vendor: update c/i@fb36437e0f

This change includes the docker-archive: transport, allowing for
entirely local manipulation of Docker images.

Signed-off-by: Aleksa Sarai <asarai@suse.de>

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

@@ -0,0 +1,57 @@
+package archive
+
+import (
+	"io"
+	"os"
+
+	"github.com/containers/image/docker/tarfile"
+	"github.com/containers/image/types"
+	"github.com/pkg/errors"
+)
+
+type archiveImageDestination struct {
+	*tarfile.Destination // Implements most of types.ImageDestination
+	ref                  archiveReference
+	writer               io.Closer
+}
+
+func newImageDestination(ctx *types.SystemContext, ref archiveReference) (types.ImageDestination, error) {
+	if ref.destinationRef == nil {
+		return nil, errors.Errorf("docker-archive: destination reference not supplied (must be of form <path>:<reference:tag>)")
+	}
+	fh, err := os.OpenFile(ref.path, os.O_WRONLY|os.O_EXCL|os.O_CREATE, 0644)
+	if err != nil {
+		// FIXME: It should be possible to modify archives, but the only really
+		//        sane way of doing it is to create a copy of the image, modify
+		//        it and then do a rename(2).
+		if os.IsExist(err) {
+			err = errors.New("docker-archive doesn't support modifying existing images")
+		}
+		return nil, err
+	}
+
+	return &archiveImageDestination{
+		Destination: tarfile.NewDestination(fh, ref.destinationRef),
+		ref:         ref,
+		writer:      fh,
+	}, nil
+}
+
+// Reference returns the reference used to set up this destination.  Note that this should directly correspond to user's intent,
+// e.g. it should use the public hostname instead of the result of resolving CNAMEs or following redirects.
+func (d *archiveImageDestination) Reference() types.ImageReference {
+	return d.ref
+}
+
+// Close removes resources associated with an initialized ImageDestination, if any.
+func (d *archiveImageDestination) Close() error {
+	return d.writer.Close()
+}
+
+// Commit marks the process of storing the image as successful and asks for the image to be persisted.
+// WARNING: This does not have any transactional semantics:
+// - Uploaded data MAY be visible to others before Commit() is called
+// - Uploaded data MAY be removed or MAY remain around if Close() is called without Commit() (i.e. rollback is allowed but not guaranteed)
+func (d *archiveImageDestination) Commit() error {
+	return d.Destination.Commit()
+}

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

@@ -0,0 +1,36 @@
+package archive
+
+import (
+	"github.com/Sirupsen/logrus"
+	"github.com/containers/image/docker/tarfile"
+	"github.com/containers/image/types"
+)
+
+type archiveImageSource struct {
+	*tarfile.Source // Implements most of types.ImageSource
+	ref             archiveReference
+}
+
+// newImageSource returns a types.ImageSource for the specified image reference.
+// The caller must call .Close() on the returned ImageSource.
+func newImageSource(ctx *types.SystemContext, ref archiveReference) types.ImageSource {
+	if ref.destinationRef != nil {
+		logrus.Warnf("docker-archive: references are not supported for sources (ignoring)")
+	}
+	src := tarfile.NewSource(ref.path)
+	return &archiveImageSource{
+		Source: src,
+		ref:    ref,
+	}
+}
+
+// Reference returns the reference used to set up this source, _as specified by the user_
+// (not as the image itself, or its underlying storage, claims).  This can be used e.g. to determine which public keys are trusted for this image.
+func (s *archiveImageSource) Reference() types.ImageReference {
+	return s.ref
+}
+
+// Close removes resources associated with an initialized ImageSource, if any.
+func (s *archiveImageSource) Close() error {
+	return nil
+}

vendor/github.com/containers/image/docker/archive/transport.go

@@ -0,0 +1,155 @@
+package archive
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/containers/image/docker/reference"
+	ctrImage "github.com/containers/image/image"
+	"github.com/containers/image/transports"
+	"github.com/containers/image/types"
+	"github.com/pkg/errors"
+)
+
+func init() {
+	transports.Register(Transport)
+}
+
+// Transport is an ImageTransport for local Docker archives.
+var Transport = archiveTransport{}
+
+type archiveTransport struct{}
+
+func (t archiveTransport) Name() string {
+	return "docker-archive"
+}
+
+// ParseReference converts a string, which should not start with the ImageTransport.Name prefix, into an ImageReference.
+func (t archiveTransport) ParseReference(reference string) (types.ImageReference, error) {
+	return ParseReference(reference)
+}
+
+// ValidatePolicyConfigurationScope checks that scope is a valid name for a signature.PolicyTransportScopes keys
+// (i.e. a valid PolicyConfigurationIdentity() or PolicyConfigurationNamespaces() return value).
+// It is acceptable to allow an invalid value which will never be matched, it can "only" cause user confusion.
+// scope passed to this function will not be "", that value is always allowed.
+func (t archiveTransport) ValidatePolicyConfigurationScope(scope string) error {
+	// See the explanation in archiveReference.PolicyConfigurationIdentity.
+	return errors.New(`docker-archive: does not support any scopes except the default "" one`)
+}
+
+// archiveReference is an ImageReference for Docker images.
+type archiveReference struct {
+	destinationRef reference.NamedTagged // only used for destinations
+	path           string
+}
+
+// ParseReference converts a string, which should not start with the ImageTransport.Name prefix, into an Docker ImageReference.
+func ParseReference(refString string) (types.ImageReference, error) {
+	if refString == "" {
+		return nil, errors.Errorf("docker-archive reference %s isn't of the form <path>[:<reference>]", refString)
+	}
+
+	parts := strings.SplitN(refString, ":", 2)
+	path := parts[0]
+	var destinationRef reference.NamedTagged
+
+	// A :tag was specified, which is only necessary for destinations.
+	if len(parts) == 2 {
+		ref, err := reference.ParseNormalizedNamed(parts[1])
+		if err != nil {
+			return nil, errors.Wrapf(err, "docker-archive parsing reference")
+		}
+		ref = reference.TagNameOnly(ref)
+
+		if _, isDigest := ref.(reference.Canonical); isDigest {
+			return nil, errors.Errorf("docker-archive doesn't support digest references: %s", refString)
+		}
+
+		refTagged, isTagged := ref.(reference.NamedTagged)
+		if !isTagged {
+			// Really shouldn't be hit...
+			return nil, errors.Errorf("internal error: reference is not tagged even after reference.TagNameOnly: %s", refString)
+		}
+		destinationRef = refTagged
+	}
+
+	return archiveReference{
+		destinationRef: destinationRef,
+		path:           path,
+	}, nil
+}
+
+func (ref archiveReference) Transport() types.ImageTransport {
+	return Transport
+}
+
+// StringWithinTransport returns a string representation of the reference, which MUST be such that
+// reference.Transport().ParseReference(reference.StringWithinTransport()) returns an equivalent reference.
+// NOTE: The returned string is not promised to be equal to the original input to ParseReference;
+// e.g. default attribute values omitted by the user may be filled in in the return value, or vice versa.
+// WARNING: Do not use the return value in the UI to describe an image, it does not contain the Transport().Name() prefix.
+func (ref archiveReference) StringWithinTransport() string {
+	if ref.destinationRef == nil {
+		return ref.path
+	}
+	return fmt.Sprintf("%s:%s", ref.path, ref.destinationRef.String())
+}
+
+// DockerReference returns a Docker reference associated with this reference
+// (fully explicit, i.e. !reference.IsNameOnly, but reflecting user intent,
+// not e.g. after redirect or alias processing), or nil if unknown/not applicable.
+func (ref archiveReference) DockerReference() reference.Named {
+	return ref.destinationRef
+}
+
+// PolicyConfigurationIdentity returns a string representation of the reference, suitable for policy lookup.
+// This MUST reflect user intent, not e.g. after processing of third-party redirects or aliases;
+// The value SHOULD be fully explicit about its semantics, with no hidden defaults, AND canonical
+// (i.e. various references with exactly the same semantics should return the same configuration identity)
+// It is fine for the return value to be equal to StringWithinTransport(), and it is desirable but
+// not required/guaranteed that it will be a valid input to Transport().ParseReference().
+// Returns "" if configuration identities for these references are not supported.
+func (ref archiveReference) PolicyConfigurationIdentity() string {
+	// Punt, the justification is similar to dockerReference.PolicyConfigurationIdentity.
+	return ""
+}
+
+// PolicyConfigurationNamespaces returns a list of other policy configuration namespaces to search
+// for if explicit configuration for PolicyConfigurationIdentity() is not set.  The list will be processed
+// in order, terminating on first match, and an implicit "" is always checked at the end.
+// It is STRONGLY recommended for the first element, if any, to be a prefix of PolicyConfigurationIdentity(),
+// and each following element to be a prefix of the element preceding it.
+func (ref archiveReference) PolicyConfigurationNamespaces() []string {
+	// TODO
+	return []string{}
+}
+
+// NewImage returns a types.Image for this reference, possibly specialized for this ImageTransport.
+// The caller must call .Close() on the returned Image.
+// NOTE: If any kind of signature verification should happen, build an UnparsedImage from the value returned by NewImageSource,
+// verify that UnparsedImage, and convert it into a real Image via image.FromUnparsedImage.
+func (ref archiveReference) NewImage(ctx *types.SystemContext) (types.Image, error) {
+	src := newImageSource(ctx, ref)
+	return ctrImage.FromSource(src)
+}
+
+// NewImageSource returns a types.ImageSource for this reference,
+// asking the backend to use a manifest from requestedManifestMIMETypes if possible.
+// nil requestedManifestMIMETypes means manifest.DefaultRequestedManifestMIMETypes.
+// The caller must call .Close() on the returned ImageSource.
+func (ref archiveReference) NewImageSource(ctx *types.SystemContext, requestedManifestMIMETypes []string) (types.ImageSource, error) {
+	return newImageSource(ctx, ref), nil
+}
+
+// NewImageDestination returns a types.ImageDestination for this reference.
+// The caller must call .Close() on the returned ImageDestination.
+func (ref archiveReference) NewImageDestination(ctx *types.SystemContext) (types.ImageDestination, error) {
+	return newImageDestination(ctx, ref)
+}
+
+// DeleteImage deletes the named image from the registry, if supported.
+func (ref archiveReference) DeleteImage(ctx *types.SystemContext) error {
+	// Not really supported, for safety reasons.
+	return errors.New("Deleting images not implemented for docker-archive: images")
+}

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

@@ -1,36 +1,26 @@
 package daemon
 
 import (
-	"archive/tar"
-	"bytes"
-	"encoding/json"
-	"fmt"
 	"io"
-	"io/ioutil"
-	"os"
-	"time"
 
 	"github.com/Sirupsen/logrus"
 	"github.com/containers/image/docker/reference"
-	"github.com/containers/image/manifest"
+	"github.com/containers/image/docker/tarfile"
 	"github.com/containers/image/types"
 	"github.com/docker/docker/client"
-	"github.com/opencontainers/go-digest"
 	"github.com/pkg/errors"
 	"golang.org/x/net/context"
 )
 
 type daemonImageDestination struct {
 	ref                  daemonReference
-	namedTaggedRef reference.NamedTagged // Strictly speaking redundant with ref above; having the field makes it structurally impossible for later users to fail.
+	*tarfile.Destination // Implements most of types.ImageDestination
 	// For talking to imageLoadGoroutine
 	goroutineCancel context.CancelFunc
 	statusChannel   <-chan error
 	writer          *io.PipeWriter
-	tar             *tar.Writer
 	// Other state
 	committed bool // writer has been closed
-	blobs     map[digest.Digest]types.BlobInfo // list of already-sent blobs
 }
 
 // newImageDestination returns a types.ImageDestination for the specified image reference.
@@ -57,13 +47,11 @@ func newImageDestination(systemCtx *types.SystemContext, ref daemonReference) (t
 
 	return &daemonImageDestination{
 		ref:             ref,
-		namedTaggedRef:  namedTaggedRef,
+		Destination:     tarfile.NewDestination(writer, namedTaggedRef),
 		goroutineCancel: goroutineCancel,
 		statusChannel:   statusChannel,
 		writer:          writer,
-		tar:             tar.NewWriter(writer),
 		committed:       false,
-		blobs:           make(map[digest.Digest]types.BlobInfo),
 	}, nil
 }
 
@@ -115,205 +103,13 @@ func (d *daemonImageDestination) Reference() types.ImageReference {
 	return d.ref
 }
 
-// SupportedManifestMIMETypes tells which manifest mime types the destination supports
-// If an empty slice or nil it's returned, then any mime type can be tried to upload
-func (d *daemonImageDestination) SupportedManifestMIMETypes() []string {
-	return []string{
-		manifest.DockerV2Schema2MediaType, // We rely on the types.Image.UpdatedImage schema conversion capabilities.
-	}
-}
-
-// SupportsSignatures returns an error (to be displayed to the user) if the destination certainly can't store signatures.
-// Note: It is still possible for PutSignatures to fail if SupportsSignatures returns nil.
-func (d *daemonImageDestination) SupportsSignatures() error {
-	return errors.Errorf("Storing signatures for docker-daemon: destinations is not supported")
-}
-
-// ShouldCompressLayers returns true iff it is desirable to compress layer blobs written to this destination.
-func (d *daemonImageDestination) ShouldCompressLayers() bool {
-	return false
-}
-
-// AcceptsForeignLayerURLs returns false iff foreign layers in manifest should be actually
-// uploaded to the image destination, true otherwise.
-func (d *daemonImageDestination) AcceptsForeignLayerURLs() 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.
-// WARNING: The contents of stream are being verified on the fly.  Until stream.Read() returns io.EOF, the contents of the data SHOULD NOT be available
-// to any other readers for download using the supplied digest.
-// If stream.Read() at any time, ESPECIALLY at end of input, returns an error, PutBlob MUST 1) fail, and 2) delete any data stored so far.
-func (d *daemonImageDestination) PutBlob(stream io.Reader, inputInfo types.BlobInfo) (types.BlobInfo, error) {
-	if inputInfo.Digest.String() == "" {
-		return types.BlobInfo{}, errors.Errorf(`Can not stream a blob with unknown digest to "docker-daemon:"`)
-	}
-
-	ok, size, err := d.HasBlob(inputInfo)
-	if err != nil {
-		return types.BlobInfo{}, err
-	}
-	if ok {
-		return types.BlobInfo{Digest: inputInfo.Digest, Size: size}, nil
-	}
-
-	if inputInfo.Size == -1 { // Ouch, we need to stream the blob into a temporary file just to determine the size.
-		logrus.Debugf("docker-daemon: input with unknown size, streaming to disk first…")
-		streamCopy, err := ioutil.TempFile(temporaryDirectoryForBigFiles, "docker-daemon-blob")
-		if err != nil {
-			return types.BlobInfo{}, err
-		}
-		defer os.Remove(streamCopy.Name())
-		defer streamCopy.Close()
-
-		size, err := io.Copy(streamCopy, stream)
-		if err != nil {
-			return types.BlobInfo{}, err
-		}
-		_, err = streamCopy.Seek(0, os.SEEK_SET)
-		if err != nil {
-			return types.BlobInfo{}, err
-		}
-		inputInfo.Size = size // inputInfo is a struct, so we are only modifying our copy.
-		stream = streamCopy
-		logrus.Debugf("… streaming done")
-	}
-
-	digester := digest.Canonical.Digester()
-	tee := io.TeeReader(stream, digester.Hash())
-	if err := d.sendFile(inputInfo.Digest.String(), inputInfo.Size, tee); err != nil {
-		return types.BlobInfo{}, err
-	}
-	d.blobs[inputInfo.Digest] = types.BlobInfo{Digest: digester.Digest(), Size: inputInfo.Size}
-	return types.BlobInfo{Digest: digester.Digest(), Size: inputInfo.Size}, nil
-}
-
-// HasBlob returns true iff the image destination already contains a blob with the matching digest which can be reapplied using ReapplyBlob.
-// Unlike PutBlob, the digest can not be empty.  If HasBlob returns true, the size of the blob must also be returned.
-// If the destination does not contain the blob, or it is unknown, HasBlob ordinarily returns (false, -1, nil);
-// it returns a non-nil error only on an unexpected failure.
-func (d *daemonImageDestination) HasBlob(info types.BlobInfo) (bool, int64, error) {
-	if info.Digest == "" {
-		return false, -1, errors.Errorf(`"Can not check for a blob with unknown digest`)
-	}
-	if blob, ok := d.blobs[info.Digest]; ok {
-		return true, blob.Size, nil
-	}
-	return false, -1, nil
-}
-
-func (d *daemonImageDestination) ReapplyBlob(info types.BlobInfo) (types.BlobInfo, error) {
-	return info, nil
-}
-
-func (d *daemonImageDestination) PutManifest(m []byte) error {
-	var man schema2Manifest
-	if err := json.Unmarshal(m, &man); err != nil {
-		return errors.Wrap(err, "Error parsing manifest")
-	}
-	if man.SchemaVersion != 2 || man.MediaType != manifest.DockerV2Schema2MediaType {
-		return errors.Errorf("Unsupported manifest type, need a Docker schema 2 manifest")
-	}
-
-	layerPaths := []string{}
-	for _, l := range man.Layers {
-		layerPaths = append(layerPaths, l.Digest.String())
-	}
-
-	// For github.com/docker/docker consumers, this works just as well as
-	//   refString := d.namedTaggedRef.String()  [i.e. d.ref.ref.String()]
-	// because when reading the RepoTags strings, github.com/docker/docker/reference
-	// normalizes both of them to the same value.
-	//
-	// Doing it this way to include the normalized-out `docker.io[/library]` does make
-	// a difference for github.com/projectatomic/docker consumers, with the
-	// “Add --add-registry and --block-registry options to docker daemon” patch.
-	// These consumers treat reference strings which include a hostname and reference
-	// strings without a hostname differently.
-	//
-	// Using the host name here is more explicit about the intent, and it has the same
-	// effect as (docker pull) in projectatomic/docker, which tags the result using
-	// a hostname-qualified reference.
-	// See https://github.com/containers/image/issues/72 for a more detailed
-	// analysis and explanation.
-	refString := fmt.Sprintf("%s:%s", d.namedTaggedRef.Name(), d.namedTaggedRef.Tag())
-
-	items := []manifestItem{{
-		Config:       man.Config.Digest.String(),
-		RepoTags:     []string{refString},
-		Layers:       layerPaths,
-		Parent:       "",
-		LayerSources: nil,
-	}}
-	itemsBytes, err := json.Marshal(&items)
-	if err != nil {
-		return err
-	}
-
-	// FIXME? Do we also need to support the legacy format?
-	return d.sendFile(manifestFileName, int64(len(itemsBytes)), bytes.NewReader(itemsBytes))
-}
-
-type tarFI struct {
-	path string
-	size int64
-}
-
-func (t *tarFI) Name() string {
-	return t.path
-}
-func (t *tarFI) Size() int64 {
-	return t.size
-}
-func (t *tarFI) Mode() os.FileMode {
-	return 0444
-}
-func (t *tarFI) ModTime() time.Time {
-	return time.Unix(0, 0)
-}
-func (t *tarFI) IsDir() bool {
-	return false
-}
-func (t *tarFI) Sys() interface{} {
-	return nil
-}
-
-// sendFile sends a file into the tar stream.
-func (d *daemonImageDestination) sendFile(path string, expectedSize int64, stream io.Reader) error {
-	hdr, err := tar.FileInfoHeader(&tarFI{path: path, size: expectedSize}, "")
-	if err != nil {
-		return nil
-	}
-	logrus.Debugf("Sending as tar file %s", path)
-	if err := d.tar.WriteHeader(hdr); err != nil {
-		return err
-	}
-	size, err := io.Copy(d.tar, stream)
-	if err != nil {
-		return err
-	}
-	if size != expectedSize {
-		return errors.Errorf("Size mismatch when copying %s, expected %d, got %d", path, expectedSize, size)
-	}
-	return nil
-}
-
-func (d *daemonImageDestination) PutSignatures(signatures [][]byte) error {
-	if len(signatures) != 0 {
-		return errors.Errorf("Storing signatures for docker-daemon: destinations is not supported")
-	}
-	return nil
-}
-
 // Commit marks the process of storing the image as successful and asks for the image to be persisted.
 // WARNING: This does not have any transactional semantics:
 // - Uploaded data MAY be visible to others before Commit() is called
 // - Uploaded data MAY be removed or MAY remain around if Close() is called without Commit() (i.e. rollback is allowed but not guaranteed)
 func (d *daemonImageDestination) Commit() error {
 	logrus.Debugf("docker-daemon: Closing tar stream")
-	if err := d.tar.Close(); err != nil {
+	if err := d.Destination.Commit(); err != nil {
 		return err
 	}
 	if err := d.writer.Close(); err != nil {

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

@@ -1,19 +1,13 @@
 package daemon
 
 import (
-	"archive/tar"
-	"bytes"
-	"encoding/json"
 	"io"
 	"io/ioutil"
 	"os"
-	"path"
 
-	"github.com/containers/image/manifest"
+	"github.com/containers/image/docker/tarfile"
-	"github.com/containers/image/pkg/compression"
 	"github.com/containers/image/types"
 	"github.com/docker/docker/client"
-	"github.com/opencontainers/go-digest"
 	"github.com/pkg/errors"
 	"golang.org/x/net/context"
 )
@@ -22,15 +16,8 @@ const temporaryDirectoryForBigFiles = "/var/tmp" // Do not use the system defaul
 
 type daemonImageSource struct {
 	ref             daemonReference
+	*tarfile.Source // Implements most of types.ImageSource
 	tarCopyPath     string
-	// The following data is only available after ensureCachedDataIsPresent() succeeds
-	tarManifest       *manifestItem // nil if not available yet.
-	configBytes       []byte
-	configDigest      digest.Digest
-	orderedDiffIDList []diffID
-	knownLayers       map[diffID]*layerInfo
-	// Other state
-	generatedManifest []byte // Private cache for GetManifest(), nil if not set yet.
 }
 
 type layerInfo struct {
@@ -81,6 +68,7 @@ func newImageSource(ctx *types.SystemContext, ref daemonReference) (types.ImageS
 	succeeded = true
 	return &daemonImageSource{
 		ref:         ref,
+		Source:      tarfile.NewSource(tarCopyFile.Name()),
 		tarCopyPath: tarCopyFile.Name(),
 	}, nil
 }
@@ -95,310 +83,3 @@ func (s *daemonImageSource) Reference() types.ImageReference {
 func (s *daemonImageSource) Close() error {
 	return os.Remove(s.tarCopyPath)
 }
-
-// tarReadCloser is a way to close the backing file of a tar.Reader when the user no longer needs the tar component.
-type tarReadCloser struct {
-	*tar.Reader
-	backingFile *os.File
-}
-
-func (t *tarReadCloser) Close() error {
-	return t.backingFile.Close()
-}
-
-// openTarComponent returns a ReadCloser for the specific file within the archive.
-// This is linear scan; we assume that the tar file will have a fairly small amount of files (~layers),
-// and that filesystem caching will make the repeated seeking over the (uncompressed) tarCopyPath cheap enough.
-// The caller should call .Close() on the returned stream.
-func (s *daemonImageSource) openTarComponent(componentPath string) (io.ReadCloser, error) {
-	f, err := os.Open(s.tarCopyPath)
-	if err != nil {
-		return nil, err
-	}
-	succeeded := false
-	defer func() {
-		if !succeeded {
-			f.Close()
-		}
-	}()
-
-	tarReader, header, err := findTarComponent(f, componentPath)
-	if err != nil {
-		return nil, err
-	}
-	if header == nil {
-		return nil, os.ErrNotExist
-	}
-	if header.FileInfo().Mode()&os.ModeType == os.ModeSymlink { // FIXME: untested
-		// We follow only one symlink; so no loops are possible.
-		if _, err := f.Seek(0, os.SEEK_SET); err != nil {
-			return nil, err
-		}
-		// The new path could easily point "outside" the archive, but we only compare it to existing tar headers without extracting the archive,
-		// so we don't care.
-		tarReader, header, err = findTarComponent(f, path.Join(path.Dir(componentPath), header.Linkname))
-		if err != nil {
-			return nil, err
-		}
-		if header == nil {
-			return nil, os.ErrNotExist
-		}
-	}
-
-	if !header.FileInfo().Mode().IsRegular() {
-		return nil, errors.Errorf("Error reading tar archive component %s: not a regular file", header.Name)
-	}
-	succeeded = true
-	return &tarReadCloser{Reader: tarReader, backingFile: f}, nil
-}
-
-// findTarComponent returns a header and a reader matching path within inputFile,
-// or (nil, nil, nil) if not found.
-func findTarComponent(inputFile io.Reader, path string) (*tar.Reader, *tar.Header, error) {
-	t := tar.NewReader(inputFile)
-	for {
-		h, err := t.Next()
-		if err == io.EOF {
-			break
-		}
-		if err != nil {
-			return nil, nil, err
-		}
-		if h.Name == path {
-			return t, h, nil
-		}
-	}
-	return nil, nil, nil
-}
-
-// readTarComponent returns full contents of componentPath.
-func (s *daemonImageSource) readTarComponent(path string) ([]byte, error) {
-	file, err := s.openTarComponent(path)
-	if err != nil {
-		return nil, errors.Wrapf(err, "Error loading tar component %s", path)
-	}
-	defer file.Close()
-	bytes, err := ioutil.ReadAll(file)
-	if err != nil {
-		return nil, err
-	}
-	return bytes, nil
-}
-
-// ensureCachedDataIsPresent loads data necessary for any of the public accessors.
-func (s *daemonImageSource) ensureCachedDataIsPresent() error {
-	if s.tarManifest != nil {
-		return nil
-	}
-
-	// Read and parse manifest.json
-	tarManifest, err := s.loadTarManifest()
-	if err != nil {
-		return err
-	}
-
-	// Read and parse config.
-	configBytes, err := s.readTarComponent(tarManifest.Config)
-	if err != nil {
-		return err
-	}
-	var parsedConfig dockerImage // 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)
-	}
-
-	knownLayers, err := s.prepareLayerData(tarManifest, &parsedConfig)
-	if err != nil {
-		return err
-	}
-
-	// Success; commit.
-	s.tarManifest = tarManifest
-	s.configBytes = configBytes
-	s.configDigest = digest.FromBytes(configBytes)
-	s.orderedDiffIDList = parsedConfig.RootFS.DiffIDs
-	s.knownLayers = knownLayers
-	return nil
-}
-
-// loadTarManifest loads and decodes the manifest.json.
-func (s *daemonImageSource) 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
-	if err := json.Unmarshal(bytes, &items); err != nil {
-		return nil, errors.Wrap(err, "Error decoding tar manifest.json")
-	}
-	if len(items) != 1 {
-		return nil, errors.Errorf("Unexpected tar manifest.json: expected 1 item, got %d", len(items))
-	}
-	return &items[0], nil
-}
-
-func (s *daemonImageSource) prepareLayerData(tarManifest *manifestItem, parsedConfig *dockerImage) (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))
-	}
-	knownLayers := map[diffID]*layerInfo{}
-	unknownLayerSizes := map[string]*layerInfo{} // Points into knownLayers, a "to do list" of items with unknown sizes.
-	for i, diffID := range parsedConfig.RootFS.DiffIDs {
-		if _, ok := knownLayers[diffID]; ok {
-			// Apparently it really can happen that a single image contains the same layer diff more than once.
-			// In that case, the diffID validation ensures that both layers truly are the same, and it should not matter
-			// which of the tarManifest.Layers paths is used; (docker save) actually makes the duplicates symlinks to the original.
-			continue
-		}
-		layerPath := tarManifest.Layers[i]
-		if _, ok := unknownLayerSizes[layerPath]; ok {
-			return nil, errors.Errorf("Layer tarfile %s used for two different DiffID values", layerPath)
-		}
-		li := &layerInfo{ // A new element in each iteration
-			path: layerPath,
-			size: -1,
-		}
-		knownLayers[diffID] = li
-		unknownLayerSizes[layerPath] = li
-	}
-
-	// Scan the tar file to collect layer sizes.
-	file, err := os.Open(s.tarCopyPath)
-	if err != nil {
-		return nil, err
-	}
-	defer file.Close()
-	t := tar.NewReader(file)
-	for {
-		h, err := t.Next()
-		if err == io.EOF {
-			break
-		}
-		if err != nil {
-			return nil, err
-		}
-		if li, ok := unknownLayerSizes[h.Name]; ok {
-			li.size = h.Size
-			delete(unknownLayerSizes, h.Name)
-		}
-	}
-	if len(unknownLayerSizes) != 0 {
-		return nil, errors.Errorf("Some layer tarfiles are missing in the tarball") // This could do with a better error reporting, if this ever happened in practice.
-	}
-
-	return knownLayers, nil
-}
-
-// GetManifest returns the image's manifest along with its MIME type (which may be empty when it can't be determined but the manifest is available).
-// It may use a remote (= slow) service.
-func (s *daemonImageSource) GetManifest() ([]byte, string, error) {
-	if s.generatedManifest == nil {
-		if err := s.ensureCachedDataIsPresent(); err != nil {
-			return nil, "", err
-		}
-		m := schema2Manifest{
-			SchemaVersion: 2,
-			MediaType:     manifest.DockerV2Schema2MediaType,
-			Config: distributionDescriptor{
-				MediaType: manifest.DockerV2Schema2ConfigMediaType,
-				Size:      int64(len(s.configBytes)),
-				Digest:    s.configDigest,
-			},
-			Layers: []distributionDescriptor{},
-		}
-		for _, diffID := range s.orderedDiffIDList {
-			li, ok := s.knownLayers[diffID]
-			if !ok {
-				return nil, "", errors.Errorf("Internal inconsistency: Information about layer %s missing", diffID)
-			}
-			m.Layers = append(m.Layers, distributionDescriptor{
-				Digest:    digest.Digest(diffID), // diffID is a digest of the uncompressed tarball
-				MediaType: manifest.DockerV2Schema2LayerMediaType,
-				Size:      li.size,
-			})
-		}
-		manifestBytes, err := json.Marshal(&m)
-		if err != nil {
-			return nil, "", err
-		}
-		s.generatedManifest = manifestBytes
-	}
-	return s.generatedManifest, manifest.DockerV2Schema2MediaType, nil
-}
-
-// GetTargetManifest returns an image's manifest given a digest. This is mainly used to retrieve a single image's manifest
-// out of a manifest list.
-func (s *daemonImageSource) GetTargetManifest(digest digest.Digest) ([]byte, string, error) {
-	// How did we even get here? GetManifest() above has returned a manifest.DockerV2Schema2MediaType.
-	return nil, "", errors.Errorf(`Manifest lists are not supported by "docker-daemon:"`)
-}
-
-type readCloseWrapper struct {
-	io.Reader
-	closeFunc func() error
-}
-
-func (r readCloseWrapper) Close() error {
-	if r.closeFunc != nil {
-		return r.closeFunc()
-	}
-	return nil
-}
-
-// GetBlob returns a stream for the specified blob, and the blob’s size (or -1 if unknown).
-func (s *daemonImageSource) GetBlob(info types.BlobInfo) (io.ReadCloser, int64, error) {
-	if err := s.ensureCachedDataIsPresent(); err != nil {
-		return nil, 0, err
-	}
-
-	if info.Digest == s.configDigest { // FIXME? Implement a more general algorithm matching instead of assuming sha256.
-		return ioutil.NopCloser(bytes.NewReader(s.configBytes)), int64(len(s.configBytes)), nil
-	}
-
-	if li, ok := s.knownLayers[diffID(info.Digest)]; ok { // diffID is a digest of the uncompressed tarball,
-		stream, err := s.openTarComponent(li.path)
-		if err != nil {
-			return nil, 0, err
-		}
-
-		// In order to handle the fact that digests != diffIDs (and thus that a
-		// caller which is trying to verify the blob will run into problems),
-		// we need to decompress blobs. This is a bit ugly, but it's a
-		// consequence of making everything addressable by their DiffID rather
-		// than by their digest...
-		//
-		// In particular, because the v2s2 manifest being generated uses
-		// DiffIDs, any caller of GetBlob is going to be asking for DiffIDs of
-		// layers not their _actual_ digest. The result is that copy/... will
-		// be verifing a "digest" which is not the actual layer's digest (but
-		// is instead the DiffID).
-
-		decompressFunc, reader, err := compression.DetectCompression(stream)
-		if err != nil {
-			return nil, 0, errors.Wrapf(err, "Detecting compression in blob %s", info.Digest)
-		}
-
-		if decompressFunc != nil {
-			reader, err = decompressFunc(reader)
-			if err != nil {
-				return nil, 0, errors.Wrapf(err, "Decompressing blob %s stream", info.Digest)
-			}
-		}
-
-		newStream := readCloseWrapper{
-			Reader:    reader,
-			closeFunc: stream.Close,
-		}
-
-		return newStream, li.size, nil
-	}
-
-	return nil, 0, errors.Errorf("Unknown blob %s", info.Digest)
-}
-
-// GetSignatures returns the image's signatures.  It may use a remote (= slow) service.
-func (s *daemonImageSource) GetSignatures() ([][]byte, error) {
-	return [][]byte{}, nil
-}

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

@@ -0,0 +1,250 @@
+package tarfile
+
+import (
+	"archive/tar"
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"time"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/containers/image/docker/reference"
+	"github.com/containers/image/manifest"
+	"github.com/containers/image/types"
+	"github.com/opencontainers/go-digest"
+	"github.com/pkg/errors"
+)
+
+const temporaryDirectoryForBigFiles = "/var/tmp" // Do not use the system default of os.TempDir(), usually /tmp, because with systemd it could be a tmpfs.
+
+// Destination is a partial implementation of types.ImageDestination for writing to an io.Writer.
+type Destination struct {
+	writer  io.Writer
+	tar     *tar.Writer
+	repoTag string
+	// Other state.
+	blobs map[digest.Digest]types.BlobInfo // list of already-sent blobs
+}
+
+// NewDestination returns a tarfile.Destination for the specified io.Writer.
+func NewDestination(dest io.Writer, ref reference.NamedTagged) *Destination {
+	// For github.com/docker/docker consumers, this works just as well as
+	//   refString := ref.String()
+	// because when reading the RepoTags strings, github.com/docker/docker/reference
+	// normalizes both of them to the same value.
+	//
+	// Doing it this way to include the normalized-out `docker.io[/library]` does make
+	// a difference for github.com/projectatomic/docker consumers, with the
+	// “Add --add-registry and --block-registry options to docker daemon” patch.
+	// These consumers treat reference strings which include a hostname and reference
+	// strings without a hostname differently.
+	//
+	// Using the host name here is more explicit about the intent, and it has the same
+	// effect as (docker pull) in projectatomic/docker, which tags the result using
+	// a hostname-qualified reference.
+	// See https://github.com/containers/image/issues/72 for a more detailed
+	// analysis and explanation.
+	refString := fmt.Sprintf("%s:%s", ref.Name(), ref.Tag())
+	return &Destination{
+		writer:  dest,
+		tar:     tar.NewWriter(dest),
+		repoTag: refString,
+		blobs:   make(map[digest.Digest]types.BlobInfo),
+	}
+}
+
+// SupportedManifestMIMETypes tells which manifest mime types the destination supports
+// If an empty slice or nil it's returned, then any mime type can be tried to upload
+func (d *Destination) SupportedManifestMIMETypes() []string {
+	return []string{
+		manifest.DockerV2Schema2MediaType, // We rely on the types.Image.UpdatedImage schema conversion capabilities.
+	}
+}
+
+// SupportsSignatures returns an error (to be displayed to the user) if the destination certainly can't store signatures.
+// Note: It is still possible for PutSignatures to fail if SupportsSignatures returns nil.
+func (d *Destination) SupportsSignatures() error {
+	return errors.Errorf("Storing signatures for docker tar files is not supported")
+}
+
+// ShouldCompressLayers returns true iff it is desirable to compress layer blobs written to this destination.
+func (d *Destination) ShouldCompressLayers() bool {
+	return false
+}
+
+// AcceptsForeignLayerURLs returns false iff foreign layers in manifest should be actually
+// uploaded to the image destination, true otherwise.
+func (d *Destination) AcceptsForeignLayerURLs() 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.
+// WARNING: The contents of stream are being verified on the fly.  Until stream.Read() returns io.EOF, the contents of the data SHOULD NOT be available
+// to any other readers for download using the supplied digest.
+// If stream.Read() at any time, ESPECIALLY at end of input, returns an error, PutBlob MUST 1) fail, and 2) delete any data stored so far.
+func (d *Destination) PutBlob(stream io.Reader, inputInfo types.BlobInfo) (types.BlobInfo, error) {
+	if inputInfo.Digest.String() == "" {
+		return types.BlobInfo{}, errors.Errorf("Can not stream a blob with unknown digest to docker tarfile")
+	}
+
+	ok, size, err := d.HasBlob(inputInfo)
+	if err != nil {
+		return types.BlobInfo{}, err
+	}
+	if ok {
+		return types.BlobInfo{Digest: inputInfo.Digest, Size: size}, nil
+	}
+
+	if inputInfo.Size == -1 { // Ouch, we need to stream the blob into a temporary file just to determine the size.
+		logrus.Debugf("docker tarfile: input with unknown size, streaming to disk first ...")
+		streamCopy, err := ioutil.TempFile(temporaryDirectoryForBigFiles, "docker-tarfile-blob")
+		if err != nil {
+			return types.BlobInfo{}, err
+		}
+		defer os.Remove(streamCopy.Name())
+		defer streamCopy.Close()
+
+		size, err := io.Copy(streamCopy, stream)
+		if err != nil {
+			return types.BlobInfo{}, err
+		}
+		_, err = streamCopy.Seek(0, os.SEEK_SET)
+		if err != nil {
+			return types.BlobInfo{}, err
+		}
+		inputInfo.Size = size // inputInfo is a struct, so we are only modifying our copy.
+		stream = streamCopy
+		logrus.Debugf("... streaming done")
+	}
+
+	digester := digest.Canonical.Digester()
+	tee := io.TeeReader(stream, digester.Hash())
+	if err := d.sendFile(inputInfo.Digest.String(), inputInfo.Size, tee); err != nil {
+		return types.BlobInfo{}, err
+	}
+	d.blobs[inputInfo.Digest] = types.BlobInfo{Digest: digester.Digest(), Size: inputInfo.Size}
+	return types.BlobInfo{Digest: digester.Digest(), Size: inputInfo.Size}, nil
+}
+
+// HasBlob returns true iff the image destination already contains a blob with
+// the matching digest which can be reapplied using ReapplyBlob.  Unlike
+// PutBlob, the digest can not be empty.  If HasBlob returns true, the size of
+// the blob must also be returned.  If the destination does not contain the
+// blob, or it is unknown, HasBlob ordinarily returns (false, -1, nil); it
+// returns a non-nil error only on an unexpected failure.
+func (d *Destination) HasBlob(info types.BlobInfo) (bool, int64, error) {
+	if info.Digest == "" {
+		return false, -1, errors.Errorf("Can not check for a blob with unknown digest")
+	}
+	if blob, ok := d.blobs[info.Digest]; ok {
+		return true, blob.Size, nil
+	}
+	return false, -1, nil
+}
+
+// ReapplyBlob informs the image destination that a blob for which HasBlob
+// previously returned true would have been passed to PutBlob if it had
+// returned false.  Like HasBlob and unlike PutBlob, the digest can not be
+// empty.  If the blob is a filesystem layer, this signifies that the changes
+// it describes need to be applied again when composing a filesystem tree.
+func (d *Destination) ReapplyBlob(info types.BlobInfo) (types.BlobInfo, error) {
+	return info, nil
+}
+
+// PutManifest sends the given manifest blob to the destination.
+// FIXME? This should also receive a MIME type if known, to differentiate
+//        between schema versions.
+func (d *Destination) PutManifest(m []byte) error {
+	var man schema2Manifest
+	if err := json.Unmarshal(m, &man); err != nil {
+		return errors.Wrap(err, "Error parsing manifest")
+	}
+	if man.SchemaVersion != 2 || man.MediaType != manifest.DockerV2Schema2MediaType {
+		return errors.Errorf("Unsupported manifest type, need a Docker schema 2 manifest")
+	}
+
+	layerPaths := []string{}
+	for _, l := range man.Layers {
+		layerPaths = append(layerPaths, l.Digest.String())
+	}
+
+	items := []manifestItem{{
+		Config:       man.Config.Digest.String(),
+		RepoTags:     []string{d.repoTag},
+		Layers:       layerPaths,
+		Parent:       "",
+		LayerSources: nil,
+	}}
+	itemsBytes, err := json.Marshal(&items)
+	if err != nil {
+		return err
+	}
+
+	// FIXME? Do we also need to support the legacy format?
+	return d.sendFile(manifestFileName, int64(len(itemsBytes)), bytes.NewReader(itemsBytes))
+}
+
+type tarFI struct {
+	path string
+	size int64
+}
+
+func (t *tarFI) Name() string {
+	return t.path
+}
+func (t *tarFI) Size() int64 {
+	return t.size
+}
+func (t *tarFI) Mode() os.FileMode {
+	return 0444
+}
+func (t *tarFI) ModTime() time.Time {
+	return time.Unix(0, 0)
+}
+func (t *tarFI) IsDir() bool {
+	return false
+}
+func (t *tarFI) Sys() interface{} {
+	return nil
+}
+
+// sendFile sends a file into the tar stream.
+func (d *Destination) sendFile(path string, expectedSize int64, stream io.Reader) error {
+	hdr, err := tar.FileInfoHeader(&tarFI{path: path, size: expectedSize}, "")
+	if err != nil {
+		return nil
+	}
+	logrus.Debugf("Sending as tar file %s", path)
+	if err := d.tar.WriteHeader(hdr); err != nil {
+		return err
+	}
+	size, err := io.Copy(d.tar, stream)
+	if err != nil {
+		return err
+	}
+	if size != expectedSize {
+		return errors.Errorf("Size mismatch when copying %s, expected %d, got %d", path, expectedSize, size)
+	}
+	return nil
+}
+
+// PutSignatures adds the given signatures to the docker tarfile (currently not
+// supported). MUST be called after PutManifest (signatures reference manifest
+// contents)
+func (d *Destination) PutSignatures(signatures [][]byte) error {
+	if len(signatures) != 0 {
+		return errors.Errorf("Storing signatures for docker tar files is not supported")
+	}
+	return nil
+}
+
+// Commit finishes writing data to the underlying io.Writer.
+// It is the caller's responsibility to close it, if necessary.
+func (d *Destination) Commit() error {
+	return d.tar.Close()
+}

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

@@ -0,0 +1,3 @@
+// Package tarfile is an internal implementation detail of some transports.
+// Do not use outside of the github.com/containers/image repo!
+package tarfile

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

@@ -0,0 +1,352 @@
+package tarfile
+
+import (
+	"archive/tar"
+	"bytes"
+	"encoding/json"
+	"io"
+	"io/ioutil"
+	"os"
+	"path"
+
+	"github.com/containers/image/manifest"
+	"github.com/containers/image/pkg/compression"
+	"github.com/containers/image/types"
+	"github.com/opencontainers/go-digest"
+	"github.com/pkg/errors"
+)
+
+// Source is a partial implementation of types.ImageSource for reading from tarPath.
+type Source struct {
+	tarPath string
+	// The following data is only available after ensureCachedDataIsPresent() succeeds
+	tarManifest       *manifestItem // nil if not available yet.
+	configBytes       []byte
+	configDigest      digest.Digest
+	orderedDiffIDList []diffID
+	knownLayers       map[diffID]*layerInfo
+	// Other state
+	generatedManifest []byte // Private cache for GetManifest(), nil if not set yet.
+}
+
+type layerInfo struct {
+	path string
+	size int64
+}
+
+// NewSource returns a tarfile.Source for the specified path.
+func NewSource(path string) *Source {
+	// TODO: We could add support for multiple images in a single archive, so
+	//       that people could use docker-archive:opensuse.tar:opensuse:leap as
+	//       the source of an image.
+	return &Source{
+		tarPath: path,
+	}
+}
+
+// tarReadCloser is a way to close the backing file of a tar.Reader when the user no longer needs the tar component.
+type tarReadCloser struct {
+	*tar.Reader
+	backingFile *os.File
+}
+
+func (t *tarReadCloser) Close() error {
+	return t.backingFile.Close()
+}
+
+// openTarComponent returns a ReadCloser for the specific file within the archive.
+// This is linear scan; we assume that the tar file will have a fairly small amount of files (~layers),
+// and that filesystem caching will make the repeated seeking over the (uncompressed) tarPath cheap enough.
+// The caller should call .Close() on the returned stream.
+func (s *Source) openTarComponent(componentPath string) (io.ReadCloser, error) {
+	f, err := os.Open(s.tarPath)
+	if err != nil {
+		return nil, err
+	}
+	succeeded := false
+	defer func() {
+		if !succeeded {
+			f.Close()
+		}
+	}()
+
+	tarReader, header, err := findTarComponent(f, componentPath)
+	if err != nil {
+		return nil, err
+	}
+	if header == nil {
+		return nil, os.ErrNotExist
+	}
+	if header.FileInfo().Mode()&os.ModeType == os.ModeSymlink { // FIXME: untested
+		// We follow only one symlink; so no loops are possible.
+		if _, err := f.Seek(0, os.SEEK_SET); err != nil {
+			return nil, err
+		}
+		// The new path could easily point "outside" the archive, but we only compare it to existing tar headers without extracting the archive,
+		// so we don't care.
+		tarReader, header, err = findTarComponent(f, path.Join(path.Dir(componentPath), header.Linkname))
+		if err != nil {
+			return nil, err
+		}
+		if header == nil {
+			return nil, os.ErrNotExist
+		}
+	}
+
+	if !header.FileInfo().Mode().IsRegular() {
+		return nil, errors.Errorf("Error reading tar archive component %s: not a regular file", header.Name)
+	}
+	succeeded = true
+	return &tarReadCloser{Reader: tarReader, backingFile: f}, nil
+}
+
+// findTarComponent returns a header and a reader matching path within inputFile,
+// or (nil, nil, nil) if not found.
+func findTarComponent(inputFile io.Reader, path string) (*tar.Reader, *tar.Header, error) {
+	t := tar.NewReader(inputFile)
+	for {
+		h, err := t.Next()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return nil, nil, err
+		}
+		if h.Name == path {
+			return t, h, nil
+		}
+	}
+	return nil, nil, nil
+}
+
+// readTarComponent returns full contents of componentPath.
+func (s *Source) readTarComponent(path string) ([]byte, error) {
+	file, err := s.openTarComponent(path)
+	if err != nil {
+		return nil, errors.Wrapf(err, "Error loading tar component %s", path)
+	}
+	defer file.Close()
+	bytes, err := ioutil.ReadAll(file)
+	if err != nil {
+		return nil, err
+	}
+	return bytes, nil
+}
+
+// ensureCachedDataIsPresent loads data necessary for any of the public accessors.
+func (s *Source) ensureCachedDataIsPresent() error {
+	if s.tarManifest != nil {
+		return nil
+	}
+
+	// Read and parse manifest.json
+	tarManifest, err := s.loadTarManifest()
+	if err != nil {
+		return err
+	}
+
+	// Read and parse config.
+	configBytes, err := s.readTarComponent(tarManifest.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)
+	}
+
+	knownLayers, err := s.prepareLayerData(tarManifest, &parsedConfig)
+	if err != nil {
+		return err
+	}
+
+	// Success; commit.
+	s.tarManifest = tarManifest
+	s.configBytes = configBytes
+	s.configDigest = digest.FromBytes(configBytes)
+	s.orderedDiffIDList = parsedConfig.RootFS.DiffIDs
+	s.knownLayers = knownLayers
+	return nil
+}
+
+// loadTarManifest loads and decodes the manifest.json.
+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
+	if err := json.Unmarshal(bytes, &items); err != nil {
+		return nil, errors.Wrap(err, "Error decoding tar manifest.json")
+	}
+	if len(items) != 1 {
+		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) {
+	// 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))
+	}
+	knownLayers := map[diffID]*layerInfo{}
+	unknownLayerSizes := map[string]*layerInfo{} // Points into knownLayers, a "to do list" of items with unknown sizes.
+	for i, diffID := range parsedConfig.RootFS.DiffIDs {
+		if _, ok := knownLayers[diffID]; ok {
+			// Apparently it really can happen that a single image contains the same layer diff more than once.
+			// In that case, the diffID validation ensures that both layers truly are the same, and it should not matter
+			// which of the tarManifest.Layers paths is used; (docker save) actually makes the duplicates symlinks to the original.
+			continue
+		}
+		layerPath := tarManifest.Layers[i]
+		if _, ok := unknownLayerSizes[layerPath]; ok {
+			return nil, errors.Errorf("Layer tarfile %s used for two different DiffID values", layerPath)
+		}
+		li := &layerInfo{ // A new element in each iteration
+			path: layerPath,
+			size: -1,
+		}
+		knownLayers[diffID] = li
+		unknownLayerSizes[layerPath] = li
+	}
+
+	// Scan the tar file to collect layer sizes.
+	file, err := os.Open(s.tarPath)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+	t := tar.NewReader(file)
+	for {
+		h, err := t.Next()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return nil, err
+		}
+		if li, ok := unknownLayerSizes[h.Name]; ok {
+			li.size = h.Size
+			delete(unknownLayerSizes, h.Name)
+		}
+	}
+	if len(unknownLayerSizes) != 0 {
+		return nil, errors.Errorf("Some layer tarfiles are missing in the tarball") // This could do with a better error reporting, if this ever happened in practice.
+	}
+
+	return knownLayers, nil
+}
+
+// GetManifest returns the image's manifest along with its MIME type (which may be empty when it can't be determined but the manifest is available).
+// It may use a remote (= slow) service.
+func (s *Source) GetManifest() ([]byte, string, error) {
+	if s.generatedManifest == nil {
+		if err := s.ensureCachedDataIsPresent(); err != nil {
+			return nil, "", err
+		}
+		m := schema2Manifest{
+			SchemaVersion: 2,
+			MediaType:     manifest.DockerV2Schema2MediaType,
+			Config: distributionDescriptor{
+				MediaType: manifest.DockerV2Schema2ConfigMediaType,
+				Size:      int64(len(s.configBytes)),
+				Digest:    s.configDigest,
+			},
+			Layers: []distributionDescriptor{},
+		}
+		for _, diffID := range s.orderedDiffIDList {
+			li, ok := s.knownLayers[diffID]
+			if !ok {
+				return nil, "", errors.Errorf("Internal inconsistency: Information about layer %s missing", diffID)
+			}
+			m.Layers = append(m.Layers, distributionDescriptor{
+				Digest:    digest.Digest(diffID), // diffID is a digest of the uncompressed tarball
+				MediaType: manifest.DockerV2Schema2LayerMediaType,
+				Size:      li.size,
+			})
+		}
+		manifestBytes, err := json.Marshal(&m)
+		if err != nil {
+			return nil, "", err
+		}
+		s.generatedManifest = manifestBytes
+	}
+	return s.generatedManifest, manifest.DockerV2Schema2MediaType, nil
+}
+
+// GetTargetManifest returns an image's manifest given a digest. This is mainly used to retrieve a single image's manifest
+// out of a manifest list.
+func (s *Source) GetTargetManifest(digest digest.Digest) ([]byte, string, error) {
+	// How did we even get here? GetManifest() above has returned a manifest.DockerV2Schema2MediaType.
+	return nil, "", errors.Errorf(`Manifest lists are not supported by "docker-daemon:"`)
+}
+
+type readCloseWrapper struct {
+	io.Reader
+	closeFunc func() error
+}
+
+func (r readCloseWrapper) Close() error {
+	if r.closeFunc != nil {
+		return r.closeFunc()
+	}
+	return nil
+}
+
+// GetBlob returns a stream for the specified blob, and the blob’s size (or -1 if unknown).
+func (s *Source) GetBlob(info types.BlobInfo) (io.ReadCloser, int64, error) {
+	if err := s.ensureCachedDataIsPresent(); err != nil {
+		return nil, 0, err
+	}
+
+	if info.Digest == s.configDigest { // FIXME? Implement a more general algorithm matching instead of assuming sha256.
+		return ioutil.NopCloser(bytes.NewReader(s.configBytes)), int64(len(s.configBytes)), nil
+	}
+
+	if li, ok := s.knownLayers[diffID(info.Digest)]; ok { // diffID is a digest of the uncompressed tarball,
+		stream, err := s.openTarComponent(li.path)
+		if err != nil {
+			return nil, 0, err
+		}
+
+		// In order to handle the fact that digests != diffIDs (and thus that a
+		// caller which is trying to verify the blob will run into problems),
+		// we need to decompress blobs. This is a bit ugly, but it's a
+		// consequence of making everything addressable by their DiffID rather
+		// than by their digest...
+		//
+		// In particular, because the v2s2 manifest being generated uses
+		// DiffIDs, any caller of GetBlob is going to be asking for DiffIDs of
+		// layers not their _actual_ digest. The result is that copy/... will
+		// be verifing a "digest" which is not the actual layer's digest (but
+		// is instead the DiffID).
+
+		decompressFunc, reader, err := compression.DetectCompression(stream)
+		if err != nil {
+			return nil, 0, errors.Wrapf(err, "Detecting compression in blob %s", info.Digest)
+		}
+
+		if decompressFunc != nil {
+			reader, err = decompressFunc(reader)
+			if err != nil {
+				return nil, 0, errors.Wrapf(err, "Decompressing blob %s stream", info.Digest)
+			}
+		}
+
+		newStream := readCloseWrapper{
+			Reader:    reader,
+			closeFunc: stream.Close,
+		}
+
+		return newStream, li.size, nil
+	}
+
+	return nil, 0, errors.Errorf("Unknown blob %s", info.Digest)
+}
+
+// GetSignatures returns the image's signatures.  It may use a remote (= slow) service.
+func (s *Source) GetSignatures() ([][]byte, error) {
+	return [][]byte{}, nil
+}

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

@@ -1,4 +1,4 @@
-package daemon
+package tarfile
 
 import "github.com/opencontainers/go-digest"
 
@@ -43,7 +43,7 @@ type schema2Manifest struct {
 
 // Based on github.com/docker/docker/image/image.go
 // MOST CONTENT OMITTED AS UNNECESSARY
-type dockerImage struct {
+type image struct {
 	RootFS *rootFS `json:"rootfs,omitempty"`
 }
 

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

@@ -4,8 +4,8 @@ import (
 	"time"
 
 	"github.com/containers/image/manifest"
+	"github.com/containers/image/pkg/strslice"
 	"github.com/containers/image/types"
-	"github.com/docker/docker/api/types/strslice"
 	"github.com/opencontainers/go-digest"
 	imgspecv1 "github.com/opencontainers/image-spec/specs-go/v1"
 )

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

@@ -0,0 +1 @@
+This package was replicated from [github.com/docker/docker v17.04.0-ce](https://github.com/docker/docker/tree/v17.04.0-ce/api/types/strslice).

vendor/github.com/containers/image/pkg/strslice/strslice.go

@@ -0,0 +1,30 @@
+package strslice
+
+import "encoding/json"
+
+// StrSlice represents a string or an array of strings.
+// We need to override the json decoder to accept both options.
+type StrSlice []string
+
+// UnmarshalJSON decodes the byte slice whether it's a string or an array of
+// strings. This method is needed to implement json.Unmarshaler.
+func (e *StrSlice) UnmarshalJSON(b []byte) error {
+	if len(b) == 0 {
+		// With no input, we preserve the existing value by returning nil and
+		// leaving the target alone. This allows defining default values for
+		// the type.
+		return nil
+	}
+
+	p := make([]string, 0, 1)
+	if err := json.Unmarshal(b, &p); err != nil {
+		var s string
+		if err := json.Unmarshal(b, &s); err != nil {
+			return err
+		}
+		p = append(p, s)
+	}
+
+	*e = p
+	return nil
+}

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

@@ -8,6 +8,7 @@ import (
 	// a transport.
 	_ "github.com/containers/image/directory"
 	_ "github.com/containers/image/docker"
+	_ "github.com/containers/image/docker/archive"
 	_ "github.com/containers/image/docker/daemon"
 	_ "github.com/containers/image/oci/layout"
 	_ "github.com/containers/image/openshift"

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

@@ -0,0 +1,31 @@
+github.com/Sirupsen/logrus 7f4b1adc791766938c29457bed0703fb9134421a
+github.com/containers/storage 5cbbc6bafb45bd7ef10486b673deb3b81bb3b787
+github.com/davecgh/go-spew 346938d642f2ec3594ed81d874461961cd0faa76
+github.com/docker/distribution df5327f76fb6468b84a87771e361762b8be23fdb
+github.com/docker/docker 75843d36aa5c3eaade50da005f9e0ff2602f3d5e
+github.com/docker/go-connections 7da10c8c50cad14494ec818dcdfb6506265c0086
+github.com/docker/go-units 0dadbb0345b35ec7ef35e228dabb8de89a65bf52
+github.com/docker/libtrust aabc10ec26b754e797f9028f4589c5b7bd90dc20
+github.com/ghodss/yaml 04f313413ffd65ce25f2541bfd2b2ceec5c0908c
+github.com/gorilla/context 08b5f424b9271eedf6f9f0ce86cb9396ed337a42
+github.com/gorilla/mux 94e7d24fd285520f3d12ae998f7fdd6b5393d453
+github.com/imdario/mergo 50d4dbd4eb0e84778abe37cefef140271d96fade
+github.com/mattn/go-runewidth 14207d285c6c197daabb5c9793d63e7af9ab2d50
+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-rc4
+github.com/opencontainers/runc 6b1d0e76f239ffb435445e5ae316d2676c07c6e3
+github.com/pborman/uuid 1b00554d822231195d1babd97ff4a781231955c9
+github.com/pkg/errors 248dadf4e9068a0b3e79f02ed0a610d935de5302
+github.com/pmezard/go-difflib 792786c7400a136282c1664665ae0a8db921c6c2
+github.com/stretchr/testify 4d4bfba8f1d1027c4fdbe371823030df51419987
+github.com/vbatts/tar-split bd4c5d64c3e9297f410025a3b1bd0c58f659e721
+golang.org/x/crypto 453249f01cfeb54c3d549ddb75ff152ca243f9d8
+golang.org/x/net 6b27048ae5e6ad1ef927e72e437531493de612fe
+golang.org/x/sys 075e574b89e4c2d22f2286a7e2b919519c6f3547
+gopkg.in/cheggaaa/pb.v1 d7e6ca3010b6f084d8056847f55d7f572f180678
+gopkg.in/yaml.v2 a3f3340b5840cee44f372bddb5880fcbc419b46a
+k8s.io/client-go bcde30fb7eaed76fd98a36b4120321b94995ffb6
+github.com/xeipuuv/gojsonschema master