Re: [PATCH] Use SIGKILL to be able to immediately start a new dnsmasq afterwards

[Howard Chu <hyc symas com>]

> Date: Sat, 05 May 2012 15:03:42 +0200
> From: Michael Stapelberg <michael+nm stapelberg de>

> Hey,
>
> attached you will find a patch which fixes a problem with dnsmasq for me. Quote
> from the commit message:
>
> Use SIGKILL to be able to immediately start a new dnsmasq afterwards
>
> This fixes the problem that when updating the DNS configuration, dnsmasq would
> fail to start up with a message like this:
>
> May  5 14:43:47 x200 dnsmasq[5172]: failed to create listening socket for
> 127.0.0.1: Address already in use
> May  5 14:43:47 x200 dnsmasq[5172]: FAILED to start up
>
> The reason for that is that the other dnsmasq instance is still running ? it
> doesn?t react to SIGTERM at all, so it was still running and NM was waiting for
> the 2-second timeout to happen.
>
> You can easily verify that dnsmasq doesn?t react to SIGTERM:

Killing and restarting dnsmasq each time you need to make a change has all the 
elegance of a kick in the groin. Problems like this wouldn't exist if you used 
DBUS to manage dnsmasq.

If my previous patch is a problem because you don't want to rely on an 
existing system-provided dnsmasq instance, the obvious solution is to add an 
option to dnsmasq to have instance-specific DBUS services, not to start/stop 
your private instance repeatedly every time the network topology changes.

--
  -- Howard Chu
  CTO, Symas Corp.           http://www.symas.com
  Director, Highland Sun     http://highlandsun.com/hyc/
  Chief Architect, OpenLDAP  http://www.openldap.org/project/