Expose Operator metrics

When specified for a resource, the following ProxyClass definition enables client metrics at the path /metrics on a container port named "metrics":

apiVersion: tailscale.com/v1alpha1
kind: ProxyClass
metadata:
  name: prod
spec:
  metrics:
    enable: true

The operator also creates a metrics Service for the proxy in the operator's namespace that also exposes metrics at /metrics on a port named "metrics".

Prometheus ServiceMonitor

The Kubernetes operator can also create a Prometheus ServiceMonitor for proxy resources.

To enable it:

1. Ensure that Prometheus operator including its custom resource definitions is installed.

2. Apply ProxyClass that enables metrics and ServiceMonitor creation:

   apiVersion: tailscale.com/v1alpha1
   kind: ProxyClass
   metadata:
     name: prod
   spec:
     metrics:
       enable: true
       serviceMonitor:
         enable: true
   

The ingested metrics have labels that identify the proxy to which the ProxyClass was applied:

• ts_proxy_type: Type of the proxy. Values can be ingress_service, ingress_resource, connector or proxygroup.
• ts_proxy_parent_name: Name of the proxy's parent resource. That is, name of the Ingress resource, Tailscale Service, Connector or ProxyGroup.
• ts_proxy_parent_namespace: Namespace of the proxy's parent resource. This only applies to namespaced resources.