Add an external controller metrics service

[vladsf]

If a LINSTOR controller is external (piraeus chart installed with .Values.externalController.url set) then the external controller requires an Endpoint and an extra Service to make metrics available via ServiceMonitor.

This PR addresses the issue.

[WanzenBug]

Thanks! I left a few comments

[WanzenBug]

I'm a bit slow today: actually, this whole thing should be moved to https://github.com/piraeusdatastore/helm-charts/tree/main/charts/linstor-cluster

There, we already have the externalController logic and even deploy a monitoring.

Sorry for the confusion. This helm chart also needs to be somehow moved there eventually.

[vladsf]

I'm a bit slow today: actually, this whole thing should be moved to https://github.com/piraeusdatastore/helm-charts/tree/main/charts/linstor-cluster

There, we already have the externalController logic and even deploy a monitoring.

Sorry for the confusion. This helm chart also needs to be somehow moved there eventually.

I have not found externalController logic there. I guess I should abandon this PR?

[WanzenBug]

I have not found externalController logic there. I guess I should abandon this PR?

Yes. Move it over to the other repo. There, users can already set linstorCluster.externalController.url. The chart here is just for deploying the operator, but stuff like setting up the LinstorCluster resource and setting up monitoring is controlled over there.