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/barbican/server/cluster.yml b/barbican/server/cluster.yml
index ed45b47..d8b570c 100644
--- a/barbican/server/cluster.yml
+++ b/barbican/server/cluster.yml
@@ -6,5 +6,6 @@
     cluster_internal_protocol: 'http'
   barbican:
     server:
+      role: ${_param:openstack_node_role}
       identity:
         protocol: ${_param:cluster_internal_protocol}