neutron-ovn-metadata-agent down after migration from ovs

[Liam Young]

When running a migration from ovs to ovn the neutron-ovn-metadata-agent is not installed.

At the moment I think the cause is (I still need to verify this):

ovn-chassis is deployed paused *1 . charm.ovn-chassis.enable-openstack is not set if the charm is paused *2. If charm.ovn-chassis.enable-openstack is not set then neutron-ovn-metadata-agent is not added to the list of packages to install *3 and hence the service is not running after the upgrade.

*1 https://opendev.org/openstack/charm-neutron-gateway/src/branch/master/tests/bundles/focal-ussuri.yaml#L157
*2 https://github.com/openstack-charmers/charm-layer-ovn/blob/master/reactive/ovn_chassis_charm_handlers.py#L65
*3 https://github.com/openstack-charmers/charm-layer-ovn/blob/master/lib/charms/ovn_charm.py#L679

Seen on OSCI on focal-ussuri:

https://review.opendev.org/c/openstack/charm-neutron-gateway/+/770412
https://openstack-ci-reports.ubuntu.com/artifacts/test_charm_pipeline_func_full/openstack/charm-neutron-gateway/770412/1/7758/index.html

All ovn-chassis instances are blocked with "Services not running that should be: neutron-ovn-metadata-agent"

[Liam Young (gnuoy)]

A subsequent (non-update-status) hook execution will fix things.

[Aurelien Lourot (aurelien-lourot)]

Also visible here on groovy-victoria:
https://review.opendev.org/c/openstack/charm-neutron-gateway/+/761575
https://openstack-ci-reports.ubuntu.com/artifacts/test_charm_pipeline_func_full/openstack/charm-neutron-gateway/761575/2/7704/index.html

[Aurelien Lourot (aurelien-lourot)]

https://github.com/openstack-charmers/charm-layer-ovn/pull/33

[Aurelien Lourot (aurelien-lourot)]

Landed, so this fix will be in the next revision of https://jaas.ai/u/openstack-charmers-next/ovn-chassis , i.e. revision 49

[Aurelien Lourot (aurelien-lourot)]

Regarding my last comment, a new revision will be published as soon as this review lands:
https://review.opendev.org/c/x/charm-ovn-chassis/+/771874