fix(sync): fixed checking updates in remote tags digest

pkg/extensions/sync/remote.go

@@ -93,6 +93,33 @@ func (registry *RemoteRegistry) GetImageReference(repo, reference string) (ref.R
 }
 
 func (registry *RemoteRegistry) headManifest(ctx context.Context, imageReference ref.Ref,
+) (manifest.Manifest, error) {
+	/// check what error it gives when not found
+	man, err := registry.client.ManifestHead(ctx, imageReference)
+	if err != nil {
+		/* public registries may return 401 for image not found
+		they will try to check private registries as a fallback => 401 */
+		if errors.Is(err, errs.ErrHTTPUnauthorized) {
+			registry.log.Info().Str("errorType", common.TypeOf(err)).
+				Str("repository", imageReference.Repository).Str("reference", imageReference.Reference).
+				Err(err).Msg("failed to get manifest: unauthorized")
+
+			return nil, zerr.ErrUnauthorizedAccess
+		} else if errors.Is(err, errs.ErrNotFound) {
+			registry.log.Info().Str("errorType", common.TypeOf(err)).
+				Str("repository", imageReference.Repository).Str("reference", imageReference.Reference).
+				Err(err).Msg("failed to find manifest")
+
+			return nil, zerr.ErrManifestNotFound
+		}
+
+		return nil, err
+	}
+
+	return man, nil
+}
+
+func (registry *RemoteRegistry) getManifest(ctx context.Context, imageReference ref.Ref,
 ) (manifest.Manifest, error) {
 	/// check what error it gives when not found
 	man, err := registry.client.ManifestGet(ctx, imageReference)
@@ -134,7 +161,7 @@ func (registry *RemoteRegistry) GetDigest(ctx context.Context, repo, tag string,
 	return man.GetDescriptor().Digest, err
 }
 
-// returns OCI remote digest, original remote digaest (unconverted), if it was converted.
+// returns OCI remote digest, original remote digest (unconverted), if it was converted.
 func (registry *RemoteRegistry) GetOCIDigest(ctx context.Context, repo, tag string,
 ) (godigest.Digest, godigest.Digest, bool, error) {
 	var isConverted bool
@@ -146,7 +173,7 @@ func (registry *RemoteRegistry) GetOCIDigest(ctx context.Context, repo, tag stri
 		return "", "", false, err
 	}
 
-	man, err := registry.headManifest(ctx, imageReference)
+	man, err := registry.getManifest(ctx, imageReference)
 	if err != nil {
 		return "", "", false, err
 	}

pkg/extensions/sync/service.go

@@ -496,16 +496,16 @@ func (service *BaseService) syncRef(ctx context.Context, localRepo string, remot
 }
 
 // get "would be" digest of image after synced.
-func (service *BaseService) getLocalStoredImageDigest(ctx context.Context, repo, tag string,
+func (service *BaseService) computeLocalStoredImageDigest(ctx context.Context, repo, tag string,
 ) (godigest.Digest, godigest.Digest, bool, error) {
 	var err error
 
-	var convertedDigest, remoteDigest godigest.Digest
+	var localDigest, remoteDigest godigest.Digest
 
 	var isConverted bool
 
 	if !service.config.PreserveDigest {
-		convertedDigest, remoteDigest, isConverted, err = service.remote.GetOCIDigest(ctx, repo, tag)
+		localDigest, remoteDigest, isConverted, err = service.remote.GetOCIDigest(ctx, repo, tag)
 		if err != nil {
 			service.log.Error().Err(err).Str("repository", repo).Str("reference", tag).
 				Msg("failed to get upstream image manifest details")
@@ -520,9 +520,12 @@ func (service *BaseService) getLocalStoredImageDigest(ctx context.Context, repo,
 
 			return "", "", false, err
 		}
+
+		// preserve digest is true, so the local digest is same as remote
+		localDigest = remoteDigest
 	}
 
-	return convertedDigest, remoteDigest, isConverted, nil
+	return localDigest, remoteDigest, isConverted, nil
 }
 
 func (service *BaseService) syncImage(ctx context.Context, localRepo, remoteRepo, tag string,
@@ -543,7 +546,7 @@ func (service *BaseService) syncImage(ctx context.Context, localRepo, remoteRepo
 		return err
 	}
 
-	localDigest, remoteDigest, isConverted, err = service.getLocalStoredImageDigest(ctx, remoteRepo, tag)
+	localDigest, remoteDigest, isConverted, err = service.computeLocalStoredImageDigest(ctx, remoteRepo, tag)
 	if err != nil {
 		return err
 	}