grafana: Use declarative data sources

grafana/application.yml

@@ -22,6 +22,22 @@ spec:
 ---
 apiVersion: v1
 kind: ConfigMap
+metadata:
+  name: grafana-datasources
+data:
+  prometheus.yaml: |
+    apiVersion: 1
+    prune: true
+    datasources:
+      - name: Prometheus
+        type: prometheus
+        orgId: 1
+        url: http://prometheus-operated.monitoring.svc.cluster.local:9090
+        version: 1
+        editable: false
+---
+apiVersion: v1
+kind: ConfigMap
 metadata:
   name: grafana-config
 data:
@@ -152,10 +168,15 @@ spec:
               name: grafana-data
             - mountPath: /etc/grafana
               name: grafana-config
+            - mountPath: /etc/grafana/provisioning/datasources
+              name: grafana-datasources
       volumes:
         - name: grafana-config
           configMap:
             name: grafana-config
+        - name: grafana-datasources
+          configMap:
+            name: grafana-datasources
   volumeClaimTemplates:
     - metadata:
         name: grafana-data