Traefik metrics in latest K3s

[fabltd]

Hi

It seems k3s version v1.21.1+k3s1 that uses Traefik V 2.4.8 does not by default have metrics enabled.

Trying to track down how to make the configuration change.

[jeanpommier]

Hi @fabltd
I don't know if you found out since then. For the records:

You have to activate the metrics.

It can be done by creating a yaml file in /var/lib/rancher/k3s/server/manifests on the control-plane server, with the following content

apiVersion: helm.cattle.io/v1
kind: HelmChartConfig
metadata:
  name: traefik
  namespace: kube-system
spec:
  valuesContent: |-
    additionalArguments:
      - '--metrics.prometheus=true'
      - '--metrics.prometheus.entryPoint=metrics'
    ports:
      metrics:
        port: 8082

It is deployed automatically by k3s.

Then you'll have to deploy a service exposing the metrics, and the corresponding serviceMonitor.
I'm using the following config:

• traefik-metrics-svc.yaml:

  apiVersion: v1
  kind: Service
  metadata:
    name: traefik-metrics-service
    labels:
      app: traefik-metrics
    namespace: kube-system
  spec:
    selector:
      app.kubernetes.io/name: traefik
    ports:
    - name: metrics
      port: 8082
  

• traefik-servicemonitor.yaml:

  apiVersion: monitoring.coreos.com/v1
  kind: ServiceMonitor
  metadata:
    labels:
      app: traefik
      release: prometheus
    name: traefik
  spec:
    endpoints:
    - port: metrics
    namespaceSelector:
      matchNames:
      - kube-system
    selector:
      matchLabels:
        app: traefik-metrics