dnsmasq does not use -h, so /etc/hosts sends folks to loopback when they look up the machine it's running on

[Nick Moffitt]

 from dnsmasq(8):

      -h, --no-hosts
              Don't read the hostnames in /etc/hosts.

I reliably get bit by this during certain kinds of deployments, where my nova-network/dns host has an entry in /etc/hosts such as:

127.0.1.1 hostname.example.com hostname

I keep having to edit /etc/hosts on that machine to use a real IP, because juju gets really confused when it looks up certain openstack hostnames and gets sent to its own instance!

[Dan Smith (danms)]

This sounds like a JuJu problem to me :)

IMHO, /etc/hosts should not redirect $HOSTNAME to anything other than a routable external interface in a real environment with working DNS. Assuming your machine is not called "localhost" I think that this is a configuration issue.

[Dan Smith (danms)]

Oh, I misread what you were using JuJu for, thinking it was deploying your host. So, ignore the first line of my last comment. But, a config issue nonetheless, IMHO :)

[Nick Moffitt (nick-moffitt)]

Dan, this is the default behaviour for Ubuntu, which is the reference platform for Openstack.

Surely adding the -h flag would be easy and harmless, no?

[Nick Moffitt (nick-moffitt)]

This bug describes and interaction between Openstack and Ubuntu, for the most part.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Sean Dague (sdague)]

Under multihost we turn this on, so I think it's probably fine to also turn it on in the single host or single network node case.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/118613

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/118613
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=1e3d2fbcb13e01bee0a8f90bd2078b1f5063b4d5
Submitter: Jenkins
Branch: master

commit 1e3d2fbcb13e01bee0a8f90bd2078b1f5063b4d5
Author: Sean Dague <email address hidden>
Date: Wed Sep 3 07:49:51 2014 -0400

    always set --no-hosts for dnsmasq

    Many network modes in nova-network disable reading host entries from
    /etc/hosts. This includes running vish-ha (multihost), or if you ever
    set a dns server. However if you don't do these things we continue to
    use /etc/hosts.

    It's not clear that this does anything other than create
    inconsistency. There is a long standing bug that exists around this
    because the impacts include exposing localhost as a dns entry on the
    network.

    Change-Id: Ibccf0999bfd4b37f2d948af34640260f95c54572
    Closes-Bug: #1201873