fix compat image resolution

Fix a bug in the resolution of images in the Docker compat API.
When looking up an image by a short name, the name may match
an image that does not live on Docker Hub.  The resolved name
should be used for normalization instead of the input name to
make sure that `busybox` can resolve to `registry.com/busybox`
if present in the local storage.

Fixes: #14291
Signed-off-by: Valentin Rothberg <vrothberg@redhat.com>

1 files changed, 9 insertions, 4 deletions

diff --git a/pkg/api/handlers/utils/images.go b/pkg/api/handlers/utils/images.go
index 7154f5616..433231f59 100644
--- a/pkg/api/handlers/utils/images.go
+++ b/pkg/api/handlers/utils/images.go
@@ -26,21 +26,26 @@ func NormalizeToDockerHub(r *http.Request, nameOrID string) (string, error) {
 		return nameOrID, nil
 	}
 
-	// Try to lookup the input to figure out if it was an ID or not.
 	runtime := r.Context().Value(api.RuntimeKey).(*libpod.Runtime)
-	img, _, err := runtime.LibimageRuntime().LookupImage(nameOrID, nil)
+
+	// The candidate may resolve to a local non-Docker Hub image, such as
+	// 'busybox' -> 'registry.com/busybox'.
+	img, candidate, err := runtime.LibimageRuntime().LookupImage(nameOrID, nil)
 	if err != nil {
 		if errors.Cause(err) != storage.ErrImageUnknown {
 			return "", fmt.Errorf("normalizing name for compat API: %v", err)
 		}
+		// If the image could not be resolved locally, set the
+		// candidate back to the input.
+		candidate = nameOrID
 	} else if strings.HasPrefix(img.ID(), strings.TrimPrefix(nameOrID, "sha256:")) {
 		return img.ID(), nil
 	}
 
 	// No ID, so we can normalize.
-	named, err := reference.ParseNormalizedNamed(nameOrID)
+	named, err := reference.ParseNormalizedNamed(candidate)
 	if err != nil {
-		return "", fmt.Errorf("normalizing name for compat API: %v", err)
+		return "", fmt.Errorf("normalizing name %q (orig: %q) for compat API: %v", candidate, nameOrID, err)
 	}
 
 	return named.String(), nil