title: postgres on kubernetes volume permission error
body: <p>I'm trying to deploy postgres/postgis on GKE, but I continue to get the permission error: <code>initdb: could not change permissions of directory "/var/lib/postgresql/data": Operation not permitted</code>. I've tried various fixes that I've researched but I've yet to get passed this error. Below is my deployment yaml.</p>
  
  <p>What am I missing?</p>
  
  <pre><code>apiVersion: extensions/v1beta1
  kind: Deployment
  metadata:
    name: postgres
  spec:
    replicas: 1
    template:
      metadata:
        labels:
          app: postgres
      spec:
        terminationGracePeriodSeconds: 10
        securityContext:
          runAsUser: 1000
          fsGroup: 1000
        containers:
          - name: postgres
            image: mdillon/postgis:10
            imagePullPolicy: "IfNotPresent"
            ports:
              - containerPort: 5432
            env:
              - name: POSTGRES_DB
                value: "database"
              - name: POSTGRES_USER
                value: "postgres"
              - name: POSTGRES_PASSWORD
                value: "postgres"
            volumeMounts:
              - name: postgredb
                mountPath: /var/lib/postgresql/data
                subPath: data
        volumes:
          - name: postgredb
            persistentVolumeClaim:
              claimName: postgres-pvc
  </code></pre>