[stable/prometheus-operator] Create datasource for each Prometheus (#14846)

- Adds ability to create datasource for each Pod of Prometheus
- Uses headless service prometheus-operated which is created by
  Prometheus Operator
- ref:
  https://github.com/coreos/prometheus-operator/blob/0fee93e12dc7c2ea1218f19ae25ec6b893460590/pkg/prometheus/statefulset.go#L255-L286
- Update README.md
- Bump version in Chart.yaml

Signed-off-by: Bhavin Gandhi <bhavin7392@gmail.com>

stable/prometheus-operator/Chart.yaml

@@ -11,7 +11,7 @@ name: prometheus-operator
 sources:
   - https://github.com/coreos/prometheus-operator
   - https://coreos.com/operators/prometheus
-version: 5.18.0
+version: 5.19.0
 appVersion: 0.31.1
 home: https://github.com/coreos/prometheus-operator
 keywords:

stable/prometheus-operator/README.md

@@ -333,7 +333,8 @@ For a full list of configurable values please refer to the [Grafana chart](https
 | `grafana.sidecar.dashboards.enabled` | Enable the Grafana sidecar to automatically load dashboards with a label `{{ grafana.sidecar.dashboards.label }}=1` | `true` |
 | `grafana.sidecar.dashboards.label` | If the sidecar is enabled, configmaps with this label will be loaded into Grafana as dashboards | `grafana_dashboard` |
 | `grafana.sidecar.datasources.enabled` | Enable the Grafana sidecar to automatically load dashboards with a label `{{ grafana.sidecar.datasources.label }}=1` | `true` |
-| `grafana.sidecar.datasources.defaultDatasourceEnabled` | Enable Grafana `Prometheus` default datasource` | `true` |
+| `grafana.sidecar.datasources.defaultDatasourceEnabled` | Enable Grafana `Prometheus` default datasource | `true` |
+| `grafana.sidecar.datasources.createPrometheusReplicasDatasources` | Create datasource for each Pod of Prometheus StatefulSet i.e. `Prometheus-0`, `Prometheus-1` | `false` |
 | `grafana.sidecar.datasources.label` | If the sidecar is enabled, configmaps with this label will be loaded into Grafana as datasources configurations | `grafana_datasource` |
 | `grafana.rbac.pspUseAppArmor` | Enforce AppArmor in created PodSecurityPolicy (requires rbac.pspEnabled) | `true` |
 | `grafana.extraConfigmapMounts` | Additional grafana server configMap volume mounts | `[]` |

stable/prometheus-operator/templates/grafana/configmaps-datasources.yaml

@@ -17,6 +17,15 @@ data:
       url: http://{{ template "prometheus-operator.fullname" . }}-prometheus:9090/{{ trimPrefix "/" .Values.prometheus.prometheusSpec.routePrefix }}
       access: proxy
       isDefault: true
+{{- if .Values.grafana.sidecar.datasources.createPrometheusReplicasDatasources }}
+{{- range until (int .Values.prometheus.prometheusSpec.replicas) }}
+    - name: Prometheus-{{ . }}
+      type: prometheus
+      url: http://prometheus-{{ template "prometheus-operator.fullname" $ }}-prometheus-{{ . }}.prometheus-operated:9090/{{ trimPrefix "/" $.Values.prometheus.prometheusSpec.routePrefix }}
+      access: proxy
+      isDefault: false
+{{- end }}
+{{- end }}
 {{- end }}
 {{- if .Values.grafana.additionalDataSources }}
 {{ toYaml .Values.grafana.additionalDataSources | indent 4}}

stable/prometheus-operator/values.yaml

@@ -411,6 +411,11 @@ grafana:
     datasources:
       enabled: true
       defaultDatasourceEnabled: true
+      ## Create datasource for each Pod of Prometheus StatefulSet;
+      ## this uses headless service `prometheus-operated` which is
+      ## created by Prometheus Operator
+      ## ref: https://git.io/fjaBS
+      createPrometheusReplicasDatasources: false
       label: grafana_datasource
 
   extraConfigmapMounts: []