Correct missing sizes for manifest schema 1 images

Make sure to encode the updated sizes into image.DockerImageMetadata.Raw
otherwise the changes will be lost.

Signed-off-by: Michal Minář <miminar@redhat.com>

pkg/dockerregistry/server/manifestschema1handler.go

@@ -53,56 +53,75 @@ type manifestSchema1Handler struct {
 var _ ManifestHandler = &manifestSchema1Handler{}
 
 func (h *manifestSchema1Handler) FillImageMetadata(ctx context.Context, image *imageapiv1.Image) error {
-	signatures, err := h.manifest.Signatures()
-	if err != nil {
-		return err
+	// If we already have metadata don't mutate existing metadata.
+	meta, ok := image.DockerImageMetadata.Object.(*imageapi.DockerImage)
+	hasMetadata := ok && meta.Size > 0
+	if len(image.DockerImageLayers) > 0 && hasMetadata && len(image.DockerImageManifestMediaType) > 0 {
+		return nil
 	}
 
-	for _, signDigest := range signatures {
-		image.DockerImageSignatures = append(image.DockerImageSignatures, signDigest)
+	manifestData := image.DockerImageManifest
+	manifest := imageapi.DockerImageManifest{}
+	if err := json.Unmarshal([]byte(manifestData), &manifest); err != nil {
+		return err
 	}
 
-	refs := h.manifest.References()
+	image.DockerImageManifestMediaType = schema1.MediaTypeManifest
 
-	if err := imageMetadataFromManifest(image); err != nil {
-		return fmt.Errorf("unable to fill image %s metadata: %v", image.Name, err)
+	if len(manifest.History) == 0 {
+		// should never have an empty history, but just in case...
+		return nil
 	}
 
-	blobSet := sets.NewString()
-	meta, ok := image.DockerImageMetadata.Object.(*imageapi.DockerImage)
-	if !ok {
-		return fmt.Errorf("image %q does not have metadata", image.Name)
+	v1Metadata := imageapi.DockerV1CompatibilityImage{}
+	if err := json.Unmarshal([]byte(manifest.History[0].DockerV1Compatibility), &v1Metadata); err != nil {
+		return err
 	}
-	meta.Size = int64(0)
 
-	blobs := h.repo.Blobs(ctx)
-	for i := range image.DockerImageLayers {
-		layer := &image.DockerImageLayers[i]
-		// DockerImageLayers represents h.manifest.Manifest.FSLayers in reversed order
-		desc, err := blobs.Stat(ctx, refs[len(image.DockerImageLayers)-i-1].Digest)
-		if err != nil {
-			context.GetLogger(ctx).Errorf("failed to stat blob %s of image %s", layer.Name, image.DockerImageReference)
-			return err
-		}
-		// The MediaType appeared in manifest schema v2. We need to fill it
-		// manually in the old images if it is not already filled.
-		if len(layer.MediaType) == 0 {
-			if len(desc.MediaType) > 0 {
-				layer.MediaType = desc.MediaType
-			} else {
-				layer.MediaType = schema1.MediaTypeManifestLayer
+	var (
+		dockerImageSize int64
+		err             error
+		layerSet        = sets.NewString()
+		sizeContainer   = imageapi.DockerV1CompatibilityImageSize{}
+	)
+
+	image.DockerImageLayers = make([]imageapiv1.ImageLayer, len(manifest.FSLayers))
+	for hi, li := 0, len(manifest.FSLayers)-1; hi < len(manifest.FSLayers) && li >= 0; hi, li = hi+1, li-1 {
+		layer := &image.DockerImageLayers[li]
+		if hi == 0 { // the first item in history is v1Metadata
+			err = h.updateLayerMetadata(ctx, layer, &manifest.FSLayers[hi], v1Metadata.Size)
+		} else {
+			sizeContainer.Size = 0
+			if hi < len(manifest.History) {
+				if err := json.Unmarshal([]byte(manifest.History[hi].DockerV1Compatibility), &sizeContainer); err != nil {
+					sizeContainer.Size = 0
+				}
 			}
+			err = h.updateLayerMetadata(ctx, layer, &manifest.FSLayers[hi], sizeContainer.Size)
 		}
-		layer.LayerSize = desc.Size
+		if err != nil {
+			return fmt.Errorf("failed to update layer metadata of image %s: %v", image.DockerImageReference, err)
+		}
+
 		// count empty layer just once (empty layer may actually have non-zero size)
-		if !blobSet.Has(layer.Name) {
-			meta.Size += desc.Size
-			blobSet.Insert(layer.Name)
+		if !layerSet.Has(layer.Name) {
+			dockerImageSize += layer.LayerSize
+			layerSet.Insert(layer.Name)
 		}
 	}
-	image.DockerImageMetadata.Object = meta
 
-	return nil
+	signatures, err := h.manifest.Signatures()
+	if err != nil {
+		return err
+	}
+
+	for _, signDigest := range signatures {
+		image.DockerImageSignatures = append(image.DockerImageSignatures, signDigest)
+	}
+
+	image.DockerImageMetadata.Object = v1ToDockerImageMetadata(&v1Metadata, "", dockerImageSize)
+
+	return encodeRawDockerImageMetadata(image, true)
 }
 
 func (h *manifestSchema1Handler) Manifest() distribution.Manifest {
@@ -187,3 +206,20 @@ func (h *manifestSchema1Handler) Verify(ctx context.Context, skipDependencyVerif
 func (h *manifestSchema1Handler) Digest() (digest.Digest, error) {
 	return digest.FromBytes(h.manifest.Canonical), nil
 }
+
+func (h *manifestSchema1Handler) updateLayerMetadata(ctx context.Context, layer *imageapiv1.ImageLayer, manifestLayer *imageapi.DockerFSLayer, size int64) error {
+	layer.Name = manifestLayer.DockerBlobSum
+	layer.MediaType = schema1.MediaTypeManifestLayer
+	if size > 0 {
+		layer.LayerSize = size
+		return nil
+	}
+
+	desc, err := h.repo.Blobs(ctx).Stat(ctx, digest.Digest(layer.Name))
+	if err != nil {
+		context.GetLogger(ctx).Errorf("failed to stat blob %s", layer.Name)
+		return err
+	}
+	layer.LayerSize = desc.Size
+	return nil
+}