Renew etcd certificates generated by custom etcd CA

[byDimasik]

Description

k0s renews certs issued by a custom cluster CA,
and it should do the same for certs issued by
a custom etcd CA.

Fixes #7795

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

How Has This Been Tested?

• Manual test
• Auto test added

Checklist

• My code follows the style guidelines of this project
• My commit messages are signed-off
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have checked my code and corrected any misspellings

[byDimasik]

@twz123 thanks for replaying the tests for me. I looked into the logs from the failed runs and discovered an actual issue with my change. It turned out there are 2 independent cert managers; etcd has its own, and the order of operation is as follows:

1. Common cert manager for all but etcd certs runs
2. Etcd component starts
3. Etcd component uses a second cert manager just for etcd certs

The failure is on step 1 where we expect etcd CA to be created, but it's only created on step 3, so step 1 fails with etcd ca not found error.

I made a change so that I log a warning instead of failing when etcd CA isn't present - https://github.com/k0sproject/k0s/pull/7796/changes#diff-a79868c58696b375941a0e5a2b1787adab963bde4947a06d3f2402e131ba3c3bR226-R232

It should work now.

[byDimasik]

it seems to me the test failures are unrelated to my change. Some happened even before the test started: INTERNAL_ERROR from golang.org. Others finished with random timeouts, the logs didn't show anything useful or related to my change