c8d/handlers: Handle error in walkPresentChildren

Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>

daemon/containerd/handlers.go

@@ -9,16 +9,13 @@ import (
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 )
 
-// walkPresentChildren is a simple wrapper for containerdimages.Walk with
-// presentChildrenHandler wrapping a simple handler that only operates on
-// walked Descriptor and doesn't return any errror.
+// walkPresentChildren is a simple wrapper for containerdimages.Walk with presentChildrenHandler.
 // This is only a convenient helper to reduce boilerplate.
-func (i *ImageService) walkPresentChildren(ctx context.Context, target ocispec.Descriptor, f func(context.Context, ocispec.Descriptor)) error {
+func (i *ImageService) walkPresentChildren(ctx context.Context, target ocispec.Descriptor, f func(context.Context, ocispec.Descriptor) error) error {
 	store := i.client.ContentStore()
 	return containerdimages.Walk(ctx, presentChildrenHandler(store, containerdimages.HandlerFunc(
 		func(ctx context.Context, desc ocispec.Descriptor) ([]ocispec.Descriptor, error) {
-			f(ctx, desc)
-			return nil, nil
+			return nil, f(ctx, desc)
 		})), target)
 }
 

daemon/containerd/image_delete.go

@@ -124,10 +124,11 @@ func (i *ImageService) deleteAll(ctx context.Context, img images.Image, force, p
 
 	// Workaround for: https://github.com/moby/buildkit/issues/3797
 	possiblyDeletedConfigs := map[digest.Digest]struct{}{}
-	err := i.walkPresentChildren(ctx, img.Target, func(_ context.Context, d ocispec.Descriptor) {
+	err := i.walkPresentChildren(ctx, img.Target, func(_ context.Context, d ocispec.Descriptor) error {
 		if images.IsConfigType(d.MediaType) {
 			possiblyDeletedConfigs[d.Digest] = struct{}{}
 		}
+		return nil
 	})
 	if err != nil {
 		return nil, err

daemon/containerd/image_manifest.go

@@ -15,6 +15,11 @@ import (
 	"github.com/pkg/errors"
 )
 
+var (
+	errNotManifestOrIndex = errdefs.InvalidParameter(errors.New("descriptor is neither a manifest or index"))
+	errNotManifest        = errdefs.InvalidParameter(errors.New("descriptor isn't a manifest"))
+)
+
 // walkImageManifests calls the handler for each locally present manifest in
 // the image. The image implements the containerd.Image interface, but all
 // operations act on the specific manifest instead of the index.
@@ -24,23 +29,23 @@ func (i *ImageService) walkImageManifests(ctx context.Context, img containerdima
 	handleManifest := func(ctx context.Context, d ocispec.Descriptor) error {
 		platformImg, err := i.NewImageManifest(ctx, img, d)
 		if err != nil {
+			if err == errNotManifest {
+				return nil
+			}
 			return err
 		}
 		return handler(platformImg)
 	}
 
+	if containerdimages.IsManifestType(desc.MediaType) {
+		return handleManifest(ctx, desc)
+	}
+
 	if containerdimages.IsIndexType(desc.MediaType) {
-		store := i.client.ContentStore()
-		return containerdimages.Walk(ctx, presentChildrenHandler(store, containerdimages.HandlerFunc(
-			func(ctx context.Context, desc ocispec.Descriptor) ([]ocispec.Descriptor, error) {
-				if containerdimages.IsManifestType(desc.MediaType) {
-					return nil, handleManifest(ctx, desc)
-				}
-				return nil, nil
-			})), desc)
+		return i.walkPresentChildren(ctx, desc, handleManifest)
 	}
 
-	return handleManifest(ctx, desc)
+	return errNotManifestOrIndex
 }
 
 type ImageManifest struct {
@@ -54,7 +59,7 @@ type ImageManifest struct {
 
 func (i *ImageService) NewImageManifest(ctx context.Context, img containerdimages.Image, manifestDesc ocispec.Descriptor) (*ImageManifest, error) {
 	if !containerdimages.IsManifestType(manifestDesc.MediaType) {
-		return nil, errdefs.InvalidParameter(errors.New("descriptor isn't a manifest"))
+		return nil, errNotManifest
 	}
 
 	parent := img.Target

daemon/containerd/image_prune.go

@@ -125,11 +125,12 @@ func (i *ImageService) pruneUnused(ctx context.Context, filterFunc imageFilterFu
 
 		blobs := []ocispec.Descriptor{}
 
-		err := i.walkPresentChildren(ctx, img.Target, func(_ context.Context, desc ocispec.Descriptor) {
+		err := i.walkPresentChildren(ctx, img.Target, func(_ context.Context, desc ocispec.Descriptor) error {
 			blobs = append(blobs, desc)
 			if containerdimages.IsConfigType(desc.MediaType) {
 				possiblyDeletedConfigs[desc.Digest] = struct{}{}
 			}
+			return nil
 		})
 		if err != nil {
 			errs = multierror.Append(errs, err)
@@ -186,10 +187,11 @@ func (i *ImageService) unleaseSnapshotsFromDeletedConfigs(ctx context.Context, p
 
 	var errs error
 	for _, img := range all {
-		err := i.walkPresentChildren(ctx, img.Target, func(_ context.Context, desc ocispec.Descriptor) {
+		err := i.walkPresentChildren(ctx, img.Target, func(_ context.Context, desc ocispec.Descriptor) error {
 			if containerdimages.IsConfigType(desc.MediaType) {
 				delete(possiblyDeletedConfigs, desc.Digest)
 			}
+			return nil
 		})
 		if err != nil {
 			errs = multierror.Append(errs, err)