Migrate leader election to leases

[acumino]

/kind enhancement

Which issue(s) this PR fixes:
Part of gardener/gardener#4742

Special notes for your reviewer:
/cc @ialidzhikov

Release note:

The default leader election resource lock of `machine-controller-manager` has been changed from `endpointsleases` to `leases`.
Please make sure, that you had at least `[email protected]` running before upgrading to `v0.46.0`, so that it has successfully acquired leadership with the hybrid resource lock (`endpointsleases`) at least once.

[gardener-robot]

@acumino Thank you for your contribution.

[ialidzhikov]

Thanks for the PR!
IMO we can mark it ready for review - all MCM providers were released with the endpointsleases resource lock.
We could also check whether the RBAC rules for endpoints can be now removed.

[himanshu-kun]

/lgtm

[ialidzhikov]

We could also check whether the RBAC rules for endpoints can be now removed.

@acumino , any comments on this one?

[acumino]

We could also check whether the RBAC rules for endpoints can be now removed.

@acumino , any comments on this one?

There was not any specific RBAC for endpoints for leader election. I am not sure if mcm still need endpoints apart from the use for leader election if not we can drop it else not.

[ialidzhikov]

There was not any specific RBAC for endpoints for leader election. I am not sure if mcm still need endpoints apart from the use for leader election if not we can drop it else not.

That was the whole point of my comment - to check it :)

I recall some cases when client-go or controller-runtime can try to list endpoints for the kubernetes service in the default namespace. At least we should be able to remove create/patch/update verbs for endpoints from the example RBAC.

[himanshu-kun]

I have tested by removing the endpoints rules from the clusterrole, and tested the following MCM scenarios:

• scaling-up machinedeployment
• scaling-down
• rolling update

There were no logs found stating cannot list endpoint or similar, and there were no restarts of MCM.
Hope these are enough @ialidzhikov

[ialidzhikov]

Okay, my comment was to adapt the example RBAC and remove the endpoints rule. In #662 we adapted the example RBAC to add rules for leases, I guess now we can remove the rules for endpoints.

[ialidzhikov]

/lgtm