feat(hbase): add hbase-entrypoint.sh script

[razvan]

Description

prere-quisite for : stackabletech/hbase-operator#570

Definition of Done Checklist

• Not all of these items are applicable to all PRs, the author should update this template to only leave the boxes in that are relevant
• Please make sure all these things are done and tick the boxes

- [ ] Changes are OpenShift compatible
- [ ] All added packages (via microdnf or otherwise) have a comment on why they are added
- [ ] Things not downloaded from Red Hat repositories should be mirrored in the Stackable repository and downloaded from there
- [ ] All packages should have (if available) signatures/hashes verified
- [ ] Add an entry to the CHANGELOG.md file
- [ ] Integration tests ran successfully

TIP: Running integration tests with a new product image

The image can be built and uploaded to the kind cluster with the following commands:

bake --product <product> --image-version <stackable-image-version>
kind load docker-image <image-tagged-with-the-major-version> --name=<name-of-your-test-cluster>

See the output of bake to retrieve the image tag for <image-tagged-with-the-major-version>.

[NickLarsenNZ]

LGTM

[NickLarsenNZ]

Approving so we aren't blocked, but would like some light docs on the traps/signal handlin.

[lfrancke]

@razvan would we revert this if we decide not to merge the other related graceful shutdown tickets?

[razvan]

It's not used and has no impact if it stays.

Personally I would prefer to create entry point scripts for all products and get rid of the hard-coded shell snippets in the operators.

But if it bothers you, I can revert it.

[lfrancke]

It doesn't. I was just wondering.