Interface down led to a complete outage

[Aymen Frikha]

After installing sunbeam multi-nodes (3 nodes) using only one interface for management and all openstack api networks, I intentionally put one interface of one node down. Right after, I'm not able to use openstack anymore, the dashboard is not accessible and some of the apis like nova doesn't works as well:

- After shutdown an interface on node 09: https://paste.ubuntu.com/p/XN2kFHDq5t/
- using some cli commands works like listing flavors and networks : https://paste.ubuntu.com/p/yCq7KtjHqV/
- trying to list the hypervisors didn't work:
- listing servers doesn't work as well
- here is the output of kubectl get po: https://paste.ubuntu.com/p/797wxkW885/
- Seems that nova api is not reachable anymore: https://paste.ubuntu.com/p/Jv9mhxS5xv/
- after rebooting node 09, everything works fine