Add support for Ceph monitoring

This change adds support for Ceph monitoring:
- service.monitoring.cluster_stats is applied to monitoring nodes for
  collecting cluster-wide metrics (through the Ceph CLI).
- service.monitoring.node_stats is applied to the Ceph nodes for
  collecting monitor and OSD metrics (through Unix sockets).

Because Telegraf runs as a container on the monitoring nodes and
requires a working Ceph client configuration, this  change also adds
support for deploying Ceph client in container mode.

Change-Id: If7359aca34a350f2c8ee2251bbe8a85314550a45
diff --git a/metadata/service/monitoring/node_stats.yml b/metadata/service/monitoring/node_stats.yml
new file mode 100644
index 0000000..4462309
--- /dev/null
+++ b/metadata/service/monitoring/node_stats.yml
@@ -0,0 +1,9 @@
+applications:
+- ceph
+classes:
+- service.ceph.support
+parameters:
+  ceph:
+    monitoring:
+      node_stats:
+        enabled: true