Introduce extraInitContainers to helm chart

[strowk]

New extraInitContainers configuration added.
It allows to pass template with a list of containers to execute before
main code-server container started. Main container will only start when
all init containers are completed (exited with 0 code).

Additionally changes the way extraContainers is used - instead of
toYaml use tpl, because this allows to
reference any values from extraContainers string.

close #3392

[codecov]

Codecov Report

Merging #3393 (43d72c5) into main (8f3de91) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #3393   +/-   ##
=======================================
  Coverage   59.21%   59.21%           
=======================================
  Files          35       35           
  Lines        1709     1709           
  Branches      379      379           
=======================================
  Hits         1012     1012           
  Misses        559      559           
  Partials      138      138           

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 8f3de91...43d72c5. Read the comment docs.

[repo-ranger]

Thanks for making your first contribution! 🙂

[jsjoeio]

Thanks for opening an issue and raising a PR @strowk 🎉

This sounds like a great addition but would love to get some extra eyes on it from the other code-server team members.

In the meantime, can you:

• rebase so your branch is up to date with main
• update the CHANGELOG

[jsjoeio]

cc @alexgorbatchev and @Matthew-Beckett - any chance either of you would be able to help review this?

[strowk]

@jsjoeio , rebased on main and also updated changelog. I guess that next version should be 3.11.0, since this is kinda new feature (even though only for helm chart)

[strowk]

Upd: changed entry in changelog to "Next Version" for now, guess there could be more stuff in there before next release.. (sorry for after review change)

[Matthew-Beckett]

@jsjoeio can you advise on the CHANGELOG before I approve? Not sure on the rules for adding changes being a part time maintainer. This pull has a milestone associated with it so is @strowk correct to put it in "Next Update"?

[jsjoeio]

@strowk thanks for making those changes! Using "Next Version" in the CHANGELOG is correct (apologies, it's new and we need to add more documentation around that #3412).

@Matthew-Beckett looks good from our side. Thanks so much for reviewing this so quickly and helping out with maintaining code-server! We really appreciate it.

[Matthew-Beckett]

@strowk nice work!

@jsjoeio it's my pleasure, any time.