Provide capability to build experimental image from non-main branch

[tomkerkhove]

Describe the current behavior
#3699 introduces the capability to build experimental images from main branch for every push to it.

Describe the improvement
Provide capability to build experimental image from non-main branch

Additional context
Follow-up after #3682

[tomkerkhove]

Feel free to assign to me

[matthchr]

I've assigned this to you @tomkerkhove.

I'm not 100% sold it makes sense for us to have GH actions for this - it's already possible to test non-main branches locally by using the corresponding task targets, and you can build and push images as well (there are taskfile targets for that as well as provisioning an AKS cluster and launching the local copy of the operator there, or in kind - both are supported).

They may need to be better documented though, so that users who want to do this know how to do so without reading through the Taskfile.

Reason I say this is that I'm not sure we want to host the images in our official ACR like we do for releases and experimental. Happy to discuss this further and be convinced though.

[tomkerkhove]

I think the reasoning for this is primarily to not ask people to go through all of that and if there is a customer that has to validate an issue we can give them the artifacts instead.

However, I get that this might be too much now that we have main images so maybe this is something we should have ourselves on the APIM side (which I have actually just set up)

[tomkerkhove]

@matthchr is this something you are still considering or decided not to do (which would be ok)?

[matthchr]

I don't think we're planning on doing it right now, but we'd probably accept a contribution for it. I don't mind keeping this item open for a while to track the ask even if no immediate action is forthcoming and see if comes up or users are thumbs-up-ing it.

We revisit open issues ~once every 3 months or so, so if in a few months there's not been much need for this we'll probably close it, at least for now.

[tomkerkhove]

That makes sense.

We actually have this available in our fork, so if you are open to it I can just contribute it.

[matthchr]

Do you have a link to how you have it set up in the fork? Let me sync w/ @theunrepentantgeek and check out how you've done it in the fork first?

[tomkerkhove]

It is just as simple as this - https://github.com/ansulgoenka/azure-service-operator/blob/main/.github/workflows/create-release-experimental.yml

But it should likely be improved to not update the existing experimental tag and instead do it with experimental-<branch> to not mess up the "official previews"