add missing region param
diff --git a/ceilometer/agent/cluster.yml b/ceilometer/agent/cluster.yml
index d4ec5da..cfd93f7 100644
--- a/ceilometer/agent/cluster.yml
+++ b/ceilometer/agent/cluster.yml
@@ -3,6 +3,7 @@
 parameters:
   ceilometer:
     agent:
+      region: ${_param:openstack_region}
       enabled: true
       version: ${_param:ceilometer_version}
       secret: ${_param:ceilometer_secret_key}