Generate random keystone users

Change-Id: I8dbd07b10d29b43d1c35fa76bcaa0f0efb32beda
Related-Prod: PROD-29868
diff --git a/ceilometer/agent/single.yml b/ceilometer/agent/single.yml
index 037bb4e..0bf079f 100644
--- a/ceilometer/agent/single.yml
+++ b/ceilometer/agent/single.yml
@@ -9,6 +9,8 @@
         ssl:
           enabled: ${_param:ceilometer_agent_ssl_enabled}
       identity:
+        user: ${_param:keystone_ceilometer_username}
+        password: ${_param:keystone_ceilometer_password}
         protocol: ${_param:internal_protocol}
       message_queue:
         port: ${_param:openstack_rabbitmq_port}