assigning svc CLuster IP when svc is a NodePort

[hamzabouissi]

Summary

Related issues

Checklist

• reference any related issues
• updated docs
• updated unit tests
• updated UPGRADING.md
• add appropriate tag (improvement / bug / etc)
• ready for review

[CLAassistant]

All committers have signed the CLA.

[wasaga]

I'm not sure this is an allowed behaviour, please see kubernetes/kubernetes#119700

[hamzabouissi]

hey @wasaga, thanks for your time, so I inspired the implementation from nginx-ingress code
you can see it here: https://github.com/kubernetes/ingress-nginx/blob/23bd743cedfbc0b2da0365af87cbe0a378df4fcd/internal/ingress/status/status.go#L363

because we were wondering why it was working for inrgess-nginx and not for pomerium

[hamzabouissi]

@wasaga I updated the branch, can you check if everything is good so we can merge it ?

[kralicky]

nit: maybe also check for service type ClusterIP here, like

switch svc.Spec.Type {
case corev1.ServiceTypeLoadBalancer:
  ...
case corev1.ServiceTypeNodePort:
  ...
default:
  return nil
}