Comment 2 for bug 1501189

I'm sympathetic to aim, but this solution is rather fragile, there are
plenty of ways to get dnsmasq to read configuration from places other
than /etc/dnsmasq.conf and /etc/dnsmasq.d/*, for instance adding

conf-file=/path/to/more/configuration

to the existing config files.

It's also possible to override things in /etc/default/dnsmasq.

A better solution might be to extend the IGNORE_RESOLVCONF setting in
/etc/default/dnsmasq so that it inhibits adding 127.0.0.1 to resolvconf,
as well as stopping dnsmasq from using the resolvconf output as upstream.

Simon.

On 30/09/15 07:38, Alkis Georgopoulos wrote:
> Public bug reported:
>
> The following function is defined in /etc/init.d/dnsmasq:
>
> start_resolvconf()
> {
> # If interface "lo" is explicitly disabled in /etc/default/dnsmasq
> # Then dnsmasq won't be providing local DNS, so don't add it to
> # the resolvconf server set.
> for interface in $DNSMASQ_EXCEPT
> do
> [ $interface = lo ] && return
> done
>
> if [ -x /sbin/resolvconf ] ; then
> echo "nameserver 127.0.0.1" | /sbin/resolvconf -a lo.$NAME
> fi
> return 0
> }
>
> When someone puts port=0 in dnsmasq.conf, because e.g. he wants to use it only as a (proxy)DHCP/TFTP server,
> 127.0.0.1 is added to resolvconf, and DNS is broken because nothing listens there.
>
> One workaround is to put DNSMASQ_EXCEPT=lo in /etc/default/dnsmasq.
> But that doesn't make much sense, we don't want to exclude some interface, we're not running a DNS server at all.
>
> So it would be nice if dnsmasq checked if port=0 is defined in its
> configuration, and didn't add 127.0.0.1 to resolvconf then.
>
> Sample implementation code, to be inserted before `if [ -x /sbin/resolvconf ]`:
> grep -qr port=0 /etc/dnsmasq.d/ /etc/dnsmasq.conf && return
>
> ** Affects: dnsmasq (Ubuntu)
> Importance: Undecided
> Status: New
>
>
> ** Tags: patch
>