Configure external Prometheus to scrape metrics from MKE

Configure external Prometheus to scrape metrics from MKE

To configure your external Prometheus server to scrape metrics from Prometheus in MKE:

  1. Source an admin bundle.

  2. Create a Kubernetes secret that contains your bundle TLS material.

    (cd $DOCKER_CERT_PATH && kubectl create secret generic prometheus --from-file=ca.pem --from-file=cert.pem --from-file=key.pem)
    
  3. Create a Prometheus deployment and ClusterIP service using YAML.

    On AWS with the Kubernetes cloud provider configured:

    1. Replace ClusterIP with LoadBalancer in the service YAML.

    2. Access the service through the load balancer.

    3. If you run Prometheus external to MKE, change the domain for the inventory container in the Prometheus deployment from ucp-controller.kube-system.svc.cluster.local to an external domain, to access MKE from the Prometheus node.

    kubectl apply -f - <<EOF
    apiVersion: v1
    kind: ConfigMap
    metadata:
      name: prometheus
    data:
      prometheus.yaml: |
        global:
          scrape_interval: 10s
        scrape_configs:
        - job_name: 'ucp'
          tls_config:
            ca_file: /bundle/ca.pem
            cert_file: /bundle/cert.pem
            key_file: /bundle/key.pem
            server_name: proxy.local
          scheme: https
          file_sd_configs:
          - files:
            - /inventory/inventory.json
    ---
    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: prometheus
    spec:
      replicas: 2
      selector:
        matchLabels:
          app: prometheus
      template:
        metadata:
          labels:
            app: prometheus
        spec:
          containers:
          - name: inventory
            image: alpine
            command: ["sh", "-c"]
            args:
            - apk add --no-cache curl &&
              while :; do
                curl -Ss --cacert /bundle/ca.pem --cert /bundle/cert.pem --key /bundle/key.pem --output /inventory/inventory.json https://ucp-controller.kube-system.svc.cluster.local/metricsdiscovery;
                sleep 15;
              done
            volumeMounts:
            - name: bundle
              mountPath: /bundle
            - name: inventory
              mountPath: /inventory
          - name: prometheus
            image: prom/prometheus
            command: ["/bin/prometheus"]
            args:
            - --config.file=/config/prometheus.yaml
            - --storage.tsdb.path=/prometheus
            - --web.console.libraries=/etc/prometheus/console_libraries
            - --web.console.templates=/etc/prometheus/consoles
            volumeMounts:
            - name: bundle
              mountPath: /bundle
            - name: config
              mountPath: /config
            - name: inventory
              mountPath: /inventory
          volumes:
          - name: bundle
            secret:
              secretName: prometheus
          - name: config
            configMap:
              name: prometheus
          - name: inventory
            emptyDir:
              medium: Memory
    ---
    apiVersion: v1
    kind: Service
    metadata:
      name: prometheus
    spec:
      ports:
      - port: 9090
        targetPort: 9090
      selector:
        app: prometheus
      sessionAffinity: ClientIP
    EOF
    
  4. Determine the service ClusterIP:

    $ kubectl get service prometheus
    
    NAME         TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)    AGE
    prometheus   ClusterIP   10.96.254.107   <none>        9090/TCP   1h
    
  5. Forward port 9090 on the local host to the ClusterIP. The tunnel you create does not need to be kept alive as its only purpose is to expose the Prometheus UI.

    ssh -L 9090:10.96.254.107:9090 ANY_NODE
    
  6. Visit http://127.0.0.1:9090 to explore the MKE metrics that Prometheus is collecting.