There is an issue with kubectl apply and third party resources, so for
the time being we use create for TPRs, but apply for all manifests that
it can handle.
The $KUBECONFIG variable is like $PATH, and supports multiple files
separated by `:`, but --kubeconfig only takes a single file as a value.
Since kubectl picks up the $KUBECONFIG variable already, don't pass it
to kubectl.
Also, use --namespace instead of -n to support older kubectl versions.
It's a lot easier to show and explain the Prometheus config if available
in the standard yaml format. The Kubernetes ConfigMap specs can always
be auto-generated.
This also contains the generated ConfigMaps for the grafana dashboards
as well as for alerts. These will be updated in subsequent changes as
sets of alerts and dashboards are added/updated in the respective
subdirectories in `/assets`.
