added option to use emptyDir as additional mount

[mdarii]

related to issue: #484

This commit would allow to add additional volumes as emptyDir, this is necessary if readOnlyRootFilesystem=true

[idanl21]

@mdarii
Please take a look

[swoehrl-mw]

Hi @mdarii.
Thank you for your contribution.

I have some comments:

• Please add a unittest for the new functionality to verify it works (you can extend the test in controllers/cluster_test.go by adding an additionalVolume to the spec and verifying the volume(mount) is part of the created STS).
• Extend the section on "Additional Volumes" in the userguide
• Extend the CRD reference (docs/designs/crd.md)

[mdarii]

Hi @swoehrl-mw , I've updated my PR.

[swoehrl-mw]

@mdarii Code looks good, please check why the tests fail and fix if necessary.

[mdarii]

@swoehrl-mw I'll look into it, but most probably next week

[mdarii]

@swoehrl-mw looks like I've found typo, can you please retrigger pipeline?

[swoehrl-mw]

@mdarii Could you please merge in the current main? There is a fix that should deal with the failing functionaltests check so we can then hopefully merge this PR.

[idanl21]

@mdarii
Hey , do you plan to continue that PR ?

[mdarii]

@mdarii Hey , do you plan to continue that PR ?

yes, I'll try to come back to it somehow this week

[mdarii]

@swoehrl-mw could you trigger pipeline please, I've synced repo with master

[swoehrl-mw]

LGTM