Update for changed images.Type API

cmd/skopeo/copy.go

@@ -26,24 +26,24 @@ func copyHandler(context *cli.Context) error {
 	}
 	signBy := context.String("sign-by")
 
-	manifest, err := src.Manifest()
+	manifest, _, err := src.Manifest()
 	if err != nil {
 		return fmt.Errorf("Error reading manifest: %v", err)
 	}
 
-	layers, err := src.LayerDigests()
+	blobDigests, err := src.BlobDigests()
 	if err != nil {
 		return fmt.Errorf("Error parsing manifest: %v", err)
 	}
-	for _, layer := range layers {
+	for _, digest := range blobDigests {
 		// TODO(mitr): do not ignore the size param returned here
-		stream, _, err := rawSource.GetBlob(layer)
+		stream, _, err := rawSource.GetBlob(digest)
 		if err != nil {
-			return fmt.Errorf("Error reading layer %s: %v", layer, err)
+			return fmt.Errorf("Error reading blob %s: %v", digest, err)
 		}
 		defer stream.Close()
-		if err := dest.PutBlob(layer, stream); err != nil {
-			return fmt.Errorf("Error writing layer: %v", err)
+		if err := dest.PutBlob(digest, stream); err != nil {
+			return fmt.Errorf("Error writing blob: %v", err)
 		}
 	}
 

cmd/skopeo/inspect.go

@@ -38,7 +38,7 @@ var inspectCmd = cli.Command{
 		if err != nil {
 			return err
 		}
-		rawManifest, err := img.Manifest()
+		rawManifest, _, err := img.Manifest()
 		if err != nil {
 			return err
 		}

cmd/skopeo/layers.go

@@ -19,35 +19,35 @@ var layersCmd = cli.Command{
 			return err
 		}
 		src := image.FromSource(rawSource)
-		layers := c.Args().Tail()
-		if len(layers) == 0 {
-			ls, err := src.LayerDigests()
+		blobDigests := c.Args().Tail()
+		if len(blobDigests) == 0 {
+			b, err := src.BlobDigests()
 			if err != nil {
 				return err
 			}
-			layers = ls
+			blobDigests = b
 		}
 		tmpDir, err := ioutil.TempDir(".", "layers-")
 		if err != nil {
 			return err
 		}
 		dest := directory.NewDirImageDestination(tmpDir)
-		manifest, err := src.Manifest()
+		manifest, _, err := src.Manifest()
 		if err != nil {
 			return err
 		}
 		if err := dest.PutManifest(manifest); err != nil {
 			return err
 		}
-		for _, l := range layers {
-			if !strings.HasPrefix(l, "sha256:") {
-				l = "sha256:" + l
+		for _, digest := range blobDigests {
+			if !strings.HasPrefix(digest, "sha256:") {
+				digest = "sha256:" + digest
 			}
-			r, _, err := rawSource.GetBlob(l)
+			r, _, err := rawSource.GetBlob(digest)
 			if err != nil {
 				return err
 			}
-			if err := dest.PutBlob(l, r); err != nil {
+			if err := dest.PutBlob(digest, r); err != nil {
 				r.Close()
 				return err
 			}

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

@@ -2,13 +2,8 @@ package directory
 
 import (
 	"fmt"
-	"io"
-	"io/ioutil"
-	"os"
 	"path/filepath"
 	"strings"
-
-	"github.com/containers/image/types"
 )
 
 // manifestPath returns a path for the manifest within a directory using our conventions.
@@ -16,110 +11,13 @@ func manifestPath(dir string) string {
 	return filepath.Join(dir, "manifest.json")
 }
 
-// manifestPath returns a path for a layer tarball within a directory using our conventions.
+// layerPath returns a path for a layer tarball within a directory using our conventions.
 func layerPath(dir string, digest string) string {
 	// FIXME: Should we keep the digest identification?
 	return filepath.Join(dir, strings.TrimPrefix(digest, "sha256:")+".tar")
 }
 
-// manifestPath returns a path for a signature within a directory using our conventions.
+// signaturePath returns a path for a signature within a directory using our conventions.
 func signaturePath(dir string, index int) string {
 	return filepath.Join(dir, fmt.Sprintf("signature-%d", index+1))
 }
-
-type dirImageDestination struct {
-	dir string
-}
-
-// NewDirImageDestination returns an ImageDestination for writing to an existing directory.
-func NewDirImageDestination(dir string) types.ImageDestination {
-	return &dirImageDestination{dir}
-}
-
-func (d *dirImageDestination) CanonicalDockerReference() (string, error) {
-	return "", fmt.Errorf("Can not determine canonical Docker reference for a local directory")
-}
-
-func (d *dirImageDestination) PutManifest(manifest []byte) error {
-	return ioutil.WriteFile(manifestPath(d.dir), manifest, 0644)
-}
-
-func (d *dirImageDestination) PutBlob(digest string, stream io.Reader) error {
-	layerFile, err := os.Create(layerPath(d.dir, digest))
-	if err != nil {
-		return err
-	}
-	defer layerFile.Close()
-	if _, err := io.Copy(layerFile, stream); err != nil {
-		return err
-	}
-	if err := layerFile.Sync(); err != nil {
-		return err
-	}
-	return nil
-}
-
-func (d *dirImageDestination) PutSignatures(signatures [][]byte) error {
-	for i, sig := range signatures {
-		if err := ioutil.WriteFile(signaturePath(d.dir, i), sig, 0644); err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
-type dirImageSource struct {
-	dir string
-}
-
-// NewDirImageSource returns an ImageSource reading from an existing directory.
-func NewDirImageSource(dir string) types.ImageSource {
-	return &dirImageSource{dir}
-}
-
-// IntendedDockerReference returns the full, unambiguous, Docker reference for this image, _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.
-// May be "" if unknown.
-func (s *dirImageSource) IntendedDockerReference() string {
-	return ""
-}
-
-// it's up to the caller to determine the MIME type of the returned manifest's bytes
-func (s *dirImageSource) GetManifest(_ []string) ([]byte, string, error) {
-	m, err := ioutil.ReadFile(manifestPath(s.dir))
-	if err != nil {
-		return nil, "", err
-	}
-	return m, "", err
-}
-
-func (s *dirImageSource) GetBlob(digest string) (io.ReadCloser, int64, error) {
-	r, err := os.Open(layerPath(s.dir, digest))
-	if err != nil {
-		return nil, 0, nil
-	}
-	fi, err := os.Stat(layerPath(s.dir, digest))
-	if err != nil {
-		return nil, 0, nil
-	}
-	return r, fi.Size(), nil
-}
-
-func (s *dirImageSource) GetSignatures() ([][]byte, error) {
-	signatures := [][]byte{}
-	for i := 0; ; i++ {
-		signature, err := ioutil.ReadFile(signaturePath(s.dir, i))
-		if err != nil {
-			if os.IsNotExist(err) {
-				break
-			}
-			return nil, err
-		}
-		signatures = append(signatures, signature)
-	}
-	return signatures, nil
-}
-
-func (s *dirImageSource) Delete() error {
-	return fmt.Errorf("directory#dirImageSource.Delete() not implmented")
-}

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

@@ -0,0 +1,51 @@
+package directory
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+
+	"github.com/containers/image/types"
+)
+
+type dirImageDestination struct {
+	dir string
+}
+
+// NewDirImageDestination returns an ImageDestination for writing to an existing directory.
+func NewDirImageDestination(dir string) types.ImageDestination {
+	return &dirImageDestination{dir}
+}
+
+func (d *dirImageDestination) CanonicalDockerReference() (string, error) {
+	return "", fmt.Errorf("Can not determine canonical Docker reference for a local directory")
+}
+
+func (d *dirImageDestination) PutManifest(manifest []byte) error {
+	return ioutil.WriteFile(manifestPath(d.dir), manifest, 0644)
+}
+
+func (d *dirImageDestination) PutBlob(digest string, stream io.Reader) error {
+	layerFile, err := os.Create(layerPath(d.dir, digest))
+	if err != nil {
+		return err
+	}
+	defer layerFile.Close()
+	if _, err := io.Copy(layerFile, stream); err != nil {
+		return err
+	}
+	if err := layerFile.Sync(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (d *dirImageDestination) PutSignatures(signatures [][]byte) error {
+	for i, sig := range signatures {
+		if err := ioutil.WriteFile(signaturePath(d.dir, i), sig, 0644); err != nil {
+			return err
+		}
+	}
+	return nil
+}

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

@@ -0,0 +1,66 @@
+package directory
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+
+	"github.com/containers/image/types"
+)
+
+type dirImageSource struct {
+	dir string
+}
+
+// NewDirImageSource returns an ImageSource reading from an existing directory.
+func NewDirImageSource(dir string) types.ImageSource {
+	return &dirImageSource{dir}
+}
+
+// IntendedDockerReference returns the full, unambiguous, Docker reference for this image, _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.
+// May be "" if unknown.
+func (s *dirImageSource) IntendedDockerReference() string {
+	return ""
+}
+
+// it's up to the caller to determine the MIME type of the returned manifest's bytes
+func (s *dirImageSource) GetManifest(_ []string) ([]byte, string, error) {
+	m, err := ioutil.ReadFile(manifestPath(s.dir))
+	if err != nil {
+		return nil, "", err
+	}
+	return m, "", err
+}
+
+func (s *dirImageSource) GetBlob(digest string) (io.ReadCloser, int64, error) {
+	r, err := os.Open(layerPath(s.dir, digest))
+	if err != nil {
+		return nil, 0, nil
+	}
+	fi, err := os.Stat(layerPath(s.dir, digest))
+	if err != nil {
+		return nil, 0, nil
+	}
+	return r, fi.Size(), nil
+}
+
+func (s *dirImageSource) GetSignatures() ([][]byte, error) {
+	signatures := [][]byte{}
+	for i := 0; ; i++ {
+		signature, err := ioutil.ReadFile(signaturePath(s.dir, i))
+		if err != nil {
+			if os.IsNotExist(err) {
+				break
+			}
+			return nil, err
+		}
+		signatures = append(signatures, signature)
+	}
+	return signatures, nil
+}
+
+func (s *dirImageSource) Delete() error {
+	return fmt.Errorf("directory#dirImageSource.Delete() not implmented")
+}

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

@@ -4,12 +4,13 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
+	"mime"
 	"net/http"
 	"strconv"
 
 	"github.com/Sirupsen/logrus"
-	"github.com/containers/image/manifest"
 	"github.com/containers/image/docker/reference"
+	"github.com/containers/image/manifest"
 	"github.com/containers/image/types"
 )
 
@@ -57,6 +58,19 @@ func (s *dockerImageSource) IntendedDockerReference() string {
 	return fmt.Sprintf("%s:%s", s.ref.Name(), s.tag)
 }
 
+// simplifyContentType drops parameters from a HTTP media type (see https://tools.ietf.org/html/rfc7231#section-3.1.1.1)
+// Alternatively, an empty string is returned unchanged, and invalid values are "simplified" to an empty string.
+func simplifyContentType(contentType string) string {
+	if contentType == "" {
+		return contentType
+	}
+	mimeType, _, err := mime.ParseMediaType(contentType)
+	if err != nil {
+		return ""
+	}
+	return mimeType
+}
+
 func (s *dockerImageSource) GetManifest(mimetypes []string) ([]byte, string, error) {
 	url := fmt.Sprintf(manifestURL, s.ref.RemoteName(), s.tag)
 	// TODO(runcom) set manifest version header! schema1 for now - then schema2 etc etc and v1
@@ -76,7 +90,7 @@ func (s *dockerImageSource) GetManifest(mimetypes []string) ([]byte, string, err
 		return nil, "", errFetchManifest{res.StatusCode, manblob}
 	}
 	// We might validate manblob against the Docker-Content-Digest header here to protect against transport errors.
-	return manblob, res.Header.Get("Content-Type"), nil
+	return manblob, simplifyContentType(res.Header.Get("Content-Type")), nil
 }
 
 func (s *dockerImageSource) GetBlob(digest string) (io.ReadCloser, int64, error) {

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

@@ -7,6 +7,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"io/ioutil"
 	"regexp"
 	"time"
 
@@ -24,9 +25,15 @@ var (
 // may not be a `genericImage` directly. However, most users of `types.Image`
 // do not care, and those who care about `skopeo/docker.Image` know they do.
 type genericImage struct {
-	src              types.ImageSource
-	cachedManifest   []byte   // Private cache for Manifest(); nil if not yet known.
-	cachedSignatures [][]byte // Private cache for Signatures(); nil if not yet known.
+	src types.ImageSource
+	// private cache for Manifest(); nil if not yet known.
+	cachedManifest []byte
+	// private cache for the manifest media type w/o having to guess it
+	// this may be the empty string in case the MIME Type wasn't guessed correctly
+	// this field is valid only if cachedManifest is not nil
+	cachedManifestMIMEType string
+	// private cache for Signatures(); nil if not yet known.
+	cachedSignatures [][]byte
 }
 
 // FromSource returns a types.Image implementation for source.
@@ -42,16 +49,20 @@ func (i *genericImage) IntendedDockerReference() string {
 }
 
 // Manifest is like ImageSource.GetManifest, but the result is cached; it is OK to call this however often you need.
-// NOTE: It is essential for signature verification that Manifest returns the manifest from which LayerDigests is computed.
-func (i *genericImage) Manifest() ([]byte, error) {
+// NOTE: It is essential for signature verification that Manifest returns the manifest from which BlobDigests is computed.
+func (i *genericImage) Manifest() ([]byte, string, error) {
 	if i.cachedManifest == nil {
-		m, _, err := i.src.GetManifest([]string{manifest.DockerV2Schema1MIMEType})
+		m, mt, err := i.src.GetManifest([]string{manifest.DockerV2Schema1SignedMIMEType, manifest.DockerV2Schema1MIMEType})
 		if err != nil {
-			return nil, err
+			return nil, "", err
 		}
 		i.cachedManifest = m
+		if mt == "" {
+			mt = manifest.GuessMIMEType(i.cachedManifest)
+		}
+		i.cachedManifestMIMEType = mt
 	}
-	return i.cachedManifest, nil
+	return i.cachedManifest, i.cachedManifestMIMEType, nil
 }
 
 // Signatures is like ImageSource.GetSignatures, but the result is cached; it is OK to call this however often you need.
@@ -68,27 +79,11 @@ func (i *genericImage) Signatures() ([][]byte, error) {
 
 func (i *genericImage) Inspect() (*types.ImageInspectInfo, error) {
 	// TODO(runcom): unused version param for now, default to docker v2-1
-	m, err := i.getSchema1Manifest()
+	m, err := i.getParsedManifest()
 	if err != nil {
 		return nil, err
 	}
-	ms1, ok := m.(*manifestSchema1)
-	if !ok {
-		return nil, fmt.Errorf("error retrivieng manifest schema1")
-	}
-	v1 := &v1Image{}
-	if err := json.Unmarshal([]byte(ms1.History[0].V1Compatibility), v1); err != nil {
-		return nil, err
-	}
-	return &types.ImageInspectInfo{
-		Tag:           ms1.Tag,
-		DockerVersion: v1.DockerVersion,
-		Created:       v1.Created,
-		Labels:        v1.Config.Labels,
-		Architecture:  v1.Architecture,
-		Os:            v1.OS,
-		Layers:        ms1.GetLayers(),
-	}, nil
+	return m.ImageInspectInfo()
 }
 
 type config struct {
@@ -110,13 +105,19 @@ type v1Image struct {
 
 // will support v1 one day...
 type genericManifest interface {
-	GetLayers() []string
+	Config() ([]byte, error)
+	LayerDigests() []string
+	BlobDigests() []string
+	ImageInspectInfo() (*types.ImageInspectInfo, error)
 }
 
 type fsLayersSchema1 struct {
 	BlobSum string `json:"blobSum"`
 }
 
+// compile-time check that manifestSchema1 implements genericManifest
+var _ genericManifest = (*manifestSchema1)(nil)
+
 type manifestSchema1 struct {
 	Name     string
 	Tag      string
@@ -128,7 +129,7 @@ type manifestSchema1 struct {
 	//Signature []byte `json:"signature"`
 }
 
-func (m *manifestSchema1) GetLayers() []string {
+func (m *manifestSchema1) LayerDigests() []string {
 	layers := make([]string, len(m.FSLayers))
 	for i, layer := range m.FSLayers {
 		layers[i] = layer.BlobSum
@@ -136,38 +137,140 @@ func (m *manifestSchema1) GetLayers() []string {
 	return layers
 }
 
-// getSchema1Manifest parses the manifest into a data structure, cleans it up, and returns it.
-// NOTE: The manifest may have been modified in the process; DO NOT reserialize and store the return value
-// if you want to preserve the original manifest; use the blob returned by Manifest() directly.
-// NOTE: It is essential for signature verification that the object is computed from the same manifest which is returned by Manifest().
-func (i *genericImage) getSchema1Manifest() (genericManifest, error) {
-	manblob, err := i.Manifest()
+func (m *manifestSchema1) BlobDigests() []string {
+	return m.LayerDigests()
+}
+
+func (m *manifestSchema1) Config() ([]byte, error) {
+	return []byte(m.History[0].V1Compatibility), nil
+}
+
+func (m *manifestSchema1) ImageInspectInfo() (*types.ImageInspectInfo, error) {
+	v1 := &v1Image{}
+	config, err := m.Config()
 	if err != nil {
 		return nil, err
 	}
-	mschema1 := &manifestSchema1{}
-	if err := json.Unmarshal(manblob, mschema1); err != nil {
+	if err := json.Unmarshal(config, v1); err != nil {
 		return nil, err
 	}
-	if err := fixManifestLayers(mschema1); err != nil {
-		return nil, err
-	}
-	// TODO(runcom): verify manifest schema 1, 2 etc
-	//if len(m.FSLayers) != len(m.History) {
-	//return nil, fmt.Errorf("length of history not equal to number of layers for %q", ref.String())
-	//}
-	//if len(m.FSLayers) == 0 {
-	//return nil, fmt.Errorf("no FSLayers in manifest for %q", ref.String())
-	//}
-	return mschema1, nil
+	return &types.ImageInspectInfo{
+		Tag:           m.Tag,
+		DockerVersion: v1.DockerVersion,
+		Created:       v1.Created,
+		Labels:        v1.Config.Labels,
+		Architecture:  v1.Architecture,
+		Os:            v1.OS,
+		Layers:        m.LayerDigests(),
+	}, nil
 }
 
-// uniqueLayerDigests returns a list of layer digests referenced from a manifest.
+// compile-time check that manifestSchema2 implements genericManifest
+var _ genericManifest = (*manifestSchema2)(nil)
+
+type manifestSchema2 struct {
+	src               types.ImageSource
+	ConfigDescriptor  descriptor   `json:"config"`
+	LayersDescriptors []descriptor `json:"layers"`
+}
+
+type descriptor struct {
+	MediaType string `json:"mediaType"`
+	Size      int64  `json:"size"`
+	Digest    string `json:"digest"`
+}
+
+func (m *manifestSchema2) LayerDigests() []string {
+	blobs := []string{}
+	for _, layer := range m.LayersDescriptors {
+		blobs = append(blobs, layer.Digest)
+	}
+	return blobs
+}
+
+func (m *manifestSchema2) BlobDigests() []string {
+	blobs := m.LayerDigests()
+	blobs = append(blobs, m.ConfigDescriptor.Digest)
+	return blobs
+}
+
+func (m *manifestSchema2) Config() ([]byte, error) {
+	rawConfig, _, err := m.src.GetBlob(m.ConfigDescriptor.Digest)
+	if err != nil {
+		return nil, err
+	}
+	config, err := ioutil.ReadAll(rawConfig)
+	rawConfig.Close()
+	return config, err
+}
+
+func (m *manifestSchema2) ImageInspectInfo() (*types.ImageInspectInfo, error) {
+	config, err := m.Config()
+	if err != nil {
+		return nil, err
+	}
+	v1 := &v1Image{}
+	if err := json.Unmarshal(config, v1); err != nil {
+		return nil, err
+	}
+	return &types.ImageInspectInfo{
+		DockerVersion: v1.DockerVersion,
+		Created:       v1.Created,
+		Labels:        v1.Config.Labels,
+		Architecture:  v1.Architecture,
+		Os:            v1.OS,
+		Layers:        m.LayerDigests(),
+	}, nil
+}
+
+// getParsedManifest parses the manifest into a data structure, cleans it up, and returns it.
+// NOTE: The manifest may have been modified in the process; DO NOT reserialize and store the return value
+// if you want to preserve the original manifest; use the blob returned by Manifest() directly.
+// NOTE: It is essential for signature verification that the object is computed from the same manifest which is returned by Manifest().
+func (i *genericImage) getParsedManifest() (genericManifest, error) {
+	manblob, mt, err := i.Manifest()
+	if err != nil {
+		return nil, err
+	}
+	switch mt {
+	// "application/json" is a valid v2s1 value per https://github.com/docker/distribution/blob/master/docs/spec/manifest-v2-1.md .
+	// This works for now, when nothing else seems to return "application/json"; if that were not true, the mapping/detection might
+	// need to happen within the ImageSource.
+	case manifest.DockerV2Schema1MIMEType, manifest.DockerV2Schema1SignedMIMEType, "application/json":
+		mschema1 := &manifestSchema1{}
+		if err := json.Unmarshal(manblob, mschema1); err != nil {
+			return nil, err
+		}
+		if err := fixManifestLayers(mschema1); err != nil {
+			return nil, err
+		}
+		// TODO(runcom): verify manifest schema 1, 2 etc
+		//if len(m.FSLayers) != len(m.History) {
+		//return nil, fmt.Errorf("length of history not equal to number of layers for %q", ref.String())
+		//}
+		//if len(m.FSLayers) == 0 {
+		//return nil, fmt.Errorf("no FSLayers in manifest for %q", ref.String())
+		//}
+		return mschema1, nil
+	case manifest.DockerV2Schema2MIMEType:
+		v2s2 := manifestSchema2{src: i.src}
+		if err := json.Unmarshal(manblob, &v2s2); err != nil {
+			return nil, err
+		}
+		return &v2s2, nil
+	case "":
+		return nil, errors.New("could not guess manifest media type")
+	default:
+		return nil, fmt.Errorf("unsupported manifest media type %s", mt)
+	}
+}
+
+// uniqueBlobDigests returns a list of blob digests referenced from a manifest.
 // The list will not contain duplicates; it is not intended to correspond to the "history" or "parent chain" of a Docker image.
-func uniqueLayerDigests(m genericManifest) []string {
+func uniqueBlobDigests(m genericManifest) []string {
 	var res []string
 	seen := make(map[string]struct{})
-	for _, digest := range m.GetLayers() {
+	for _, digest := range m.BlobDigests() {
 		if _, ok := seen[digest]; ok {
 			continue
 		}
@@ -177,15 +280,15 @@ func uniqueLayerDigests(m genericManifest) []string {
 	return res
 }
 
-// LayerDigests returns a list of layer digests referenced by this image.
+// BlobDigests returns a list of blob digests referenced by this image.
 // The list will not contain duplicates; it is not intended to correspond to the "history" or "parent chain" of a Docker image.
-// NOTE: It is essential for signature verification that LayerDigests is computed from the same manifest which is returned by Manifest().
-func (i *genericImage) LayerDigests() ([]string, error) {
-	m, err := i.getSchema1Manifest()
+// NOTE: It is essential for signature verification that BlobDigests is computed from the same manifest which is returned by Manifest().
+func (i *genericImage) BlobDigests() ([]string, error) {
+	m, err := i.getParsedManifest()
 	if err != nil {
 		return nil, err
 	}
-	return uniqueLayerDigests(m), nil
+	return uniqueBlobDigests(m), nil
 }
 
 func (i *genericImage) getLayer(dest types.ImageDestination, digest string) error {

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

@@ -14,11 +14,12 @@ import (
 const (
 	// DockerV2Schema1MIMEType MIME type represents Docker manifest schema 1
 	DockerV2Schema1MIMEType = "application/vnd.docker.distribution.manifest.v1+json"
+	// DockerV2Schema1MIMEType MIME type represents Docker manifest schema 1 with a JWS signature
+	DockerV2Schema1SignedMIMEType = "application/vnd.docker.distribution.manifest.v1+prettyjws"
 	// DockerV2Schema2MIMEType MIME type represents Docker manifest schema 2
 	DockerV2Schema2MIMEType = "application/vnd.docker.distribution.manifest.v2+json"
 	// DockerV2ListMIMEType MIME type represents Docker manifest schema 2 list
 	DockerV2ListMIMEType = "application/vnd.docker.distribution.manifest.list.v2+json"
-
 	// OCIV1DescriptorMIMEType TODO
 	OCIV1DescriptorMIMEType = "application/vnd.oci.descriptor.v1+json"
 	// OCIV1ImageManifestMIMEType TODO
@@ -40,8 +41,9 @@ func GuessMIMEType(manifest []byte) string {
 	// A subset of manifest fields; the rest is silently ignored by json.Unmarshal.
 	// Also docker/distribution/manifest.Versioned.
 	meta := struct {
-		MediaType     string `json:"mediaType"`
-		SchemaVersion int    `json:"schemaVersion"`
+		MediaType     string      `json:"mediaType"`
+		SchemaVersion int         `json:"schemaVersion"`
+		Signatures    interface{} `json:"signatures"`
 	}{}
 	if err := json.Unmarshal(manifest, &meta); err != nil {
 		return ""
@@ -54,6 +56,9 @@ func GuessMIMEType(manifest []byte) string {
 	// this is the only way the function can return DockerV2Schema1MIMEType, and recognizing that is essential for stripping the JWS signatures = computing the correct manifest digest.
 	switch meta.SchemaVersion {
 	case 1:
+		if meta.Signatures != nil {
+			return DockerV2Schema1SignedMIMEType
+		}
 		return DockerV2Schema1MIMEType
 	case 2: // Really should not happen, meta.MediaType should have been set. But given the data, this is our best guess.
 		return DockerV2Schema2MIMEType
@@ -63,7 +68,7 @@ func GuessMIMEType(manifest []byte) string {
 
 // Digest returns the a digest of a docker manifest, with any necessary implied transformations like stripping v1s1 signatures.
 func Digest(manifest []byte) (string, error) {
-	if GuessMIMEType(manifest) == DockerV2Schema1MIMEType {
+	if GuessMIMEType(manifest) == DockerV2Schema1SignedMIMEType {
 		sig, err := libtrust.ParsePrettySignature(manifest, "signatures")
 		if err != nil {
 			return "", err

vendor/github.com/containers/image/signature/policy_eval_signedby.go

@@ -76,7 +76,7 @@ func (pr *prSignedBy) isSignatureAuthorAccepted(image types.Image, sig []byte) (
 			return nil
 		},
 		validateSignedDockerManifestDigest: func(digest string) error {
-			m, err := image.Manifest()
+			m, _, err := image.Manifest()
 			if err != nil {
 				return err
 			}

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

@@ -44,19 +44,21 @@ type Image interface {
 	// May be "" if unknown.
 	IntendedDockerReference() string
 	// Manifest is like ImageSource.GetManifest, but the result is cached; it is OK to call this however often you need.
-	// NOTE: It is essential for signature verification that Manifest returns the manifest from which LayerDigests is computed.
-	Manifest() ([]byte, error)
+	// NOTE: It is essential for signature verification that Manifest returns the manifest from which BlobDigests is computed.
+	Manifest() ([]byte, string, error)
 	// Signatures is like ImageSource.GetSignatures, but the result is cached; it is OK to call this however often you need.
 	Signatures() ([][]byte, error)
-	// LayerDigests returns a list of layer digests referenced by this image.
+	// BlobDigests returns a list of blob digests referenced by this image.
 	// The list will not contain duplicates; it is not intended to correspond to the "history" or "parent chain" of a Docker image.
-	// NOTE: It is essential for signature verification that LayerDigests is computed from the same manifest which is returned by Manifest().
-	LayerDigests() ([]string, error)
+	// NOTE: It is essential for signature verification that BlobDigests is computed from the same manifest which is returned by Manifest().
+	BlobDigests() ([]string, error)
 	// Inspect returns various information for (skopeo inspect) parsed from the manifest and configuration.
 	Inspect() (*ImageInspectInfo, error)
 }
 
 // ImageInspectInfo is a set of metadata describing Docker images, primarily their manifest and configuration.
+// The Tag field is a legacy field which is here just for the Docker v2s1 manifest. It won't be supported
+// for other manifest types.
 type ImageInspectInfo struct {
 	Tag           string
 	Created       time.Time