search domain not provided when using neutron internal dns

[Jason Hobbs]

my bundle has dns-domain and enable-ml2-dns set, but a search domain is not being provided to instances.

bundle: http://paste.ubuntu.com/p/jtRf4C9hZV/

No DNS Domain is reported by netplan or systemd:

http://paste.ubuntu.com/p/DY9MwkYGt8/

Resolution of hostnames for other instances only works if I use FQDN:
ubuntu@juju-d9ac39-kubernetes-9:~$ systemd-resolve juju-d9ac39-kubernetes-10
juju-d9ac39-kubernetes-10: resolve call failed: No appropriate name servers or networks for name found
ubuntu@juju-d9ac39-kubernetes-9:~$ systemd-resolve juju-d9ac39-kubernetes-10.openstack.customername.lan
juju-d9ac39-kubernetes-10.openstack.customername.lan: 172.16.0.23

-- Information acquired via protocol DNS in 3.4ms.
-- Data is authenticated: no

[Jason Hobbs (jason-hobbs)]

This is blocking our test of deploying k8s on top of FCB. I think I have a workaround in using dnsmasq-flags, so marking it high rather than critical.

[Jason Hobbs (jason-hobbs)]

sub'd to field high.

[James Page (james-page)]

I think this is bug 1774710; but please note there is a behaviour change in neutron which impacts rocky and queens which causes a different issue - neutron team are currently reviewing upstream but likely to revert a number of changes which includes the code that causes the issue you are seeing.

[Dmitrii Shcherbakov (dmitriis)]

It would be good to see if the --domain argument is being passed to dnsmasq processes spawned in qdhcp namespaces.

https://git.launchpad.net/~ubuntu-server-dev/ubuntu/+source/neutron/tree/neutron/agent/linux/dhcp.py?h=stable/queens#n422
        if self.conf.dns_domain:
            cmd.append('--domain=%s' % self.conf.dns_domain)

bug 1774710 seems very relevant but AFAIKS it is about passing dns_domain from a network object to dnsmasq rather than using a global config.

https://review.opendev.org/#/c/571546/7/neutron/agent/linux/dhcp.py
        self.dns_domain = self.network.get('dns_domain', self.conf.dns_domain)
# ...
        if self.dns_domain:
            cmd.append('--domain=%s' % self.dns_domain)

Jason's case is about the global config option (CONF/dns_domain) and he doesn't use the dns_domain network object attribute.

[James Page (james-page)]

This commit:

  https://opendev.org/openstack/neutron/commit/7fdd6adc7acf99e74fbe1c12606f8c867ae134ae

however I think that's only in our stein packages at the moment. But see my comments in #3

[Ryan Beisner (1chb1n)]

We believe this issue was resolved in: https://bugs.launchpad.net/bugs/1774710.

If the issue persists, please re-raise with updated logs, sanitized bundles, juju-crashdump, version details, etc. Thank you.