Expand image refs and handle refs with digests

If an image that we're pulling from a registry has a digest in its
reference, use that to construct the destination image's reference.
This should help us detect cases where the image has previously been
pulled.

When we have a filter to use when listing images, expand it into a
reference so that we can properly match against names of images that
we've previously stored using fully expanded references.

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

pkg/storage/image.go

@@ -43,7 +43,19 @@ type ImageServer interface {
 func (svc *imageService) ListImages(filter string) ([]ImageResult, error) {
 	results := []ImageResult{}
 	if filter != "" {
-		if image, err := svc.store.GetImage(filter); err == nil {
+		ref, err := alltransports.ParseImageName(filter)
+		if err != nil {
+			ref2, err2 := istorage.Transport.ParseStoreReference(svc.store, "@"+filter)
+			if err2 != nil {
+				ref3, err3 := istorage.Transport.ParseStoreReference(svc.store, filter)
+				if err3 != nil {
+					return nil, err
+				}
+				ref2 = ref3
+			}
+			ref = ref2
+		}
+		if image, err := istorage.Transport.GetStoreImage(svc.store, ref); err == nil {
 			results = append(results, ImageResult{
 				ID:    image.ID,
 				Names: image.Names,
@@ -136,6 +148,9 @@ func (svc *imageService) PullImage(systemContext *types.SystemContext, imageName
 		if tagged, ok := srcRef.DockerReference().(reference.NamedTagged); ok {
 			dest = dest + ":" + tagged.Tag()
 		}
+		if canonical, ok := srcRef.DockerReference().(reference.Canonical); ok {
+			dest = dest + "@" + canonical.Digest().String()
+		}
 	}
 	destRef, err := istorage.Transport.ParseStoreReference(svc.store, dest)
 	if err != nil {

test/image.bats

@@ -32,6 +32,36 @@ function teardown() {
 	stop_ocid
 }
 
+@test "image pull and list by digest" {
+	start_ocid "" "" --no-pause-image
+	run ocic image pull nginx@sha256:4aacdcf186934dcb02f642579314075910f1855590fd3039d8fa4c9f96e48315
+	echo "$output"
+	[ "$status" -eq 0 ]
+
+	run ocic image list --quiet nginx@sha256:4aacdcf186934dcb02f642579314075910f1855590fd3039d8fa4c9f96e48315
+	[ "$status" -eq 0 ]
+	echo "$output"
+	[ "$output" != "" ]
+
+	run ocic image list --quiet nginx@4aacdcf186934dcb02f642579314075910f1855590fd3039d8fa4c9f96e48315
+	[ "$status" -eq 0 ]
+	echo "$output"
+	[ "$output" != "" ]
+
+	run ocic image list --quiet @4aacdcf186934dcb02f642579314075910f1855590fd3039d8fa4c9f96e48315
+	[ "$status" -eq 0 ]
+	echo "$output"
+	[ "$output" != "" ]
+
+	run ocic image list --quiet 4aacdcf186934dcb02f642579314075910f1855590fd3039d8fa4c9f96e48315
+	[ "$status" -eq 0 ]
+	echo "$output"
+	[ "$output" != "" ]
+
+	cleanup_images
+	stop_ocid
+}
+
 @test "image list with filter" {
 	start_ocid "" "" --no-pause-image
 	run ocic image pull "$IMAGE"
@@ -64,6 +94,7 @@ function teardown() {
 	run ocic image list --quiet
 	echo "$output"
 	[ "$status" -eq 0 ]
+	[ "$output" != "" ]
 	printf '%s\n' "$output" | while IFS= read -r id; do
 		run ocic image remove --id "$id"
 		echo "$output"
@@ -72,6 +103,7 @@ function teardown() {
 	run ocic image list --quiet
 	echo "$output"
 	[ "$status" -eq 0 ]
+	[ "$output" = "" ]
 	printf '%s\n' "$output" | while IFS= read -r id; do
 		echo "$id"
 		status=1
@@ -88,10 +120,12 @@ function teardown() {
 	run ocic image list --quiet
 	echo "$output"
 	[ "$status" -eq 0 ]
+	[ "$output" != "" ]
 	printf '%s\n' "$output" | while IFS= read -r id; do
 		run ocic image status --id "$id"
 		echo "$output"
 		[ "$status" -eq 0 ]
+		[ "$output" != "" ]
 		run ocic image remove --id "$id"
 		echo "$output"
 		[ "$status" -eq 0 ]
@@ -99,6 +133,7 @@ function teardown() {
 	run ocic image list --quiet
 	echo "$output"
 	[ "$status" -eq 0 ]
+	[ "$output" = "" ]
 	printf '%s\n' "$output" | while IFS= read -r id; do
 		echo "$id"
 		status=1