Convenience method to attach artifact

[jonesbusy]

Description of the bug

Right now to attach an artifact to an other one we need to do the following

(pseudo code)

ContainerRef containerRef = ContainerRef.parse("localhost:5000/artifact-maven");
Manifest manifest = registry.pushArtifact(containerRef, "artifactType", localPath);
Layer layer = registry.pushBlobStream(containerRef, is, size);
Manifest attachedManifest= Manifest.empty().withSubject(manifest.getDescriptor().toSubject()).withAnnotations(Map.of(Const.ANNOTATION_CREATED, Const.currentTimestamp())).withLayers(List.of(layer)).withArtifactType("maven");
registry.pushManifest(containerRef.withDigest(SupportedAlgorithm.SHA256.digest(attachedManifest.toJson().getBytes(StandardCharsets.UTF_8))), attachedManifest);

Creating a method on Registry to perform such operation is a must

[sparsh3007]

Hi @jonesbusy,

Would you say this is a good first issue or a good start point to contribute here? If not, can you suggest one?

[jonesbusy]

Well I've started already this one. But referers on the test registry doesn't full implement the spec

This flow need to be implemented first: https://github.com/opencontainers/distribution-spec/blob/main/spec.md#pushing-manifests-with-subject

So not really a good first issue

Perhaps this one #13 ? Also need to double check if the current blob upload follow the spec or not. I'm not planning to work on it any time soon

[jonesbusy]

While switching from registry to zot it looks the pushStream doesn't fully work and a 400 is received.

I think I will remove this method until correct chunk upload are implemented.

I think it's overly complex to push a stream on the monolitic push (that should be reserved for small blob)