add initContainer to copy config from ConfigMap (#4169)

* Update statefulset.yaml

ConfigMaps are read-only since Kubernetes 1.9.4 (https://github.com/kubernetes/kubernetes/pull/58720). The rabbitmq-ha Chart uses a ConfigMap to provision /etc/rabbitmq. The official RabbitMQ docker image modifies these files in its docker-entrypoint.sh. This PR adds an initContainer to the StatefulSet to copy the configs from the ConfigMap to a new emptyDir volume.

* Update Chart.yaml

Bump version

* Update statefulset.yaml

stable/rabbitmq-ha/Chart.yaml

@@ -1,7 +1,7 @@
 name: rabbitmq-ha
 apiVersion: v1
 appVersion: 3.7.3
-version: 1.0.2
+version: 1.0.3
 description: Highly available RabbitMQ cluster, the open source message broker
   software that implements the Advanced Message Queuing Protocol (AMQP).
 keywords:

stable/rabbitmq-ha/templates/statefulset.yaml

@@ -24,6 +24,15 @@ spec:
     spec:
       terminationGracePeriodSeconds: 10
       serviceAccountName: {{ template "rabbitmq-ha.serviceAccountName" . }}
+      initContainers:
+        - name: copy-rabbitmq-config
+          image: busybox
+          command: ['sh', '-c', 'cp /configmap/* /etc/rabbitmq']
+          volumeMounts:
+            - name: configmap
+              mountPath: /configmap
+            - name: config
+              mountPath: /etc/rabbitmq
       containers:
         - name: {{ .Chart.Name }}
           image: {{ .Values.image.repository }}:{{ .Values.image.tag }}
@@ -154,6 +163,8 @@ spec:
       {{- end }}
       volumes:
         - name: config
+          emptyDir: {}
+        - name: configmap
           configMap:
             name: {{ template "rabbitmq-ha.fullname" . }}
         {{- if .Values.rabbitmqCert.enabled }}