grains / crush / auto generate keyrings

Change-Id: I380d2d0dad799da0b1cc55b16517402b60421a30
diff --git a/metadata/service/mon/single.yml b/metadata/service/mon/single.yml
index da43193..8be5da5 100644
--- a/metadata/service/mon/single.yml
+++ b/metadata/service/mon/single.yml
@@ -9,13 +9,13 @@
       enabled: true
       keyring:
         mon:
-          key: ${_param:ceph_mon_keyring}
           caps:
             mon: "allow *"
+    common:
+      keyring:
         admin:
-          key: ${_param:ceph_admin_keyring}
           caps:
             mds: "allow *"
             mgr: "allow *"
             mon: "allow *"
-            osd: "allow *"
\ No newline at end of file
+            osd: "allow *"