Proposed fix for image content store

Signed-off-by: Daniel Nephin <dnephin@gmail.com>

image.go

@@ -32,6 +32,8 @@ type Image interface {
 	Config(ctx context.Context) (ocispec.Descriptor, error)
 	// IsUnpacked returns whether or not an image is unpacked.
 	IsUnpacked(context.Context, string) (bool, error)
+	// ContentStore provides a content store which contains image blob data
+	ContentStore() content.Store
 }
 
 var _ = (Image)(&image{})
@@ -166,3 +168,7 @@ func (i *image) getLayers(ctx context.Context, platform string) ([]rootfs.Layer,
 	}
 	return layers, nil
 }
+
+func (i *image) ContentStore() content.Store {
+	return i.client.ContentStore()
+}

oci/client.go

@@ -11,11 +11,12 @@ import (
 // Client interface used by SpecOpt
 type Client interface {
 	SnapshotService(snapshotterName string) snapshot.Snapshotter
-	ContentStore() content.Store
 }
 
 // Image interface used by some SpecOpt to query image configuration
 type Image interface {
 	// Config descriptor for the image.
 	Config(ctx context.Context) (ocispec.Descriptor, error)
+	// ContentStore provides a content store which contains image blob data
+	ContentStore() content.Store
 }

oci/spec_opts_unix.go

@@ -67,12 +67,6 @@ func WithLinuxNamespace(ns specs.LinuxNamespace) SpecOpts {
 // WithImageConfig configures the spec to from the configuration of an Image
 func WithImageConfig(image Image) SpecOpts {
 	return func(ctx context.Context, client Client, c *containers.Container, s *specs.Spec) error {
-		store := client.ContentStore()
-		// TODO: needs review. Previous this passed in a store, now it's using
-		// a store that is part of the client. This makes the assumption that
-		// the client store is the same as the one wrapped by `image`.
-		// Is this assumption safe? Should the interface be changed to accept
-		// a store instead of wrapping one?
 		ic, err := image.Config(ctx)
 		if err != nil {
 			return err
@@ -83,7 +77,7 @@ func WithImageConfig(image Image) SpecOpts {
 		)
 		switch ic.MediaType {
 		case v1.MediaTypeImageConfig, images.MediaTypeDockerSchema2Config:
-			p, err := content.ReadBlob(ctx, store, ic.Digest)
+			p, err := content.ReadBlob(ctx, image.ContentStore(), ic.Digest)
 			if err != nil {
 				return err
 			}

oci/spec_opts_windows.go

@@ -17,7 +17,6 @@ import (
 // WithImageConfig configures the spec to from the configuration of an Image
 func WithImageConfig(image Image) SpecOpts {
 	return func(ctx context.Context, client Client, _ *containers.Container, s *specs.Spec) error {
-		store := client.ContentStore()
 		ic, err := image.Config(ctx)
 		if err != nil {
 			return err
@@ -28,7 +27,7 @@ func WithImageConfig(image Image) SpecOpts {
 		)
 		switch ic.MediaType {
 		case v1.MediaTypeImageConfig, images.MediaTypeDockerSchema2Config:
-			p, err := content.ReadBlob(ctx, store, ic.Digest)
+			p, err := content.ReadBlob(ctx, image.ContentStore(), ic.Digest)
 			if err != nil {
 				return err
 			}