[Dnsmasq-discuss] Polling of hosts file

Franco Broi franco.broi at iongeo.com
Wed Mar 19 09:24:00 UTC 2014

I hear what you say but for me it would be very convenient, I have
several dnsmasq servers all reading the same shared hosts file.

My currently solution is to run a script from cron that detects a change
and sends HUP to dnsmasq.

You could have a few simple safeguards, like delaying the update if the
number of hosts has reduced drastically etc.. 

On Wed, 2014-03-19 at 09:07 +0000, Simon Kelley wrote: 
> On 19/03/14 04:04, Franco Broi wrote:
> > Hi
> > 
> > Just wondering why dnsmasq doesn't poll the hosts file for changes like
> > it does for resolv.conf?
> > 
> Polling files is dangerous. You can get race conditions where the update
> time changes but the file is still in the process of being written.
> Polling resolv.conf is necessary because there are lots of things which
> just write it and expect the changes to be picked up (because that's
> what the resolver library does.) That's not true for /etc/hosts, so it's
> better to mandate the update-then-signal model.
> Cheers,
> Simon.
> _______________________________________________
> Dnsmasq-discuss mailing list
> Dnsmasq-discuss at lists.thekelleys.org.uk
> http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss

More information about the Dnsmasq-discuss mailing list