support OCI image layout target in oras manifest delete

[qweeah]

User should be able to use oras manifest delete to remove a manifest in their OCI layout folder with properly garbage collection.

[sidharthviz]

Hi @qweeah I would like to work on this, Could you assign me for this issue ?

[qweeah]

@sidharthviz Welcome! You might need to start to get familiar with OCI image layout and related oras-go packages. The garbage collection part can be skipped in this issue. It is expected to be done in another command set discussed in #792.

[qweeah]

Hey @sidharthviz I just found that manifest deletion is not implemented on SDK side. I just created a new issue in oras-go to track: oras-project/oras-go#454, which means this issue might take more effort than expected and may not be a good start point to contribute to oras.

Will unassign you and remove the good-first-issue tag, sorry and feel free to choose another one from https://github.com/oras-project/oras/contribute.

[sidharthviz]

Hey @sidharthviz I just found that manifest deletion is not implemented on SDK side. I just created a new issue in oras-go to track: oras-project/oras-go#454, which means this issue might take more effort than expected and may not be a good start point to contribute to oras.

Will unassign you and remove the good-first-issue tag, sorry and feel free to choose another one from https://github.com/oras-project/oras/contribute.

It's alright Billy :)

[qweeah]

both this issue and #761 are depending on merging of oras-project/oras-go#470, moving to 1.2.0 mile stone.

[FeynmanZhou]

As a project maintainer for CNCF Notary Project, I would like to have this feature in ORAS v1.2.0 since it enables Notation users to delete a signature from an image in OCI image layout. See an example usage in registry: https://notaryproject.dev/docs/user-guides/how-to/manage-signatures/#delete-a-signature-on-an-artifact

[shizhMSFT]

Note that oras manifest delete just delete the manifest. To delete an image cleanly, we need the GC feature (oras-project/oras-go#472).