As initially mentioned in T72076#1035592, whenever OpenStack's dnsmasq is manually restarted, there is a short interval where various stuff complains because the sole DNS server isn't there. It would be nice to set up a second, caching/mirroring DNS server that could be added to /etc/resolv.conf (perhaps the order determined by the oddness of $ipaddress) and then would offer the opportunity to shut down one server for maintenance without an adrenalin rush.
This is probably something that other OpenStack users are interested as well, so a) perhaps someone has already developed something there and/or b) any local development should be advertised/coordinated upstream.