Parse out image names as repotags and repodigests

Parse the set of image names as tagged references, canonical references,
or repository names to which we add the default tag, and return them in
libkpod.ImageData reports.

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>

libkpod/image/imageData.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"time"
 
+	"github.com/containers/image/docker/reference"
 	"github.com/containers/storage"
 	"github.com/kubernetes-incubator/cri-o/libkpod/driver"
 	digest "github.com/opencontainers/go-digest"
@@ -15,8 +16,8 @@ import (
 // nolint
 type ImageData struct {
 	ID              string
-	Names           []string
+	Tags            []string
-	Digests         []digest.Digest
+	Digests         []string
 	Parent          string
 	Comment         string
 	Created         *time.Time
@@ -58,6 +59,32 @@ type rootFS struct {
 	Layers []string
 }
 
+// ParseImageNames parses the names we've stored with an image into a list of
+// tagged references and a list of references which contain digests.
+func ParseImageNames(names []string) (tags, digests []string, err error) {
+	for _, name := range names {
+		if named, err := reference.ParseNamed(name); err == nil {
+			if digested, ok := named.(reference.Digested); ok {
+				canonical, err := reference.WithDigest(named, digested.Digest())
+				if err == nil {
+					digests = append(digests, canonical.String())
+				}
+			} else {
+				if reference.IsNameOnly(named) {
+					named = reference.TagNameOnly(named)
+				}
+				if tagged, ok := named.(reference.Tagged); ok {
+					namedTagged, err := reference.WithTag(named, tagged.Tag())
+					if err == nil {
+						tags = append(tags, namedTagged.String())
+					}
+				}
+			}
+		}
+	}
+	return tags, digests, nil
+}
+
 // GetImageData gets the ImageData for a container with the given name in the given store.
 func GetImageData(store storage.Store, name string) (*ImageData, error) {
 	img, err := FindImage(store, name)
@@ -69,7 +96,7 @@ func GetImageData(store storage.Store, name string) (*ImageData, error) {
 	if err != nil {
 		return nil, errors.Wrapf(err, "error reading image %q", name)
 	}
-	digests, err := getDigests(*img)
+	blobDigests, err := getDigests(*img)
 	if err != nil {
 		return nil, err
 	}
@@ -77,8 +104,8 @@ func GetImageData(store storage.Store, name string) (*ImageData, error) {
 	var bigData interface{}
 	ctrConfig := containerConfig{}
 	container := ""
-	if len(digests) > 0 {
+	if len(blobDigests) > 0 {
-		bd, err := store.ImageBigData(img.ID, string(digests[len(digests)-1]))
+		bd, err := store.ImageBigData(img.ID, string(blobDigests[len(blobDigests)-1]))
 		if err != nil {
 			return nil, err
 		}
@@ -98,6 +125,11 @@ func GetImageData(store storage.Store, name string) (*ImageData, error) {
 		}
 	}
 
+	tags, digests, err := ParseImageNames(img.Names)
+	if err != nil {
+		return nil, errors.Wrapf(err, "error parsing image names for %q", name)
+	}
+
 	driverName, err := driver.GetDriverName(store)
 	if err != nil {
 		return nil, err
@@ -107,6 +139,7 @@ func GetImageData(store storage.Store, name string) (*ImageData, error) {
 	if err != nil {
 		return nil, err
 	}
+
 	driverMetadata, err := driver.GetDriverMetadata(store, topLayerID)
 	if err != nil {
 		return nil, err
@@ -128,7 +161,7 @@ func GetImageData(store storage.Store, name string) (*ImageData, error) {
 
 	return &ImageData{
 		ID:              img.ID,
-		Names:           img.Names,
+		Tags:            tags,
 		Digests:         digests,
 		Parent:          string(cid.Docker.Parent),
 		Comment:         cid.OCIv1.History[0].Comment,