update /etc/hosts and system level

Change-Id: If14e63ad26c5a3fc915680c8e3569dfba526297a
diff --git a/classes/cluster/virtual-mcp11-k8s-contrail/kubernetes/init.yml b/classes/cluster/virtual-mcp11-k8s-contrail/kubernetes/init.yml
index e404760..51aeacd 100644
--- a/classes/cluster/virtual-mcp11-k8s-contrail/kubernetes/init.yml
+++ b/classes/cluster/virtual-mcp11-k8s-contrail/kubernetes/init.yml
@@ -75,6 +75,7 @@
 
   linux:
     network:
+      purge_hosts: true
       host:
         ctl:
           address: ${_param:kubernetes_control_address}