Comment 2 for bug 1902264

Looking at the nova-cloud-controller charm, it looks like endpoint evaluation is only ever done in the relation-joined hook with keystone (https://github.com/openstack/charm-nova-cloud-controller/blob/25da3180b53abc9843cba37b12e08258de8644bf/hooks/nova_cc_hooks.py#L443). I haven't yet evaluated if that's the case across the rest of the charms but I suspect it is.

What that means is that whatever hostname(s) are configured when the initial relation to keystone is made is the hostname that will be put into the keystone catalog, and the config option will then never be re-evaluated in the context of the keystone relation. The charms consuming the keystone identity service relation need to be updated to ensure that they propagate URL updates to Keystone.