Attempt to fix k8s-ha-contrail

Change-Id: I4b5a50ee2edcf2d18282bc7dd8da2f4133b5d3bb
diff --git a/classes/cluster/k8s-ha-contrail/infra/config.yml b/classes/cluster/k8s-ha-contrail/infra/config.yml
index 3d7cbd0..d439773 100644
--- a/classes/cluster/k8s-ha-contrail/infra/config.yml
+++ b/classes/cluster/k8s-ha-contrail/infra/config.yml
@@ -1,11 +1,12 @@
 classes:
+- system.linux.system.single
 - system.linux.system.repo.ubuntu
 - system.linux.system.repo.mcp.salt
 - system.openssh.client.lab
 - system.salt.master.pkg
-- system.salt.minion.ca.salt_master
 - system.salt.master.api
 - system.reclass.storage.salt
+- system.salt.minion.ca.salt_master
 - system.salt.minion.cert.k8s_server
 - system.reclass.storage.system.kubernetes_control_cluster
 - system.reclass.storage.system.opencontrail_control_cluster
@@ -35,6 +36,15 @@
           proto: static
           address: ${_param:single_address}
           netmask: 255.255.255.0
+          pre_up_cmds:
+          - "iptables -t nat -A POSTROUTING -o ens3 -j MASQUERADE"
+          post_down_cmds:
+          - "iptables -t nat -F POSTROUTING"
+    system:
+      kernel:
+        sysctl:
+          net.ipv4.conf.ens3.forwarding: 1
+          net.ipv4.conf.ens3.send_redirects: 0
   reclass:
     storage:
       class_mapping: