Add some CI to expire unnecessary quay.io images

[alexiri]

When the CI runs (in PRs, particularly), it's going to build images and push them to quay.io. These images may not actually be useful to keep around, and they may eventually add up to quite some space, so we may want to set up some way to reduce the space they take up.

[imbev]

There may be a way to configure the Quay.io expiry time in the quay web UI without CI.

[alexiri]

There is, but only manually per tag, so not super useful. We can also set a label like quay.expires-after=24h on the image itself, but we'd need to do that only on non-main builds or something like that.

https://docs.redhat.com/en/documentation/red_hat_quay/3.8/html/use_red_hat_quay/working_with_tags

[imbev]

What are the different categories of builds that should have different expiry dates?

[alexiri]

• builds from main, aka production images -> no expiration
• all other builds, aka dev images -> 24h? a week?

Ideally, it would probably make sense to expire prod images too, but keep the last 50 images or whatever, but that may be more complicated. I'm biased by the registry expiration options on GitLab.

[imbev]

Do we really need dev images pushed to quay? Couldn't those be built locally instead?

[hanthor]

Ghcr.io automatically deletes images over time. We can follow their policy maybe?

[imbev]

We could push dev images to ghcr and prod images to quay.

[alexiri]

Yes, that could be a good idea too.