[stable/prometheus-postgres-exporter] add support for Google Cloud SQL (#6009)

* add support for Google Cloud SQL

Cloud SQL, Google's managed database product, requires use of an authentication
proxy when accessed from dynamic IPs. To limit access to the proxy, it is
recommended to use a sidecar.
More info: https://cloud.google.com/sql/docs/postgres/connect-kubernetes-engine

Cloud SQL, like other managed databases, does not allow use of
superuser accounts. Therefore, add support for a configurable
database in `datasource`.
More info: https://github.com/wrouesnel/postgres_exporter#running-as-non-superuser

* re-bump chart version

* use extraContainers & extraVolumes

stable/prometheus-postgres-exporter/Chart.yaml

@@ -2,7 +2,7 @@ apiVersion: v1
 appVersion: "0.4.6"
 description: A Helm chart for prometheus postgres-exporter
 name: prometheus-postgres-exporter
-version: 0.3.0
+version: 0.4.0
 home: https://github.com/wrouesnel/postgres_exporter
 sources:
 - https://github.com/wrouesnel/postgres_exporter

stable/prometheus-postgres-exporter/README.md

@@ -55,6 +55,8 @@ The following table lists the configurable parameters of the postgres Exporter c
 | `nodeSelector`                    | node labels for pod assignment | `{}`  |
 | `affinity`                       |     node/pod affinities | `{}` |
 | `annotations`                    | Deployment annotations | `{}` |
+| `extraContainers`                | Additional sidecar containers | `""` |
+| `extraVolumes`                   | Additional volumes for use in extraContainers | `""` |
 
 
 Specify each parameter using the `--set key=value[,key=value]` argument to `helm install`. For example,

stable/prometheus-postgres-exporter/templates/deployment.yaml

@@ -29,7 +29,7 @@ spec:
         - name: {{ .Chart.Name }}
           args:
           - "--extend.query-path=/etc/config.yaml"
-          env:          
+          env:
             - name: DATA_SOURCE_NAME
               valueFrom:
                 secretKeyRef:
@@ -55,6 +55,9 @@ spec:
             - name: queries
               mountPath: /etc/config.yaml
               subPath: config.yaml
+{{- with .Values.extraContainers }}
+{{ tpl . $ | indent 8 }}
+{{- end }}
      {{- with .Values.nodeSelector }}
       nodeSelector:
 {{ toYaml . | indent 8 }}
@@ -71,4 +74,7 @@ spec:
       - configMap:
           defaultMode: 420
           name: {{ template "prometheus-postgres-exporter.fullname" . }}
-        name: queries
+        name: queries
+{{- with .Values.extraVolumes }}
+{{ tpl . $ | indent 6 }}
+{{- end }}

stable/prometheus-postgres-exporter/templates/secrets.yaml

@@ -9,4 +9,4 @@ metadata:
     release: {{ .Release.Name }}
 type: Opaque
 data:
-  data_source_name: "{{ printf "postgresql://%s:%s@%s:%s/?sslmode=%s" .Values.config.datasource.user .Values.config.datasource.password .Values.config.datasource.host  .Values.config.datasource.port .Values.config.datasource.sslmode | b64enc }}"
+  data_source_name: "{{ printf "postgresql://%s:%s@%s:%s/%s?sslmode=%s" .Values.config.datasource.user .Values.config.datasource.password .Values.config.datasource.host  .Values.config.datasource.port .Values.config.datasource.database .Values.config.datasource.sslmode | b64enc }}"

stable/prometheus-postgres-exporter/values.yaml

@@ -44,6 +44,7 @@ config:
     user:
     password:
     port: "5432"
+    database: ''
     sslmode: disable
   # this are the defaults queries that the exporter will run, extracted from: https://github.com/wrouesnel/postgres_exporter/blob/master/queries.yaml
   queries: |-
@@ -145,3 +146,9 @@ tolerations: []
 affinity: {}
 
 annotations: {}
+
+# Additional sidecar containers, e. g. for a database proxy, such as Google's cloudsql-proxy
+extraContainers: |
+
+# Additional volumes, e. g. for secrets used in an extraContainer
+extraVolumes: |