postgresql: optional prometheus metrics exporter (#260)

* postgresql: optional prometheus metrics exporter

* split metrics.image into image and imageTag

* bump postgresql chart to 0.3.0

* Adding myself as maintainer for the postgresql chart

stable/postgresql/Chart.yaml

@@ -1,5 +1,5 @@
 name: postgresql
-version: 0.2.2
+version: 0.3.0
 description: Chart for PostgreSQL
 keywords:
 - postgresql
@@ -12,4 +12,5 @@ sources:
 - https://github.com/docker-library/postgres
 maintainers:
 - name: swordbeta
+- name: databus23
 engine: gotpl

stable/postgresql/README.md

@@ -56,6 +56,11 @@ The following tables lists the configurable parameters of the PostgresSQL chart
 | `persistence.accessMode`   | Use volume as ReadOnly or ReadWrite        | `ReadWriteOnce`                                            |
 | `persistence.size`         | Size of data volume                        | `8Gi`                                                      |
 | `resources`                | CPU/Memory resource requests/limits        | Memory: `256Mi`, CPU: `100m`                               |
+| `metrics.enabled`          | Start a side-car prometheus exporter       | `false`                                                    |
+| `metrics.image`            | Exporter image                             | `wrouesnel/postgres_exporter`                              |
+| `metrics.imageTag`         | Exporter image                             | `v0.1.1`                                                   |
+| `metrics.imagePullPolicy`  | Exporter image pull policy                 | `IfNotPresent`                                             |
+| `metrics.resources`        | Exporter resource requests/limit           | Memory: `256Mi`, CPU: `100m`                               |
 
 The above parameters map to the env variables defined in [postgres](http://github.com/docker-library/postgres). For more information please refer to the [postgres](http://github.com/docker-library/postgres) image documentation.
 
@@ -82,3 +87,6 @@ $ helm install --name my-release -f values.yaml stable/postgresql
 The [postgres](https://github.com/docker-library/postgres) image stores the PostgreSQL data and configurations at the `/var/lib/postgresql/data/pgdata` path of the container.
 
 The chart mounts a [Persistent Volume](http://kubernetes.io/docs/user-guide/persistent-volumes/) volume at this location. The volume is created using dynamic volume provisioning.
+
+## Metrics
+The chart optionally can start a metrics exporter for [prometheus](https://prometheus.io). The metrics endpoint (port 9187) is not exposed and it is expected that the metrics are collected from inside the k8s cluster using something similar as the described in the [example Prometheus scrape configuration](https://github.com/prometheus/prometheus/blob/master/documentation/examples/prometheus-kubernetes.yml).

stable/postgresql/templates/deployment.yaml

@@ -67,6 +67,19 @@ spec:
         volumeMounts:
         - name: data
           mountPath: /var/lib/postgresql/data/pgdata
+{{- if .Values.metrics.enabled }}
+      - name: metrics 
+        image: "{{ .Values.metrics.image }}:{{ .Values.metrics.imageTag }}"
+        imagePullPolicy: {{ default "" .Values.metrics.imagePullPolicy | quote }}
+        env:
+        - name: DATA_SOURCE_NAME
+          value: postgresql://postgres@localhost:5432?sslmode=disable
+        ports:
+        - name: metrics
+          containerPort: 9187
+        resources:
+{{ toYaml .Values.metrics.resources | indent 10 }}
+{{- end }}
       volumes:
       - name: data
       {{- if .Values.persistence.enabled }}

stable/postgresql/templates/svc.yaml

@@ -7,6 +7,11 @@ metadata:
     chart: "{{ .Chart.Name }}-{{ .Chart.Version }}"
     release: "{{ .Release.Name }}"
     heritage: "{{ .Release.Service }}"
+{{- if .Values.metrics.enabled }}
+  annotations:
+    prometheus.io/scrape: "true"
+    prometheus.io/port: "9187"
+{{- end }}
 spec:
   ports:
   - name: postgresql

stable/postgresql/values.yaml

@@ -28,6 +28,16 @@ persistence:
   accessMode: ReadWriteOnce
   size: 8Gi
 
+metrics:
+  enabled: false
+  image: wrouesnel/postgres_exporter
+  imageTag: v0.1.1
+  imagePullPolicy: IfNotPresent
+  resources:
+    requests:
+      memory: 256Mi
+      cpu: 100m
+
 ## Configure resource requests and limits
 ## ref: http://kubernetes.io/docs/user-guide/compute-resources/
 ##