Comment 6 for bug 1538812

The problem pops up when using the "manual" provider. I've just spun up a simplified test environment to confirm the problem; the exact Juju config is here if it helps: https://www.hastexo.com/resources/hints-and-kinks/ubuntu-openstack-juju-4-nodes/

After running that setup, cinder-volume and neutron-gateway are broken:

$ juju stat neutron-gateway --format=oneline

- neutron-gateway/0: charlie.example.com (error)

$ juju stat cinder-volume --format=oneline

- cinder-volume/0: daisy.example.com (error)

$ juju debug-log --replay | grep NXDOMAIN
unit-neutron-gateway-0[22632]: 2016-01-28 18:50:56 INFO unit.neutron-gateway/0.install logger.go:40 raise NXDOMAIN
unit-neutron-gateway-0[22632]: 2016-01-28 18:50:56 INFO unit.neutron-gateway/0.install logger.go:40 dns.resolver.NXDOMAIN
unit-cinder-volume-0[22570]: 2016-01-28 18:52:39 INFO unit.cinder-volume/0.install logger.go:40 raise NXDOMAIN
unit-cinder-volume-0[22570]: 2016-01-28 18:52:39 INFO unit.cinder-volume/0.install logger.go:40 dns.resolver.NXDOMAIN

By the way: why exactly is this just an INFO message when it's an unhandled exception that, according to the comment, "kills the hook"?

All nodes have an /etc/hosts file that makes them mutually resolvable by gethostbyname(), but they use 8.8.8.8 and 8.8.4.4 for their DNS servers, which means they obviously can't resolve each other's host names via DNS.