make the ojp-server docker image leaner

[rrobetti]

We want to make our docker image more lean for the OJP server, some research is required on how to improve it, it might be just the case of using an apline base image instead of ubuntu one for eclipse-temurin:22-jre -> eclipse-temurin:22-jre-alpine but I would like some more research to see if other things can be done to reduce it even further.
If you want to pick one of these tasks let me know and I will give you more information on it.

[jether2011]

Hey @rrobetti could I try this one?

[rrobetti]

Hey @rrobetti could I try this one?

@jether2011 sure, work away.

[matheusandre1]

Work on that?
I would have to create a Dockerfile and apply the multistage build pattern, right?

[rrobetti]

@matheusandre1 I would jut switch to use eclipse-temurin:22-jre-alpine and run tests against it, and also check the size reduction. If that works is already a win. Once that works we can try the multistage build pattern if you feel it will improve it further.
@jether2011 are you working on this issue? if not and if that is ok with you, can you assign it to Matheus?

[matheusandre1]

@rrobetti OK, if @jether2011 If you allow me to create this issue, I can optimize and leverage issue #49,

I verified that the ojp-server project uses the Jib Maven Plugin, I can extract it to a Dockerfile, if that doesn't affect the project structure. I await your guidance.

[jether2011]

Hey @matheusandre1, I've assigned the task for you.

[DominikZig]

Hi all,

I am thinking if it is more suitable to use the new Docker Hardened Images equivalent of Temurin (https://hub.docker.com/hardened-images/catalog/dhi/eclipse-temurin) if possible?

Because that eclipse-temurin:22-jre-alpine image in the proposed PR still has multiple critical severity CVEs in it, whereas hardened one has zero CVEs. It also has the added benefit of being significantly leaner in general (around ~30MBs total).