Use a single custom annotation for export

Remove annotation prefix and add multiple index records
for manifests with multiple image names. This makes the
custom annotation more consistent with the OCI image
annotation. Additionally, ensure the OCI image annotation
always represents the tag (partial image name) as recommended
by the specification. The containerd image name annotation
will always contain the full image name.

Signed-off-by: Derek McGowan <derek@mcgstyle.net>

images/archive/reference.go

@@ -19,7 +19,8 @@ package archive
 import (
 	"strings"
 
-	"github.com/docker/distribution/reference"
+	"github.com/containerd/containerd/reference"
+	distref "github.com/docker/distribution/reference"
 	"github.com/opencontainers/go-digest"
 	"github.com/pkg/errors"
 )
@@ -69,7 +70,7 @@ func isImagePrefix(s, prefix string) bool {
 
 func normalizeReference(ref string) (string, error) {
 	// TODO: Replace this function to not depend on reference package
-	normalized, err := reference.ParseDockerRef(ref)
+	normalized, err := distref.ParseDockerRef(ref)
 	if err != nil {
 		return "", errors.Wrapf(err, "normalize image ref %q", ref)
 	}
@@ -78,13 +79,28 @@ func normalizeReference(ref string) (string, error) {
 }
 
 func familiarizeReference(ref string) (string, error) {
-	named, err := reference.ParseNormalizedNamed(ref)
+	named, err := distref.ParseNormalizedNamed(ref)
 	if err != nil {
 		return "", errors.Wrapf(err, "failed to parse %q", ref)
 	}
-	named = reference.TagNameOnly(named)
+	named = distref.TagNameOnly(named)
 
-	return reference.FamiliarString(named), nil
+	return distref.FamiliarString(named), nil
+}
+
+func ociReferenceName(name string) string {
+	// OCI defines the reference name as only a tag excluding the
+	// repository. The containerd annotation contains the full image name
+	// since the tag is insufficent for correctly naming and referring to an
+	// image
+	var ociRef string
+	if spec, err := reference.Parse(name); err == nil {
+		ociRef = spec.Object
+	} else {
+		ociRef = name
+	}
+
+	return ociRef
 }
 
 // DigestTranslator creates a digest reference by adding the