Merge pull request #510 from imeoer/backport-v0.9

converter: allow controlling referrer with option

pkg/converter/convert_unix.go

@@ -1009,10 +1009,12 @@ func convertManifest(ctx context.Context, cs content.Store, oldDesc ocispec.Desc
 	// Update the config gc label
 	manifestLabels[configGCLabelKey] = newConfigDesc.Digest.String()
 
-	// Associate a reference to the original OCI manifest.
-	// See the `subject` field description in
-	// https://github.com/opencontainers/image-spec/blob/main/manifest.md#image-manifest-property-descriptions
-	manifest.Subject = &oldDesc
+	if opt.WithReferrer {
+		// Associate a reference to the original OCI manifest.
+		// See the `subject` field description in
+		// https://github.com/opencontainers/image-spec/blob/main/manifest.md#image-manifest-property-descriptions
+		manifest.Subject = &oldDesc
+	}
 
 	// Update image manifest in content store.
 	newManifestDesc, err := writeJSON(ctx, cs, manifest, manifestDesc, manifestLabels)

pkg/converter/types.go

@@ -105,6 +105,16 @@ type MergeOption struct {
 	OCI bool
 	// OCIRef enables converting OCI tar(.gz) blob to nydus referenced blob.
 	OCIRef bool
+	// WithReferrer associates a reference to the original OCI manifest.
+	// See the `subject` field description in
+	// https://github.com/opencontainers/image-spec/blob/main/manifest.md#image-manifest-property-descriptions
+	//
+	// With this association, we can track all nydus images associated with
+	// an OCI image. For example, in Harbor we can cascade to show nydus
+	// images linked to an OCI image, deleting the OCI image can also delete
+	// the corresponding nydus images. At runtime, nydus snapshotter can also
+	// automatically upgrade an OCI image run to nydus image.
+	WithReferrer bool
 	// Backend uploads blobs generated by nydus-image builder to a backend storage.
 	Backend Backend
 	// Timeout cancels execution once exceed the specified time.