Comment 1 for bug 2036766

I tested the following successfully for this change:

Note: Fix for the following is required for upgrades: https://bugs.launchpad.net/charm-nova-cloud-controller/+bug/2037751

== upgrade ==

# deploy jammy-zed
openstack aggregate create ag-zed
openstack aggregate set --property availability_zone=az-zed ag-zed
openstack aggregate add host ag-zed $(openstack hypervisor list --column 'Hypervisor Hostname' --sort-column 'Hypervisor Hostname' --format value | grep 14)
openstack server create az-zed-on-zed --availability-zone az-zed --image cirros --flavor m1.tiny --nic net-id=private
openstack server show --column hypervisor_hostname --column availability_zone az-zed-on-zed

# upgrade to antelope
openstack aggregate create ag-antelope
openstack aggregate set --property availability_zone=az-antelope ag-antelope
openstack aggregate add host ag-antelope $(openstack hypervisor list --column 'Hypervisor Hostname' --sort-column 'Hypervisor Hostname' --format value | grep 15)
openstack server create az-antelope-on-antelope --availability-zone az-antelope --image cirros --flavor m1.tiny --nic net-id=private
openstack server create az-zed-on-antelope --availability-zone az-zed --image cirros --flavor m1.tiny --nic net-id=private
openstack server show --column hypervisor_hostname --column availability_zone az-antelope-on-antelope
openstack server show --column hypervisor_hostname --column availability_zone az-zed-on-antelope

# upgrade to bobcat
openstack aggregate create ag-bobcat
openstack aggregate set --property availability_zone=az-bobcat ag-bobcat
openstack aggregate add host ag-bobcat $(openstack hypervisor list --column 'Hypervisor Hostname' --sort-column 'Hypervisor Hostname' --format value | grep 16)
openstack server create az-bobcat-on-bobcat --availability-zone az-bobcat --image cirros --flavor m1.tiny --nic net-id=private
openstack server create az-antelope-on-bobcat --availability-zone az-antelope --image cirros --flavor m1.tiny --nic net-id=private
openstack server create az-zed-on-bobcat --availability-zone az-zed --image cirros --flavor m1.tiny --nic net-id=private
openstack server show --column hypervisor_hostname --column availability_zone az-bobcat-on-bobcat
openstack server show --column hypervisor_hostname --column availability_zone az-antelope-on-bobcat
openstack server show --column hypervisor_hostname --column availability_zone az-zed-on-bobcat

== new bobcat deploy ==

# deploy jammy-bobcat
openstack aggregate create ag-bobcat
openstack aggregate set --property availability_zone=az-bobcat ag-bobcat
openstack aggregate add host ag-bobcat $(openstack hypervisor list --column 'Hypervisor Hostname' --sort-column 'Hypervisor Hostname' --format value | grep 16)
openstack server create az-bobcat-on-bobcat --availability-zone az-bobcat --image cirros --flavor m1.tiny --nic net-id=private
openstack server show --column hypervisor_hostname --column availability_zone az-bobcat-on-bobcat