set dns servers in infra-init

Change-Id: I114621b88e71b6e85d00465f9a200e31f6684e1c
diff --git a/classes/cluster/virtual-mcp11-k8s-calico/infra/init.yml b/classes/cluster/virtual-mcp11-k8s-calico/infra/init.yml
index adbc05c..20e53e3 100644
--- a/classes/cluster/virtual-mcp11-k8s-calico/infra/init.yml
+++ b/classes/cluster/virtual-mcp11-k8s-calico/infra/init.yml
@@ -25,6 +25,10 @@
     apt_mk_version: nightly
   linux:
     network:
+      resolv:
+        dns:
+          - 172.18.176.4
+          - 172.18.176.7
       host:
         cfg01:
           address: ${_param:infra_config_address}