located
+// be located under /run/containers/storage/plugins, whereas spec files can be
-// either under /etc/oci-storage/plugins or /usr/lib/oci-storage/plugins. This
+// located either under /etc/containers/storage/plugins or
-// is handled by the Registry interface, which lets you list all plugins or get
+// /usr/lib/containers/storage/plugins. This is handled by the Registry
-// a plugin by its name if it exists.
+// interface, which lets you list all plugins or get a plugin by its name if it
+// exists.
 //
 // The plugins need to implement an HTTP server and bind this to the UNIX socket
 // or the address specified in the spec files.

vendor/github.com/containers/storage/storageversion/version_lib.go

@@ -1,13 +0,0 @@
-// +build !containersstorageautogen
-
-// Package storageversion is auto-generated at build-time
-package storageversion
-
-// Default build-time variable for library-import.
-// This file is overridden on build with build-time informations.
-const (
-	GitCommit string = "library-import"
-	Version   string = "library-import"
-	BuildTime string = "library-import"
-	IAmStatic string = "library-import"
-)

vendor/github.com/containers/storage/vendor.conf

@@ -1,3 +1,4 @@
+github.com/BurntSushi/toml master
 github.com/Microsoft/go-winio 307e919c663683a9000576fdc855acaf9534c165
 github.com/Microsoft/hcsshim 0f615c198a84e0344b4ed49c464d8833d4648dfc
 github.com/Sirupsen/logrus 61e43dc76f7ee59a82bdf3d71033dc12bea4c77d
@@ -7,9 +8,11 @@ github.com/docker/go-units 0dadbb0345b35ec7ef35e228dabb8de89a65bf52
 github.com/go-check/check 20d25e2804050c1cd24a7eea1e7a6447dd0e74ec
 github.com/mattn/go-shellwords 753a2322a99f87c0eff284980e77f53041555bc6
 github.com/mistifyio/go-zfs c0224de804d438efd11ea6e52ada8014537d6062
+github.com/opencontainers/go-digest master
 github.com/opencontainers/runc 6c22e77604689db8725fa866f0f2ec0b3e8c3a07
 github.com/opencontainers/selinux ba1aefe8057f1d0cfb8e88d0ec1dc85925ef987d
 github.com/pborman/uuid 1b00554d822231195d1babd97ff4a781231955c9
+github.com/pkg/errors master
 github.com/tchap/go-patricia v2.2.6
 github.com/vbatts/tar-split bd4c5d64c3e9297f410025a3b1bd0c58f659e721
 github.com/vdemeester/shakers 24d7f1d6a71aa5d9cbe7390e4afb66b7eef9e1b3