Comment 2 for bug 1915727

Yes, you're right. So what I basically have is an inventory modelled on this:

https://docs.openstack.org/kayobe/latest/configuration/reference/nova-cells.html

In the Kolla Ansible docs this is the 'dedicated cell controller topology' [1]. I could start by proposing a patch to replicate this bug in CI, and then we could take it from there. It looks like CI is testing a shared topology without the dedicated cell controllers and therefore doesn't pick this issue up.

A snippet from my inventory looks like this:

```
$ cat /etc/kolla/inventory/overcloud/group_vars/cell0001
nova_cell_name: cell0001
nova_cell_ironic_cell_name: cell0001
nova_cell_novncproxy_group: cell0001-vnc
nova_cell_conductor_group: cell0001-control
nova_cell_compute_group: cell0001-compute
nova_cell_compute_ironic_group: cell0001-control

[control:children]
top-level-controllers

[cell-control:children]
cell-controllers

# Top level top-level-controllers group.
[top-level-controllers]
os-ctrl01
os-ctrl02
os-ctrl03

[cell-controllers]
os-cellctrl01
os-cellctrl02
os-cellctrl03

[cell0001]
os-cellctrl01

[cell0001-control]
os-cellctrl01

[cell0001-compute]
os-compute0001
os-compute0002 ..

[cell0001-vnc]
os-cellctrl01
```

[1] https://docs.openstack.org/kolla-ansible/latest/reference/compute/nova-cells-guide.html#dedicated-cell-controller-topology