✨ Able to run controller inside the container platform with write access to root restrictions

[dmvolod]

What this PR does / why we need it:
This fix allows you to run a container with an operator on platforms that do not allow writing data to the root directory, such as OpenShift.

The approach used is very simple, we mount /xdg as an emptyDir volume and redirect XDG_* variables used by helm there. This should work for upstream Kubernetes as well, but e2e validation is required.

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #236

[k8s-ci-robot]

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[k8s-ci-robot]

Hi @dmvolod. Thanks for your PR.

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[Jont828]

/ok-to-test

[Jont828]

Thanks for picking this up! Is the idea here just to mount the /xdg path and expect the user or management cluster to populate it? And are you able to test this with OpenShift and verify that it works?

[dmvolod]

Thanks for picking this up! Is the idea here just to mount the /xdg path and expect the user or management cluster to populate it? And are you able to test this with OpenShift and verify that it works?

Yes, I also changed the container security parameter readOnlyRootFilesystem to true in the next commit. This aligns our approach to running the controller inside OpenShift or a platform with similar security restrictions. Tested it, but not on OpenShift, seems to should work. Please run e2e again.

[dmvolod]

@Jont828 could you please to point me to the deployed addon prodived helm container pod logs in failed CI.

[dmvolod]

@Jont828 could you please to point me to the deployed addon prodived helm container pod logs in failed CI.

Oh, ran it locally and know why it happens, /tmp is also using as rw volume. Will fix soon.

[dmvolod]

We can use single tmp volume mounted to the /tmp and utilize it for all temporary files (common and XDG based). @Jont828 what do you think about it? This should work for all Kubernetes platforms and security restrictions