Hey Corey,
Great to see the charm coming along!
1) Since the interface is new I would love to see it based on the ``Endpoint`` class instead of the aging ``RelationBase`` class. Also the interface code needs unit tests. We have multiple examples of interface implementations with both in place you can get inspiration from [0].
Also consider having both a ``connected`` and ``available`` state, the available state could be set on the first relation-changed event. This increases the probability of your charm detecting a live charm in the other end of the relation, both states are also required to use the ``charms.openstack`` required relation gating code.
2) In the reactive handler you do a bespoke import of the charm class module just to activate the code, this is no longer necessary as there has been implemented a module that does automatic search and import of the class for you. Please use that instead. [1]
import charms_openstack.bus
import charms_openstack.charm as charm
charms_openstack.bus.discover()