Upgrading Ubuntu from focal to jammy breaks on ovn-source

[Gustavo Sanchez]

========================= Versions
Juju 2.9.42
Ubuntu Focal
Openstack Yoga
OVN 22.03

========================= Description and logs
We were performing this procedure to upgrade a hypervisor from Ubuntu Focal to Jammy
https://docs.openstack.org/charm-guide/latest/admin/upgrades/series.html
https://docs.openstack.org/charm-guide/latest/admin/upgrades/series-openstack.html

Here the commands and outputs from the procedure
https://pastebin.ubuntu.com/p/hPds7GZ47M/

Running $ juju upgrade-series 28 complete --debug
Gets stuck
Also resulting in ovn-chassis in error state hook failed "post-series-upgrade"
"charmhelpers.fetch.SourceConfigError: Invalid Cloud Archive release specified: focal-ovn-22.03 on this Ubuntuversion (jammy)"

Additional information
juju config dgx-nova-compute -> https://paste.ubuntu.com/p/NMgks5b39m/
juju config ovn-chassis -> https://paste.ubuntu.com/p/jhmdqsYQzk/
juju config nova-compute -> https://paste.ubuntu.com/p/WDVx7StkvZ/

juju ssh 28 cat /var/log/juju/agents/machine-28.log -> https://pastebin.ubuntu.com/p/FYmTFFJTCf/
juju ssh 28 cat /var/log/juju/agents/unit-ovn-chassis-26.log -> https://pastebin.ubuntu.com/p/JVjTCBKs43/

========================= Others
The cloud is fully working from Openstack POV
However, this blocks finishing the execution of 'juju upgrade-series 28 complete'

Now, I was thinking on updating the value of ovn-chassis ovn-source to distro
However, I believe this would fix this machine that is on Jammy but then break all the others dgx-nova-compute that are still on Focal

The only "workaround" I am thinking is
1. Ignore that error message
2. Continue with the upgrade of the rest of the dgx-nova-compute machines from focal to jammy (without being able to wrap them with the complete command)
3. Once all of them are on jammy, update the value of ovn-chassis ovn-source to distro
4. Run the upgrade-series complete on each on the dgx-nova-compute machines

[Gustavo Sanchez (gustavosr98)]

Subscribing as 'field-high'
It might have a workaround

[Gustavo Sanchez (gustavosr98)]

We might want to add this to the docs on list of issues
https://docs.openstack.org/charm-guide/latest/project/issues-and-procedures.html