Allow qpid to be selected as AMQP provider on precise

Fixes bug 1137667

Previously the auth/sasl config for qpidd was broken, and the
openstack services using RPC were not properly configured.

Now we ensure that:

- the admin qpid_username/password are configured for all services
  (as the qpidd ACL config denies all access to non-admin users)

- the PLAIN sasl mechanism is configured for qpidd (otherwise the
  qpid_password is not propogated)

- the qpidd process has read permission on the sasl DB (otherwise
  thw admin user/apss cannot be verified even if set)

Change-Id: Id6bd675841884451b78f257afe786f494a03c0f7
diff --git a/lib/ceilometer b/lib/ceilometer
index e890ff9..8772867 100644
--- a/lib/ceilometer
+++ b/lib/ceilometer
@@ -64,13 +64,7 @@
     [ ! -d $CEILOMETER_API_LOG_DIR ] &&  sudo mkdir -m 755 -p $CEILOMETER_API_LOG_DIR
     sudo chown $USER $CEILOMETER_API_LOG_DIR
 
-    if is_service_enabled rabbit ; then
-        iniset $CEILOMETER_CONF DEFAULT rpc_backend 'ceilometer.openstack.common.rpc.impl_kombu'
-        iniset $CEILOMETER_CONF DEFAULT rabbit_host $RABBIT_HOST
-        iniset $CEILOMETER_CONF DEFAULT rabbit_password $RABBIT_PASSWORD
-    elif is_service_enabled qpid ; then
-        iniset $CEILOMETER_CONF DEFAULT rpc_backend 'ceilometer.openstack.common.rpc.impl_qpid'
-    fi
+    iniset_rpc_backend ceilometer $CEILOMETER_CONF DEFAULT
 
     iniset $CEILOMETER_CONF DEFAULT notification_topics 'notifications,glance_notifications'
     iniset $CEILOMETER_CONF DEFAULT verbose True