expose-harvester-prometheus-data-source.md

Expose Harvester Prometheus Http Datasource

You plan to expose the Harvester prometheus datasource from the embedded rancher-monitoring stack.

:::note

Sugguest to use a new IP (not Harvester VIP, not any NODE IP) for exposing the prometheus data source, to avoid affection other services.

The current solution exposes only via http endpoint.

Enable the rancher-monitoring addon on Harvester.

:::

Prepare a new Serivce

Prepare a new Loadbalancer type k8s service to expose the Prometheus.

When the LB is getting IP from DHCP server:

cat > prometheus.yaml << 'EOF'
apiVersion: v1
kind: Service
metadata:
  name: prometheus-expose
  namespace: cattle-monitoring-system
spec:
  ipFamilies:
  - IPv4
  ipFamilyPolicy: SingleStack
  loadBalancerIP: 0.0.0.0
  ports:
  - name: promethues-http
    port: 9090
    protocol: TCP
    targetPort: 9090
  selector:
    app.kubernetes.io/name: prometheus
  sessionAffinity: None
  type: LoadBalancer
EOF

kubectl apply -f prometheus.yaml

If you are using fixed IP for this LB, change the field loadBalancerIP.

Change

spec:
  loadBalancerIP: 0.0.0.0
  
to

spec:
  loadBalancerIP: your IP  

Verify the service

A successful run will get:

$ kubectl get service -n cattle-monitoring-system prometheus-expose
NAME                TYPE           CLUSTER-IP     EXTERNAL-IP       PORT(S)          AGE
prometheus-expose   LoadBalancer   10.53.162.14   192.168.122.138   9090:30517/TCP   3m47s


$ kubectl get endpointslice -n cattle-monitoring-system  -l "kubernetes.io/service-name"=prometheus-expose
NAME                      ADDRESSTYPE   PORTS   ENDPOINTS     AGE
prometheus-expose-mm7bd   IPv4          9090    10.52.0.144   4m54s

Verify the datasource

Access the metrics from http endpoint.

http://192.168.122.138:9090/metrics