containerd · dmcgowan · Oct 3, 2023 · Sep 27, 2023 · Sep 27, 2023 · Sep 27, 2023
diff --git a/container_opts.go b/container_opts.go
@@ -120,24 +120,24 @@ func WithImageConfigLabels(image Image) NewContainerOpts {
 		if err != nil {
 			return err
 		}
+		if !images.IsConfigType(ic.MediaType) {
+			return fmt.Errorf("unknown image config media type %s", ic.MediaType)
+		}
+
 		var (
 			ociimage v1.Image
 			config   v1.ImageConfig
 		)
-		switch ic.MediaType {
-		case v1.MediaTypeImageConfig, images.MediaTypeDockerSchema2Config:
-			p, err := content.ReadBlob(ctx, image.ContentStore(), ic)
-			if err != nil {
-				return err
-			}
+		p, err := content.ReadBlob(ctx, image.ContentStore(), ic)
+		if err != nil {
+			return err
+		}
 
-			if err := json.Unmarshal(p, &ociimage); err != nil {
-				return err
-			}
-			config = ociimage.Config
-		default:
-			return fmt.Errorf("unknown image config media type %s", ic.MediaType)
+		if err = json.Unmarshal(p, &ociimage); err != nil {
+			return err
 		}
+		config = ociimage.Config
+
 		c.Labels = config.Labels
 		return nil
 	}

diff --git a/integration/client/export_test.go b/integration/client/export_test.go
@@ -116,8 +116,7 @@ func TestExportDockerManifest(t *testing.T) {
 	// test single-platform export
 	var result ocispec.Descriptor
 	err = images.Walk(ctx, images.HandlerFunc(func(ctx context.Context, desc ocispec.Descriptor) ([]ocispec.Descriptor, error) {
-		switch desc.MediaType {
-		case images.MediaTypeDockerSchema2Manifest, ocispec.MediaTypeImageManifest:
+		if images.IsManifestType(desc.MediaType) {
 			p, err := content.ReadBlob(ctx, client.ContentStore(), desc)
 			if err != nil {
 				return nil, err
@@ -132,7 +131,7 @@ func TestExportDockerManifest(t *testing.T) {
 				result = desc
 			}
 			return nil, nil
-		case images.MediaTypeDockerSchema2ManifestList, ocispec.MediaTypeImageIndex:
+		} else if images.IsIndexType(desc.MediaType) {
 			p, err := content.ReadBlob(ctx, client.ContentStore(), desc)
 			if err != nil {
 				return nil, err

diff --git a/oci/spec_opts.go b/oci/spec_opts.go
@@ -376,26 +376,24 @@ func WithImageConfigArgs(image Image, args []string) SpecOpts {
 		if err != nil {
 			return err
 		}
+		if !images.IsConfigType(ic.MediaType) {
+			return fmt.Errorf("unknown image config media type %s", ic.MediaType)
+		}
+
 		var (
 			imageConfigBytes []byte
 			ociimage         v1.Image
 			config           v1.ImageConfig
 		)
-		switch ic.MediaType {
-		case v1.MediaTypeImageConfig, images.MediaTypeDockerSchema2Config:
-			var err error
-			imageConfigBytes, err = content.ReadBlob(ctx, image.ContentStore(), ic)
-			if err != nil {
-				return err
-			}
+		imageConfigBytes, err = content.ReadBlob(ctx, image.ContentStore(), ic)
+		if err != nil {
+			return err
+		}
 
-			if err := json.Unmarshal(imageConfigBytes, &ociimage); err != nil {
-				return err
-			}
-			config = ociimage.Config
-		default:
-			return fmt.Errorf("unknown image config media type %s", ic.MediaType)
+		if err = json.Unmarshal(imageConfigBytes, &ociimage); err != nil {
+			return err
 		}
+		config = ociimage.Config
 
 		appendOSMounts(s, ociimage.OS)
 		setProcess(s)

diff --git a/pkg/display/manifest_printer.go b/pkg/display/manifest_printer.go
@@ -135,8 +135,7 @@ func (p *ImageTreePrinter) printManifestTree(ctx context.Context, desc ocispec.D
 		return err
 	}
 
-	switch desc.MediaType {
-	case images.MediaTypeDockerSchema2Manifest, ocispec.MediaTypeImageManifest:
+	if images.IsManifestType(desc.MediaType) {
 		var manifest ocispec.Manifest
 		if err := json.Unmarshal(b, &manifest); err != nil {
 			return err
@@ -158,8 +157,7 @@ func (p *ImageTreePrinter) printManifestTree(ctx context.Context, desc ocispec.D
 			}
 			fmt.Fprintf(p.w, "%s%s @%s (%d bytes)\n", subprefix, manifest.Layers[i].MediaType, manifest.Layers[i].Digest, manifest.Layers[i].Size)
 		}
-
-	case images.MediaTypeDockerSchema2ManifestList, ocispec.MediaTypeImageIndex:
+	} else if images.IsIndexType(desc.MediaType) {
 		var idx ocispec.Index
 		if err := json.Unmarshal(b, &idx); err != nil {
 			return err

diff --git a/pkg/snapshotters/annotations.go b/pkg/snapshotters/annotations.go
@@ -55,8 +55,7 @@ func AppendInfoHandlerWrapper(ref string) func(f images.Handler) images.Handler
 			if err != nil {
 				return nil, err
 			}
-			switch desc.MediaType {
-			case ocispec.MediaTypeImageManifest, images.MediaTypeDockerSchema2Manifest:
+			if images.IsManifestType(desc.MediaType) {
 				for i := range children {
 					c := &children[i]
 					if images.IsLayerType(c.MediaType) {

diff --git a/pkg/transfer/local/pull.go b/pkg/transfer/local/pull.go
@@ -255,24 +255,22 @@ func (ts *localTransferService) pull(ctx context.Context, ir transfer.ImageFetch
 }
 
 func fetchHandler(ingester content.Ingester, fetcher remotes.Fetcher, pt *ProgressTracker) images.HandlerFunc {
-	return func(ctx context.Context, desc ocispec.Descriptor) (subdescs []ocispec.Descriptor, err error) {
+	return func(ctx context.Context, desc ocispec.Descriptor) ([]ocispec.Descriptor, error) {
 		ctx = log.WithLogger(ctx, log.G(ctx).WithFields(log.Fields{
 			"digest":    desc.Digest,
 			"mediatype": desc.MediaType,
 			"size":      desc.Size,
 		}))
 
-		switch desc.MediaType {
-		case images.MediaTypeDockerSchema1Manifest:
+		if desc.MediaType == images.MediaTypeDockerSchema1Manifest {
 			return nil, fmt.Errorf("%v not supported", desc.MediaType)
-		default:
-			err := remotes.Fetch(ctx, ingester, fetcher, desc)
-			if errdefs.IsAlreadyExists(err) {
-				pt.MarkExists(desc)
-				return nil, nil
-			}
-			return nil, err
 		}
+		err := remotes.Fetch(ctx, ingester, fetcher, desc)
+		if errdefs.IsAlreadyExists(err) {
+			pt.MarkExists(desc)
+			return nil, nil
+		}
+		return nil, err
 	}
 }
 

diff --git a/pkg/unpack/unpacker.go b/pkg/unpack/unpacker.go
@@ -179,8 +179,7 @@ func (u *Unpacker) Unpack(h images.Handler) images.Handler {
 			return children, err
 		}
 
-		switch desc.MediaType {
-		case images.MediaTypeDockerSchema2Manifest, ocispec.MediaTypeImageManifest:
+		if images.IsManifestType(desc.MediaType) {
 			var nonLayers []ocispec.Descriptor
 			var manifestLayers []ocispec.Descriptor
 			// Split layers from non-layers, layers will be handled after
@@ -203,7 +202,7 @@ func (u *Unpacker) Unpack(h images.Handler) images.Handler {
 			lock.Unlock()
 
 			children = nonLayers
-		case images.MediaTypeDockerSchema2Config, ocispec.MediaTypeImageConfig:
+		} else if images.IsConfigType(desc.MediaType) {
 			lock.Lock()
 			l := layers[desc.Digest]
 			lock.Unlock()

diff --git a/remotes/docker/converter.go b/remotes/docker/converter.go
@@ -41,9 +41,7 @@ const LegacyConfigMediaType = "application/octet-stream"
 // 1. original manifest will be deleted by next gc round.
 // 2. don't cover manifest list.
 func ConvertManifest(ctx context.Context, store content.Store, desc ocispec.Descriptor) (ocispec.Descriptor, error) {
-	if !(desc.MediaType == images.MediaTypeDockerSchema2Manifest ||
-		desc.MediaType == ocispec.MediaTypeImageManifest) {
-
+	if !images.IsManifestType(desc.MediaType) {
 		log.G(ctx).Warnf("do nothing for media type: %s", desc.MediaType)
 		return desc, nil
 	}

diff --git a/remotes/docker/fetcher.go b/remotes/docker/fetcher.go
@@ -94,10 +94,8 @@ func (r dockerFetcher) Fetch(ctx context.Context, desc ocispec.Descriptor) (io.R
 		}
 
 		// Try manifests endpoints for manifests types
-		switch desc.MediaType {
-		case images.MediaTypeDockerSchema2Manifest, images.MediaTypeDockerSchema2ManifestList,
-			images.MediaTypeDockerSchema1Manifest,
-			ocispec.MediaTypeImageManifest, ocispec.MediaTypeImageIndex:
+		if images.IsManifestType(desc.MediaType) || images.IsIndexType(desc.MediaType) ||
+			desc.MediaType == images.MediaTypeDockerSchema1Manifest {
 
 			var firstErr error
 			for _, host := range r.hosts {

diff --git a/remotes/docker/pusher.go b/remotes/docker/pusher.go
@@ -103,12 +103,10 @@ func (p dockerPusher) push(ctx context.Context, desc ocispec.Descriptor, ref str
 		host       = hosts[0]
 	)
 
-	switch desc.MediaType {
-	case images.MediaTypeDockerSchema2Manifest, images.MediaTypeDockerSchema2ManifestList,
-		ocispec.MediaTypeImageManifest, ocispec.MediaTypeImageIndex:
+	if images.IsManifestType(desc.MediaType) || images.IsIndexType(desc.MediaType) {
 		isManifest = true
 		existCheck = getManifestPath(p.object, desc.Digest)
-	default:
+	} else {
 		existCheck = []string{"blobs", desc.Digest.String()}
 	}
 

diff --git a/remotes/handlers.go b/remotes/handlers.go
@@ -71,17 +71,17 @@ func MakeRefKey(ctx context.Context, desc ocispec.Descriptor) string {
 		}
 	}
 
-	switch mt := desc.MediaType; {
-	case mt == images.MediaTypeDockerSchema2Manifest || mt == ocispec.MediaTypeImageManifest:
+	switch {
+	case images.IsManifestType(desc.MediaType):
 		return "manifest-" + key
-	case mt == images.MediaTypeDockerSchema2ManifestList || mt == ocispec.MediaTypeImageIndex:
+	case images.IsIndexType(desc.MediaType):
 		return "index-" + key
-	case images.IsLayerType(mt):
+	case images.IsLayerType(desc.MediaType):
 		return "layer-" + key
-	case images.IsKnownConfig(mt):
+	case images.IsKnownConfig(desc.MediaType):
 		return "config-" + key
 	default:
-		log.G(ctx).Warnf("reference for unknown type: %s", mt)
+		log.G(ctx).Warnf("reference for unknown type: %s", desc.MediaType)
 		return "unknown-" + key
 	}
 }
@@ -90,23 +90,21 @@ func MakeRefKey(ctx context.Context, desc ocispec.Descriptor) string {
 // discovered in a call to Dispatch. Use with ChildrenHandler to do a full
 // recursive fetch.
 func FetchHandler(ingester content.Ingester, fetcher Fetcher) images.HandlerFunc {
-	return func(ctx context.Context, desc ocispec.Descriptor) (subdescs []ocispec.Descriptor, err error) {
+	return func(ctx context.Context, desc ocispec.Descriptor) ([]ocispec.Descriptor, error) {
 		ctx = log.WithLogger(ctx, log.G(ctx).WithFields(log.Fields{
 			"digest":    desc.Digest,
 			"mediatype": desc.MediaType,
 			"size":      desc.Size,
 		}))
 
-		switch desc.MediaType {
-		case images.MediaTypeDockerSchema1Manifest:
+		if desc.MediaType == images.MediaTypeDockerSchema1Manifest {
 			return nil, fmt.Errorf("%v not supported", desc.MediaType)
-		default:
-			err := Fetch(ctx, ingester, fetcher, desc)
-			if errdefs.IsAlreadyExists(err) {
-				return nil, nil
-			}
-			return nil, err
 		}
+		err := Fetch(ctx, ingester, fetcher, desc)
+		if errdefs.IsAlreadyExists(err) {
+			return nil, nil
+		}
+		return nil, err
 	}
 }
 
@@ -214,20 +212,18 @@ func PushContent(ctx context.Context, pusher Pusher, desc ocispec.Descriptor, st
 	indexStack := []ocispec.Descriptor{}
 
 	filterHandler := images.HandlerFunc(func(ctx context.Context, desc ocispec.Descriptor) ([]ocispec.Descriptor, error) {
-		switch desc.MediaType {
-		case images.MediaTypeDockerSchema2Manifest, ocispec.MediaTypeImageManifest:
+		if images.IsManifestType(desc.MediaType) {
 			m.Lock()
 			manifests = append(manifests, desc)
 			m.Unlock()
 			return nil, images.ErrStopHandler
-		case images.MediaTypeDockerSchema2ManifestList, ocispec.MediaTypeImageIndex:
+		} else if images.IsIndexType(desc.MediaType) {
 			m.Lock()
 			indexStack = append(indexStack, desc)
 			m.Unlock()
 			return nil, images.ErrStopHandler
-		default:
-			return nil, nil
 		}
+		return nil, nil
 	})
 
 	pushHandler := PushHandler(pusher, store)
@@ -318,24 +314,16 @@ func FilterManifestByPlatformHandler(f images.HandlerFunc, m platforms.Matcher)
 			return children, nil
 		}
 
-		var descs []ocispec.Descriptor
-		switch desc.MediaType {
-		case images.MediaTypeDockerSchema2Manifest, ocispec.MediaTypeImageManifest:
-			if m.Match(*desc.Platform) {
-				descs = children
-			} else {
-				for _, child := range children {
-					if child.MediaType == images.MediaTypeDockerSchema2Config ||
-						child.MediaType == ocispec.MediaTypeImageConfig {
-
-						descs = append(descs, child)
-					}
+		if images.IsManifestType(desc.MediaType) && !m.Match(*desc.Platform) {
+			var descs []ocispec.Descriptor
+			for _, child := range children {
+				if images.IsConfigType(child.MediaType) {
+					descs = append(descs, child)
 				}
 			}
-		default:
-			descs = children
+			return descs, nil
 		}
-		return descs, nil
+		return children, nil
 	}
 }
 
@@ -350,10 +338,7 @@ func annotateDistributionSourceHandler(f images.HandlerFunc, provider content.In
 
 		// Distribution source is only used for config or blob but may be inherited from
 		// a manifest or manifest list
-		switch desc.MediaType {
-		case images.MediaTypeDockerSchema2Manifest, ocispec.MediaTypeImageManifest,
-			images.MediaTypeDockerSchema2ManifestList, ocispec.MediaTypeImageIndex:
-		default:
+		if !images.IsManifestType(desc.MediaType) && !images.IsIndexType(desc.MediaType) {
 			return children, nil
 		}
 

diff --git a/signals.go b/signals.go
@@ -57,24 +57,23 @@ func GetOCIStopSignal(ctx context.Context, image Image, defaultSignal string) (s
 	if err != nil {
 		return "", err
 	}
+	if !images.IsConfigType(ic.MediaType) {
+		return "", fmt.Errorf("unknown image config media type %s", ic.MediaType)
+	}
+
 	var (
 		ociimage v1.Image
 		config   v1.ImageConfig
 	)
-	switch ic.MediaType {
-	case v1.MediaTypeImageConfig, images.MediaTypeDockerSchema2Config:
-		p, err := content.ReadBlob(ctx, image.ContentStore(), ic)
-		if err != nil {
-			return "", err
-		}
-
-		if err := json.Unmarshal(p, &ociimage); err != nil {
-			return "", err
-		}
-		config = ociimage.Config
-	default:
-		return "", fmt.Errorf("unknown image config media type %s", ic.MediaType)
+	p, err := content.ReadBlob(ctx, image.ContentStore(), ic)
+	if err != nil {
+		return "", err
+	}
+
+	if err = json.Unmarshal(p, &ociimage); err != nil {
+		return "", err
 	}
+	config = ociimage.Config
 
 	if config.StopSignal == "" {
 		return defaultSignal, nil