Juju deploy to Ussuri Openstack cloud fails to allocate floating IP to instance

I’m doing some test on the Ussuri build and I’ve run into a weird issue.

When I deploy units to a model backed by an Ussuri Openstack cloud the controller fails to allocate a Public IP to the instance. What’s weird is that the retry submits a brand new request to Openstack and builds a new instance, leaving the ‘old’ one behind. If I leave it to run, after a while I exhaust my instance quota on the project.

juju add-model basic-opentack-test openstack.lab.devzero.home/RegionOne
juju model-config network=f962b3e3-fc28-4d97-8b93-3e9f147b6507
juju model-config use-floating-ip=true
root@maas-01:~# juju status
Model                Controller                Cloud/Region                          Version  SLA          Timestamp
basic-opentack-test  lab.devzero.home-default  openstack.lab.devzero.home/RegionOne  2.8.1    unsupported  22:20:12Z

App     Version  Status   Scale  Charm   Store       Rev  OS      Notes
ubuntu           waiting    0/1  ubuntu  jujucharms   15  ubuntu

Unit      Workload  Agent       Machine  Public address  Ports  Message
ubuntu/0  waiting   allocating  0                               waiting for machine

Machine  State    DNS  Inst id  Series  AZ  Message
0        pending       pending  focal       failed to start machine 0 (cannot allocate a public IP as needed: could not find an external network in availability zone [] not found), retrying in 10s (4 more attempts)


root@maas-01:~# openstack server list --insecure
+--------------------------------------+-----------------------------------+--------+----------------------------------------+--------------------------------------------------------------+--------+
| ID                                   | Name                              | Status | Networks                               | Image                                                        | Flavor |
+--------------------------------------+-----------------------------------+--------+----------------------------------------+--------------------------------------------------------------+--------+
| 68843c96-3103-455c-aaf8-a19cdc32efd4 | juju-983ed7-basic-opentack-test-0 | ACTIVE | Admin-Internal-Network=192.168.200.230 | auto-sync/ubuntu-focal-20.04-amd64-server-20200907-disk1.img | L1     |
| 7a2bdeda-0600-4221-841e-1f1e86207b51 | juju-983ed7-basic-opentack-test-0 | ACTIVE | Admin-Internal-Network=192.168.200.165 | auto-sync/ubuntu-focal-20.04-amd64-server-20200907-disk1.img | L1     |
| e0fd8b2a-c2d6-437f-84d8-93e8e2f79dfa | juju-983ed7-basic-opentack-test-0 | ACTIVE | Admin-Internal-Network=192.168.200.135 | auto-sync/ubuntu-focal-20.04-amd64-server-20200907-disk1.img | L1     |
| 849b700c-4674-47cc-8333-2f21b6a581cb | juju-983ed7-basic-opentack-test-0 | ACTIVE | Admin-Internal-Network=192.168.200.191 | auto-sync/ubuntu-focal-20.04-amd64-server-20200907-disk1.img | L1     |
| 82ad2fd3-accb-4421-95d0-4dbf423f88a7 | juju-983ed7-basic-opentack-test-0 | ACTIVE | Admin-Internal-Network=192.168.200.58  | auto-sync/ubuntu-focal-20.04-amd64-server-20200907-disk1.img | L1     |
| 90f2665d-af9c-4e4f-90f1-5d0788b48b39 | juju-983ed7-basic-opentack-test-0 | ACTIVE | Admin-Internal-Network=192.168.200.101 | auto-sync/ubuntu-focal-20.04-amd64-server-20200907-disk1.img | L1     |
| 3b5402ae-40c5-413d-996b-a58699e72d07 | juju-983ed7-basic-opentack-test-0 | ACTIVE | Admin-Internal-Network=192.168.200.118 | auto-sync/ubuntu-focal-20.04-amd64-server-20200907-disk1.img | L1     |
| f563d290-a648-4cb4-ad00-f855077bfa00 | juju-983ed7-basic-opentack-test-0 | ACTIVE | Admin-Internal-Network=192.168.200.219 | auto-sync/ubuntu-focal-20.04-amd64-server-20200907-disk1.img | L1     |
| d82c24a4-2abd-4c8a-8c35-f26d67857c9e | juju-983ed7-basic-opentack-test-0 | ACTIVE | Admin-Internal-Network=192.168.200.131 | auto-sync/ubuntu-focal-20.04-amd64-server-20200907-disk1.img | L1     |
+--------------------------------------+-----------------------------------+--------+----------------------------------------+--------------------------------------------------------------+--------+
root@maas-01:~#

Here’s the network config for the external network.