Copy Annotations into config.json (Docker Labels)

[amouat]

Apko currently supports adding annotations as per the OCI Image spec: https://github.com/opencontainers/image-spec/blob/main/annotations.md

Docker's support for annotations seems a bit mixed, and in particular docker inspect will not display annotations. For this reason, it might be worth adding annotations into the config, which will get surfaced in docker inspect and easily found/searched/scripted etc.

[mritunjaysharma394]

Hi @amouat, I am not sure if I understood what we meant by config here, is it : ~/.docker/config.json ( a guess because of the title of the issue but I don't think we will make the change here so it may be something else) or this https://github.com/google/go-containerregistry/blob/main/pkg/v1/image.go (feels more like this) or the config.json that couples with rootfs as a bundle to be finally run by runc at the lower levels?

So if we try to understand you suggested adding the Annotations field in a modified version of v1/image.go specific for our use case of allowing them to be visible in docker inspect?

[mritunjaysharma394]

Oh okay I think I got it, you probably meant this right which becomes the eventual config.json + rootfs bundle? So how do we plan to copy it here, by creating a new field for annotations right?

[amouat]

More or less @mritunjaysharma394. I'm talking about this file to be exact, which is in every image tarball.

My suggestion is not to add anything new to the apko yaml, but when building the image add annotations both in the manifest and as Labels in the config.json. Then they will appear in docker inspect which basically displays and parses the config.json.

[mritunjaysharma394]

Oh that makes sense, thanks a bunch @amouat, I think so that more or less I have understood the assignment here:

• update Labels which are a map so annotations can be hopefully easily added here.
• we already have Annotations in Manifest struct so that should be handleable too to add the annotations?

If that sounds okay, maybe I can try to get my hands dirty and create a proposal/PR/Draft PR to implement this? Thanks again 🙏

[amouat]

That would be great @mritunjaysharma394! However, I would like @kaniini or someone to verify that we do want this functionality first.

Assuming we do, it's hopefully just a case of copying the annotations struct into the labels struct for the config.