Expose garbageCollection setting in kubernetes variable as a helm value

[ben-dov]

Is your feature request related to a problem? Please describe

I find that if jenkins controller pod restarts when a worker pod is still Pending, then the resulting worker cannot connect to the controller.
It seems the worker is stuck in a loop where it tries to connect and must be terminated.

Describe the solution you'd like

The kubernetes plugin allows configuring a garbage collection that seems to delete these pods, but there is no way to configure it from the helm values when setting controller.JCasC.defaultConfig to true. In that case, attempting to use controller.JCasC.defaultConfig just creates another cloud.

I would like to to be able to configure the functionality without setting controller.JCasC.defaultConfig to false.

Describe alternatives you've considered

I can set controller.JCasC.defaultConfig to false, but it will be a non trivial refactor.

Additional context

the change it self should be pretty small, just adding the following lines to the the helm values

controller:
  garbageCollection:
    enabled: false
    namespaces: ""
    timeout: 300

And relevant condition in the _helpers.tpl that sets jenkins.casc.defaults

[timja]

A pull request would be welcome

[ben-dov]

@timja created 😃