Comment 0 for bug 1828293

The upgrade process from Queens to Rocky fails due to a failure to override a policy file:
https://paste.ubuntu.com/p/tH4qrvP7mS/

The issue causes an upgrade action to exit prematurely which leaves the dashboard in a broken state as the keystone v3 policy json file is not rendered.

KEYSTONEV3_POLICY = ('/usr/share/openstack-dashboard/openstack_dashboard/conf/'
                     'keystonev3_policy.json')

This is reproducible without charms by simply doing the following:

lxc launch ubuntu:bionic neutrontest
Creating neutrontest
Starting neutrontest

lxc exec neutrontest bash
root@neutrontest:~# apt update
root@neutrontest:~# apt install python-neutron-fwaas-dashboard
# ... https://paste.ubuntu.com/p/RMKbNH5DbB/

root@neutrontest:~# add-apt-repository cloud-archive:rocky
root@neutrontest:~# python3-neutron-fwaas-dashboard
https://paste.ubuntu.com/p/4Fq9MvpP9p/

Unpacking python3-neutron-fwaas-dashboard (1.5.0-0ubuntu3~cloud0) ...
dpkg: error processing archive /tmp/apt-dpkg-install-R0ZsZb/111-python3-neutron-fwaas-dashboard_1.5.0-0ubuntu3~cloud0_all.deb (--unpack):
 trying to overwrite '/etc/openstack-dashboard/neutron-fwaas-policy.json', which is also in package python-neutron-fwaas-dashboard 1.3.0-0ubuntu1.1

The same issue in an output of execution of a charm action (19.04):

2019-05-08 14:38:12 DEBUG openstack-upgrade /tmp/apt-dpkg-install-3M5oD6/099-python3-neutron-fwaas-dashboard_1.5.0-0ubuntu3~cloud0_all.deb
2019-05-08 14:38:14 DEBUG openstack-upgrade E: Sub-process /usr/bin/dpkg returned an error code (1)
2019-05-08 14:38:14 INFO juju-log Couldn't acquire DPKG lock. Will retry in 10 seconds
2019-05-08 14:38:24 DEBUG openstack-upgrade Reading package lists...
2019-05-08 14:38:24 DEBUG openstack-upgrade Building dependency tree...
2019-05-08 14:38:24 DEBUG openstack-upgrade Reading state information...
2019-05-08 14:38:24 DEBUG openstack-upgrade libapache2-mod-wsgi-py3 is already the newest version (4.5.17-1).
2019-05-08 14:38:24 DEBUG openstack-upgrade python3-pymysql is already the newest version (0.8.0-1).
2019-05-08 14:38:24 DEBUG openstack-upgrade haproxy is already the newest version (1.8.8-1ubuntu0.4).
2019-05-08 14:38:24 DEBUG openstack-upgrade memcached is already the newest version (1.5.6-0ubuntu1.1).
2019-05-08 14:38:24 DEBUG openstack-upgrade python3-memcache is already the newest version (1.57-2ubuntu0.18.04.1).
2019-05-08 14:38:24 DEBUG openstack-upgrade openstack-dashboard is already the newest version (3:14.0.2-0ubuntu2~cloud0).
2019-05-08 14:38:24 DEBUG openstack-upgrade openstack-dashboard-ubuntu-theme is already the newest version (3:14.0.2-0ubuntu2~cloud0).
2019-05-08 14:38:24 DEBUG openstack-upgrade python3-designate-dashboard is already the newest version (7.0.0-0ubuntu1~cloud0).
2019-05-08 14:38:24 DEBUG openstack-upgrade python3-django-horizon is already the newest version (3:14.0.2-0ubuntu2~cloud0).
2019-05-08 14:38:24 DEBUG openstack-upgrade python3-heat-dashboard is already the newest version (1.4.0-0ubuntu1~cloud0).
2019-05-08 14:38:24 DEBUG openstack-upgrade python3-keystoneclient is already the newest version (1:3.17.0-0ubuntu1~cloud0).
2019-05-08 14:38:24 DEBUG openstack-upgrade python3-neutron-lbaas-dashboard is already the newest version (5.0.0-0ubuntu1~cloud0).
2019-05-08 14:38:24 DEBUG openstack-upgrade python3-novaclient is already the newest version (2:11.0.0-0ubuntu1~cloud0).
2019-05-08 14:38:24 DEBUG openstack-upgrade The following packages were automatically installed and are no longer required:
2019-05-08 14:38:24 DEBUG openstack-upgrade python-pika-pool python-positional python-retrying
2019-05-08 14:38:24 DEBUG openstack-upgrade Use 'apt autoremove' to remove them.
2019-05-08 14:38:24 DEBUG openstack-upgrade The following NEW packages will be installed:
2019-05-08 14:38:24 DEBUG openstack-upgrade python3-neutron-fwaas-dashboard
2019-05-08 14:38:25 DEBUG openstack-upgrade 0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
2019-05-08 14:38:25 DEBUG openstack-upgrade 109 not fully installed or removed.
2019-05-08 14:38:25 DEBUG openstack-upgrade Need to get 0 B/55.6 kB of archives.
2019-05-08 14:38:25 DEBUG openstack-upgrade After this operation, 630 kB of additional disk space will be used.
(Reading database ... 81446 files and directories currently installed.)
2019-05-08 14:38:25 DEBUG openstack-upgrade Preparing to unpack .../python3-neutron-fwaas-dashboard_1.5.0-0ubuntu3~cloud0_all.deb ...
2019-05-08 14:38:25 DEBUG openstack-upgrade Unpacking python3-neutron-fwaas-dashboard (1.5.0-0ubuntu3~cloud0) ...
2019-05-08 14:38:25 DEBUG openstack-upgrade dpkg: error processing archive /var/cache/apt/archives/python3-neutron-fwaas-dashboard_1.5.0-0ubuntu3~cloud0_all.deb (--unpack):
2019-05-08 14:38:25 DEBUG openstack-upgrade trying to overwrite '/etc/openstack-dashboard/neutron-fwaas-policy.json', which is also in package python-neutron-fwaas-dashboard 1.3.0-0ubuntu1.1
2019-05-08 14:38:25 DEBUG openstack-upgrade Errors were encountered while processing:
2019-05-08 14:38:25 DEBUG openstack-upgrade /var/cache/apt/archives/python3-neutron-fwaas-dashboard_1.5.0-0ubuntu3~cloud0_all.deb
2019-05-08 14:38:27 DEBUG openstack-upgrade E: Sub-process /usr/bin/dpkg returned an error code (1)
2019-05-08 14:38:27 INFO juju-log Couldn't acquire DPKG lock. Will retry in 10 seconds