Publish experimental `jlink` image for newer JDK(s)

[lemeurherve]

As we can't currently properly test and validate jlink usage in newer JDKs and as it's more and more difficult to implement, it has been removed from JDK25 images in #1129.

But as jlink allows significant image size reduction, we should continue investing some efforts to support it.

We could publish an experimental image using jlink.

Refs:

• Don't use jlink in newer JDKs images until properly tested #1124
• Don't use jlink in newer JDKs images until properly tested #1124 (comment)
• Generate smaller java runtime with jlink in Windows images #788

[dduportal]

I'm not in favor of having "experimental" or "scary" tags in (docker.io/)jenkins/inbound-agent. It should be a clean area with only clean tags and images.

The idea of validating early experiment used to be implemented with docker4eval in the past: a distinct namespace is key to a safe management. I vote for using an alternative namespace or even registry (GHCR)?

[lemeurherve]

I totally agree! (I should have though about it 😅)

I propose to start with jenkins4eval (as already available) and a simpler experimental-jlink tag first, then to publish on GHCR, WDYT?

[dduportal]

I totally agree! (I should have though about it 😅)

I propose to start with jenkins4eval (as already available) and a simpler experimental-jlink tag first, then to publish on GHCR, WDYT?

That look a really good idea: let's double check with other maintainers if they agree/disagree though

[MarkEWaite]

I propose to start with jenkins4eval (as already available) and a simpler experimental-jlink tag first, then to publish on GHCR, WDYT?

I like that idea very much

[timja]

sounds fine