New unit stuck on 'shared-db' incomplete

[Jake Nabasny]

== Summary ==
After migrating a magnum unit in a LXD container to new hardware, it became stuck in 'shared-db' incomplete status. Attempting to `juju add-unit` additional units resulted in the same error. Magnum is currently related to the mysql db through the mysql-router subordinate charm, so we attempted to refresh the relation by removing and readding it:

juju remove-relation magnum-mysql-router:shared-db magnum:shared-db
juju relate magnum-mysql-router:shared-db magnum:shared-db

This step led to all existing units now showing the "'shared-db' incomplete" error.

== Workaround ==
We were able to resolve the error by relating magnum directly to the mysql db:

juju relate mysql-innodb-cluster:shared-db magnum:shared-db

However, this shouldn't be necessary since the mysql-router exists on the magnum units. There seems to be a bug in magnum's integration with the mysql-router.

== Versions ==
Ubuntu 20.04 and 22.04
OpenStack Yoga
magnum 14.1.1 rev 42
magnum-hacluster 2.0.3 rev 131
magnum-mysql-router 8.0.36 rev 137

[Alex Kavanagh (ajkavanagh)]

Unfortunately, there's not enough information in the bug to diagnose the error. Please could you add the juju logs from the magnum unit, and the associated mysql-router, and "juju show-unit" for both the magnum unit, and the mysql-router. the juju status for the model would also be useful.

Also, when you say "migrate" do you mean "add-unit" "remove-unit" or something else?

[Jake Nabasny (slapcat)]

Hi Alex - By migrate I meant using "lxc mv" to move the container from one host to another. I don't currently have my lab up to provide the other outputs, but I will try to get them for you.