Upgrading designate from pike to queens does not provide charm check for "nameserver" setting

[Drew Freiberger]

designate charm version 18.05 I noticed that on openstack deployments with the designate service that after upgrading openstack-origin from cloud:xenial-pike to cloud:xenial-queens, that the units are in "unit is ready" status and work fine. However, when I deploy new units of this service, they exhibit a blocking status with the message "nameservers must be set".

It appears that the config.yaml notes that the "nameservers" setting is required for queens, but the config-change for openstack-origin to a queens release does not trigger the custom_assess_status_check which checks for 'nameserver' to be set, but installing new units does.

Mock actions to reproduce:

juju deploy designate with config: openstack-origin=cloud:xenial-pike
*add required relations with rmq/nova/designate-bind*
juju config designate openstack-origin=cloud:xenial-queens
*perform juju action openstack-upgrade on units*
* Note lack of blocked status *

juju add-unit designate
* note blocked status of new unit with running status of original unit *

[Chris MacNaughton (chris.macnaughton)]

I just followed these directions precisely and I cannot reproduce this. See attached juju status

[Launchpad Janitor (janitor)]

[Expired for OpenStack Designate Charm because there has been no activity for 60 days.]