Remove simulated pull by id from v2 registry

pkg/dockerregistry/server/repositorymiddleware.go

@@ -115,36 +115,11 @@ func (r *repository) Get(ctx context.Context, dgst digest.Digest) (*manifest.Sig
 
 // Get retrieves the named manifest, if it exists.
 func (r *repository) GetByTag(ctx context.Context, tag string) (*manifest.SignedManifest, error) {
-	var image *imageapi.Image
-	if imageStreamTag, err := r.getImageStreamTag(ctx, tag); err == nil {
-		image = &imageStreamTag.Image
-	} else {
-		// TODO remove when docker 1.6 is out
-		// Since docker 1.5 doesn't support pull by id, we're simulating pull by id
-		// against the v2 registry by using a pull spec of the form
-		// <repo>:<hex portion of digest>, so once we verify we got a 404 from
-		// getImageStreamTag, we construct a digest and attempt to get the
-		// imageStreamImage using that digest.
-		if err, ok := err.(*kerrors.StatusError); !ok {
-			log.Errorf("GetByTag: getImageStreamTag returned error: %s", err)
-			return nil, err
-		} else if err.ErrStatus.Code != http.StatusNotFound {
-			log.Errorf("GetByTag: getImageStreamTag returned non-404: %s", err)
-		}
-
-		// let's try to get by id
-		dgst, dgstErr := digest.ParseDigest("sha256:" + tag)
-		if dgstErr != nil {
-			log.Errorf("GetByTag: unable to parse digest: %s", dgstErr)
-			return nil, err
-		}
-		imageStreamImage, err := r.getImageStreamImage(ctx, dgst)
-		if err != nil {
-			log.Errorf("GetByTag: getImageStreamImage returned error: %s", err)
-			return nil, err
-		}
-		image = &imageStreamImage.Image
+	imageStreamTag, err := r.getImageStreamTag(ctx, tag)
+	if err != nil {
+		return nil, err
 	}
+	image := &imageStreamTag.Image
 
 	dgst, err := digest.ParseDigest(image.Name)
 	if err != nil {