Comment 30 for bug 1671422

David Ames (thedac) wrote :

It would seem the upgrade to Ocata changes the auth_username to cinder in the database and leaves secret_uuid Null. This may be because cinder did not already have a rbd_secret_uuid set during the upgrade. Adding cinder-ceph to the equation adds this but does not on its own update the nova DB. (more testing needed)

The patch [0] and the package updates [1] will be required for the fall back to nova's rbd_username and rbd_secret_uuid for existing volume backed instances.

The path forward:

When [1] packages are available update packages on nodes. This will handle all existing instances.
Add cinder ceph to the model. New instances will use the cinder-ceph credentials.

Needs further testing:
Remove relation between cinder and ceph-mon
Test non nova cinder volumes after the topology change
To future proof against the fallback being removed:
  Either update the DB similar to [2]
  Or create an action similar to [3] that does this for us.

[0] https://review.openstack.org/#/c/626897/
[1] https://bugs.launchpad.net/nova/+bug/1809454
[2] https://pastebin.canonical.com/p/4ZdVnzpSp8/
[3] https://github.com/openstack/charm-cinder/blob/stable/18.11/actions.yaml#L14