Feat/Unify grafana-operator based setup on k8s/openshift overlays

[slopezz]

Until now, grafana (part of observability-hub) had a different setup on k8s and openshift:

• Openshift: it was used the grafana-operator (simple to maintain)
• K8s: it was used a "manual" deployment, which make difficult to manage the app lifecycle, as there are dozens of related k8s resources with lots of "manual" volume mounts, rbac running... too complex

This PR:

• Unifies the grafana setup by using the same community grafana-operator
  • Grafana main setup is done on the kustomized base, while the small differences are managed on each overlay:
    • small differences on Subscription
    • very similar Grafana CR (with some proxy tuning in the case of openshift)
    • complete different GrafanaDatasource
• Kuadrant grafana dashboards are obtained directly through an URL (so no need to create an intermediate configmap mounted on the GrafanaDashboard CR)
  • Also, I updated to newer release v1.0.2
• Istio dashboard was only present in k8s overlay (not openshift). What I did is to add it to the base (so it is always present on any overlay).
  • I cleaned the dashboard json by removing harcoded prometheus datasource ID
  • It is created a configmap, and then mounted on a GrafanaDashboard CR (the same approach it was used already on openshift overlay). I wonder if this dashboard should go to https://github.com/Kuadrant/kuadrant-operator/tree/main/examples/dashboards (like the rest of the dashboards)
• k8s grafana overlay exposes grafana service with a LoadBalancer, so using the same MetalLB already used for ArgoCD, making easier the usage of Grafana UI with no need of port-forwarding...
  • A new make target called grafana-url provide the Grafana MetalLB URL with user/password
• Enable openshift user-workload-monitoring on openshift overlay (grafana-operator already has thanos as the datasource, consolidating cluster and uwm prometheus instances), so we have gateway metrics available in the dashboard

[roivaz]

Tested both in k8s and OCP4 and both work as expected.

[david-martin]

Thanks for taking the time to make this change @slopezz