Fix env variables propagation to k0s service

[apedriza]

Systemd script was reading the environment variables in the wrong way, so the environment variables were not propagated to the k0s service.

Description

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 own 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

[kke]

Yes we're using .Option['Environment'] for some reason instead of the EnvVars provided in the service struct.

[apedriza]

Since the effort to get rid of the kardianos/service dependency here and test these fix (correct init script generation) involve the integration with it, it has been decided to add tests about the correct init script generation in the future PR after having manually tested the correct functioning of this fix

[k0s-bot]

Git push to origin failed for release-1.28 with exitcode 1

[k0s-bot]

Git push to origin failed for release-1.28 with exitcode 1

[k0s-bot]

Successfully created backport PR for release-1.28:

• [Backport release-1.28] Fix env variables propagation to k0s service #5133

[k0s-bot]

Git push to origin failed for release-1.28 with exitcode 1

[k0s-bot]

Git push to origin failed for release-1.29 with exitcode 1

[k0s-bot]

Git push to origin failed for release-1.29 with exitcode 1

[k0s-bot]

Successfully created backport PR for release-1.29:

• [Backport release-1.29] Fix env variables propagation to k0s service #5134

[k0s-bot]

Git push to origin failed for release-1.29 with exitcode 1

[k0s-bot]

Git push to origin failed for release-1.30 with exitcode 1

[k0s-bot]

Git push to origin failed for release-1.30 with exitcode 1

[k0s-bot]

Successfully created backport PR for release-1.30:

• [Backport release-1.30] Fix env variables propagation to k0s service #5135

[k0s-bot]

Git push to origin failed for release-1.30 with exitcode 1

[k0s-bot]

Git push to origin failed for release-1.31 with exitcode 1

[k0s-bot]

Git push to origin failed for release-1.31 with exitcode 1

[k0s-bot]

Git push to origin failed for release-1.31 with exitcode 1

[k0s-bot]

Successfully created backport PR for release-1.31:

• [Backport release-1.31] Fix env variables propagation to k0s service #5136