parametrized kvm hostnames

Change-Id: Ie799c0596469aa84020cc429d678169ab816e2b0
diff --git a/salt/control/cluster/openstack_gateway_cluster.yml b/salt/control/cluster/openstack_gateway_cluster.yml
index 84c44ac..efc7215 100644
--- a/salt/control/cluster/openstack_gateway_cluster.yml
+++ b/salt/control/cluster/openstack_gateway_cluster.yml
@@ -13,14 +13,14 @@
           engine: virt
           node:
             gtw01:
-              provider: kvm01.${_param:cluster_domain}
+              provider: ${_param:infra_kvm_node01_hostname}.${_param:cluster_domain}
               image: ${_param:salt_control_xenial_image}
               size: openstack.gateway
             gtw02:
-              provider: kvm02.${_param:cluster_domain}
+              provider: ${_param:infra_kvm_node02_hostname}.${_param:cluster_domain}
               image: ${_param:salt_control_xenial_image}
               size: openstack.gateway
             gtw03:
-              provider: kvm03.${_param:cluster_domain}
+              provider: ${_param:infra_kvm_node03_hostname}.${_param:cluster_domain}
               image: ${_param:salt_control_xenial_image}
               size: openstack.gateway