I have 3 controller nodes and they are gateway nodes also but now I want to add 2 more compute nodes who will have the following flag to handle external port traffic to reply to DHCP for sriov nodes. 

$ ovs-vsctl set open_vswitch . external_ids:ovn-cms-options="enable-chassis-as-extport-host"

How and where do I tell kolla-ansible to put the above option for those 2 new compute nodes so options will survive re-deployment.