Use ocischema package instead of custom handler

Previously we were re-using schema2.DeserializedManifest to handle oci
manifests. The issue lies in the fact that distribution started
validating the media type string during json deserialization. This
change broke our usage of that type.

Instead distribution now provides direct support for oci schemas, so use
that instead of our custom handlers.

Signed-off-by: Brian Goff <cpuguy83@gmail.com>
(cherry picked from commit e443512ce4799380941374ef64fc30edc989650e)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Upstream-commit: e037bade8cac920cc2927c194c77778ddd041101
Component: engine

Author: cpuguy83

components/engine/distribution/oci.go

@@ -14,6 +14,7 @@ import (
 	"github.com/containerd/containerd/platforms"
 	"github.com/docker/distribution"
 	"github.com/docker/distribution/manifest/manifestlist"
+	"github.com/docker/distribution/manifest/ocischema"
 	"github.com/docker/distribution/manifest/schema1"
 	"github.com/docker/distribution/manifest/schema2"
 	"github.com/docker/distribution/reference"
@@ -410,6 +411,11 @@ func (p *v2Puller) pullV2Tag(ctx context.Context, ref reference.Named, platform
 		if err != nil {
 			return false, err
 		}
+	case *ocischema.DeserializedManifest:
+		id, manifestDigest, err = p.pullOCI(ctx, ref, v, platform)
+		if err != nil {
+			return false, err
+		}
 	case *manifestlist.DeserializedManifestList:
 		id, manifestDigest, err = p.pullManifestList(ctx, ref, v, platform)
 		if err != nil {
@@ -557,24 +563,18 @@ func (p *v2Puller) pullSchema1(ctx context.Context, ref reference.Reference, unv
 	return imageID, manifestDigest, nil
 }
 
-func (p *v2Puller) pullSchema2(ctx context.Context, ref reference.Named, mfst *schema2.DeserializedManifest, platform *specs.Platform) (id digest.Digest, manifestDigest digest.Digest, err error) {
-	manifestDigest, err = schema2ManifestDigest(ref, mfst)
-	if err != nil {
-		return "", "", err
-	}
-
-	target := mfst.Target()
+func (p *v2Puller) pullSchema2Layers(ctx context.Context, target distribution.Descriptor, layers []distribution.Descriptor, platform *specs.Platform) (id digest.Digest, err error) {
 	if _, err := p.config.ImageStore.Get(target.Digest); err == nil {
 		// If the image already exists locally, no need to pull
 		// anything.
-		return target.Digest, manifestDigest, nil
+		return target.Digest, nil
 	}
 
 	var descriptors []xfer.DownloadDescriptor
 
 	// Note that the order of this loop is in the direction of bottom-most
 	// to top-most, so that the downloads slice gets ordered correctly.
-	for _, d := range mfst.Layers {
+	for _, d := range layers {
 		layerDescriptor := &v2LayerDescriptor{
 			digest:            d.Digest,
 			repo:              p.repo,
@@ -629,23 +629,23 @@ func (p *v2Puller) pullSchema2(ctx context.Context, ref reference.Named, mfst *s
 	if runtime.GOOS == "windows" {
 		configJSON, configRootFS, configPlatform, err = receiveConfig(p.config.ImageStore, configChan, configErrChan)
 		if err != nil {
-			return "", "", err
+			return "", err
 		}
 		if configRootFS == nil {
-			return "", "", errRootFSInvalid
+			return "", errRootFSInvalid
 		}
 		if err := checkImageCompatibility(configPlatform.OS, configPlatform.OSVersion); err != nil {
-			return "", "", err
+			return "", err
 		}
 
 		if len(descriptors) != len(configRootFS.DiffIDs) {
-			return "", "", errRootFSMismatch
+			return "", errRootFSMismatch
 		}
 		if platform == nil {
 			// Early bath if the requested OS doesn't match that of the configuration.
 			// This avoids doing the download, only to potentially fail later.
 			if !system.IsOSSupported(configPlatform.OS) {
-				return "", "", fmt.Errorf("cannot download image with operating system %q when requesting %q", configPlatform.OS, layerStoreOS)
+				return "", fmt.Errorf("cannot download image with operating system %q when requesting %q", configPlatform.OS, layerStoreOS)
 			}
 			layerStoreOS = configPlatform.OS
 		}
@@ -692,14 +692,14 @@ func (p *v2Puller) pullSchema2(ctx context.Context, ref reference.Named, mfst *s
 			case <-downloadsDone:
 			case <-layerErrChan:
 			}
-			return "", "", err
+			return "", err
 		}
 	}
 
 	select {
 	case <-downloadsDone:
 	case err = <-layerErrChan:
-		return "", "", err
+		return "", err
 	}
 
 	if release != nil {
@@ -711,22 +711,40 @@ func (p *v2Puller) pullSchema2(ctx context.Context, ref reference.Named, mfst *s
 		// Otherwise the image config could be referencing layers that aren't
 		// included in the manifest.
 		if len(downloadedRootFS.DiffIDs) != len(configRootFS.DiffIDs) {
-			return "", "", errRootFSMismatch
+			return "", errRootFSMismatch
 		}
 
 		for i := range downloadedRootFS.DiffIDs {
 			if downloadedRootFS.DiffIDs[i] != configRootFS.DiffIDs[i] {
-				return "", "", errRootFSMismatch
+				return "", errRootFSMismatch
 			}
 		}
 	}
 
 	imageID, err := p.config.ImageStore.Put(configJSON)
+	if err != nil {
+		return "", err
+	}
+
+	return imageID, nil
+}
+
+func (p *v2Puller) pullSchema2(ctx context.Context, ref reference.Named, mfst *schema2.DeserializedManifest, platform *specs.Platform) (id digest.Digest, manifestDigest digest.Digest, err error) {
+	manifestDigest, err = schema2ManifestDigest(ref, mfst)
 	if err != nil {
 		return "", "", err
 	}
+	id, err = p.pullSchema2Layers(ctx, mfst.Target(), mfst.Layers, platform)
+	return id, manifestDigest, err
+}
 
-	return imageID, manifestDigest, nil
+func (p *v2Puller) pullOCI(ctx context.Context, ref reference.Named, mfst *ocischema.DeserializedManifest, platform *specs.Platform) (id digest.Digest, manifestDigest digest.Digest, err error) {
+	manifestDigest, err = schema2ManifestDigest(ref, mfst)
+	if err != nil {
+		return "", "", err
+	}
+	id, err = p.pullSchema2Layers(ctx, mfst.Target(), mfst.Layers, platform)
+	return id, manifestDigest, err
 }
 
 func receiveConfig(s ImageConfigStore, configChan <-chan []byte, errChan <-chan error) ([]byte, *image.RootFS, *specs.Platform, error) {
@@ -811,6 +829,12 @@ func (p *v2Puller) pullManifestList(ctx context.Context, ref reference.Named, mf
 		if err != nil {
 			return "", "", err
 		}
+	case *ocischema.DeserializedManifest:
+		platform := toOCIPlatform(manifestMatches[0].Platform)
+		id, _, err = p.pullOCI(ctx, manifestRef, v, &platform)
+		if err != nil {
+			return "", "", err
+		}
 	default:
 		return "", "", errors.New("unsupported manifest format")
 	}