This switch testing of lists.openstack.org to Focal and we make a CGI
env var update to accomodate newer mailman.
Specifically newer mailman's CGI scripts filter env vars that it will
pass through. We were setting MAILMAN_SITE_DIR to vhost our mailman
installs with apache2, but that doesn't pass the filter and is removed.
HOST is passed through so we update our scripts, apache vhost configs,
exim, and init scripts to use the HOST env var instead.
We are using synchronize to copy the openstack mailman templates which
preserved the ownership and group and permissions of the source files on
bridge. This isn't a major problem but it is ugly so we fix it.
To fix it we set rsync_opts for synchronize to set a usermap and a
groupmap to map the bridge info to the data we want on the remote.
This converts our existing puppeted mailman configuration into a set of
ansible roles and a new playbook. We don't try to do anything new and
instead do our best to map from puppet to ansible as closely as
possible. This helps reduce churn and will help us find problems more
quickly if they happen.
Followups will further cleanup the puppetry.