Provide a way to create manifest config conform to mounting the image as a volume with containerd/crio etc

What would you like to be added?

Provide a way to push an artifact layer with a manifest config containing the mimics of an oci runtime image.

See:

• https://github.com/containerd/containerd/issues/11907
• https://github.com/containerd/containerd/issues/11381

It will still take a lot of time util oci artifacts will be supported natively, see https://github.com/kubernetes/enhancements/tree/master/keps/sig-node/4639-oci-volume-source#kubelet-and-container-runtime-interface-cri-support-for-oci-artifacts

Why is this needed for ORAS?

One of the main benefits from oras would be to mount the images into a pod as a volume. Currently that is not possible as containerd does not support the oci artifact spec. You need the rootfs element with the diffId digest of the uncompressed layer.

Are you willing to submit PRs to contribute to this feature?

• Yes, I am willing to implement it.

No repository files, tests, or entry points are identified in the issue. Start by reading the linked containerd issues and Kubernetes KEP, then inspect how oras-java represents artifact layers and manifest configs; done means producing a config with the uncompressed layer diffId and rootfs information needed to mount the artifact as a volume.