Glance: make PV flexible

This PS makes the PV used for the file backend flexible, allowing
operators to specify the annotation and size used/allocated.

Change-Id: I6d153143f9cc268c4c543e392ddf115e5db67a57

glance/templates/pvc-images.yaml

@@ -18,10 +18,10 @@ apiVersion: v1
 metadata:
   name: glance-images
   annotations:
-    volume.beta.kubernetes.io/storage-class: general
+    {{ .Values.volume.class_path }}: {{ .Values.volume.class_name }}
 spec:
   accessModes: [ "ReadWriteOnce" ]
   resources:
     requests:
-      storage: 20Gi
+      storage: {{ .Values.volume.size }}
 {{- end }}

glance/values.yaml

@@ -152,6 +152,11 @@ ceph:
   # common/secrets/ceph-client-key
   glance_keyring: null
 
+volume:
+  class_path: volume.beta.kubernetes.io/storage-class
+  class_name: general
+  size: 2Gi
+
 misc:
   workers: 8
   debug: false