Fixes for imgutil from recent refactor

cnb_image.go

@@ -10,7 +10,6 @@ import (
 	v1 "github.com/google/go-containerregistry/pkg/v1"
 	"github.com/google/go-containerregistry/pkg/v1/mutate"
 	"github.com/google/go-containerregistry/pkg/v1/tarball"
-	"github.com/google/go-containerregistry/pkg/v1/validate"
 )
 
 // CNBImageCore wraps a v1.Image and provides most of the methods necessary for the image to satisfy the Image interface.
@@ -184,11 +183,6 @@ func (i *CNBImageCore) UnderlyingImage() v1.Image {
 	return i.Image
 }
 
-func (i *CNBImageCore) Valid() bool {
-	err := validate.Image(i.Image)
-	return err == nil
-}
-
 // TBD Deprecated: Variant
 func (i *CNBImageCore) Variant() (string, error) {
 	configFile, err := getConfigFile(i.Image)

layout/layout.go

@@ -66,6 +66,11 @@ func (i *Image) Identifier() (imgutil.Identifier, error) {
 	return newLayoutIdentifier(i.repoPath, hash)
 }
 
+func (i *Image) Valid() bool {
+	// layout images may be invalid if they are missing layer data
+	return true
+}
+
 func (i *Image) Delete() error {
 	return os.RemoveAll(i.repoPath)
 }

local/local.go

@@ -46,6 +46,11 @@ func (i *Image) Identifier() (imgutil.Identifier, error) {
 	}, nil
 }
 
+func (i *Image) Valid() bool {
+	// local images are actually always invalid, because they are missing a manifest, but let's ignore that for now
+	return true
+}
+
 // GetLayer returns an io.ReadCloser with uncompressed layer data.
 // The layer will always have data, even if that means downloading ALL the image layers from the daemon.
 func (i *Image) GetLayer(diffID string) (io.ReadCloser, error) {

local/v1_facade.go

@@ -184,7 +184,7 @@ var _ v1.Layer = &v1LayerFacade{}
 type v1LayerFacade struct {
 	diffID       v1.Hash
 	uncompressed func() (io.ReadCloser, error)
-	size         func() (int64, error)
+	sentinelSize func() (int64, error)
 }
 
 func newEmptyLayer(diffID v1.Hash, store *Store) *v1LayerFacade {
@@ -197,7 +197,7 @@ func newEmptyLayer(diffID v1.Hash, store *Store) *v1LayerFacade {
 			}
 			return io.NopCloser(bytes.NewReader([]byte{})), nil
 		},
-		size: func() (int64, error) {
+		sentinelSize: func() (int64, error) {
 			layer, err := store.LayerByDiffID(diffID)
 			if err == nil {
 				return layer.Size()
@@ -224,19 +224,12 @@ func newDownloadableEmptyLayer(diffID v1.Hash, store *Store, imageID string) *v1
 			}
 			return nil, err
 		},
-		size: func() (int64, error) {
+		sentinelSize: func() (int64, error) {
 			layer, err := store.LayerByDiffID(diffID)
 			if err == nil {
 				return layer.Size()
 			}
-			if err = store.downloadLayersFor(imageID); err != nil {
-				return -1, err
-			}
-			layer, err = store.LayerByDiffID(diffID)
-			if err == nil {
-				return layer.Size()
-			}
-			return -1, err
+			return -1, nil
 		},
 	}
 }
@@ -251,7 +244,7 @@ func newPopulatedLayer(diffID v1.Hash, fromPath string, sentinelSize int64) *v1L
 			}
 			return f, nil
 		},
-		size: func() (int64, error) {
+		sentinelSize: func() (int64, error) {
 			return sentinelSize, nil
 		},
 	}
@@ -287,7 +280,7 @@ func (l *v1LayerFacade) Uncompressed() (io.ReadCloser, error) {
 
 // Size returns a sentinel value indicating if the layer has data.
 func (l *v1LayerFacade) Size() (int64, error) {
-	return l.size()
+	return l.sentinelSize()
 }
 
 func (l *v1LayerFacade) MediaType() (v1types.MediaType, error) {

remote/remote.go

@@ -74,10 +74,6 @@ func (i *Image) Identifier() (imgutil.Identifier, error) {
 }
 
 // Valid returns true if the (saved) image is valid.
-// It differs from CNBImageCore.Valid() in that the latter validates the current working image (not what is already saved).
-// Additionally, when the repoName for the image is a manifest list, this method validates the entire index.
-// Finally, this method uses validate.Fast, whereas CNBImageCore.Valid() does not.
-// FIXME: see if this can be combined with CNBImageCore.Valid()
 func (i *Image) Valid() bool {
 	return i.valid() == nil
 }