Add openstack_node_role parameter

Add openstack_node_role parameter that will specify node role
primary|secondary. This metadata will be used by formulas as a
trigger to run one-shot operations.

Change-Id: I230590bc5f9d53960c6edaf7e37c44541d9c3342
Related-Prod: PROD-21267
diff --git a/nova/control/single.yml b/nova/control/single.yml
index 07a3b01..4e3799b 100644
--- a/nova/control/single.yml
+++ b/nova/control/single.yml
@@ -11,6 +11,7 @@
           version: latest
   nova:
     controller:
+      role: ${_param:openstack_node_role}
       database:
         host: ${_param:single_address}
       identity: