CORD-382 updated compute node provisioning so that the specification of fabric NIC identification is passed on

Change-Id: Ibf596d610f5420f9a9ead7ce3a6f93d022ad85ac
(cherry picked from commit 2e76f122660da12e5fdad5d58be52d9d4fe871c3)
diff --git a/roles/head-node/files/compute-node.yml b/roles/head-node/files/compute-node.yml
index 7fb41f0..94aac38 100644
--- a/roles/head-node/files/compute-node.yml
+++ b/roles/head-node/files/compute-node.yml
@@ -1,4 +1,12 @@
-- hosts: all
+---
+- name: Include vars
+  hosts: all
+  tasks:
+  - include_vars: vars/compute-node.yml
+
+- name: Configure compute hosts to use DNS server
+  hosts: all
   remote_user: ubuntu
+  become: yes
   roles:
-    - compute-node
+    - role: compute-node