Add cluster_name support for run-kiali.sh hack script

[jshaughn]

run-kiali.sh is not working well if Istio is installed with an unset cluster name. In this scenario I had to locally update hack/run-kiali-config-template.yaml with:

kubernetes_config:
  cluster_name: "Kubernetes"

run-kiali.sh should handle the default cluster name scenario, or be configurable.

[nrfox]

I wonder if this should actually be a change in how we handle "remote cluster" deployments: https://github.com/kiali/kiali/#observing-a-remote-cluster. Is it the kiali config cluster name that is unset or the istio cluster name? iirc when the istio cluster name is unset it will default to Kubernetes. You should see that in metrics for source_cluster and destination_cluster for example.

[jshaughn]

I think what is happening is we may be querying Istio itself and it is probably returning an empty cluster_name. In general we, Kiali, then default to "Kubernetes" (as does Istio for things like telemetry), but for this run-kiali scenario we were not inserting the default. Setting the variable is working, though.

[nrfox]

I think what is happening is we may be querying Istio itself and it is probably returning an empty cluster_name. In general we, Kiali, then default to "Kubernetes" (as does Istio for things like telemetry), but for this run-kiali scenario we were not inserting the default. Setting the variable is working, though.

That sounds like a bug then. We should still be able to detect the cluster name even when running outside the cluster and we should still default to Kubernetes when we can't. Kiali "detects the cluster name" by looking at the istiod deployment and looking for a CLUSTER_ID env var. From what I've seen, this still gets set even when you do not provide a value for cluster id in the mesh config.