openresolv-discuss

Hi Petr

On 02/02/2021 13:09, Petr Menšík wrote:
> I am looking for simple way, how to check whether it is enabled.

...

> I think dhclient or any VPN implementation should not try to parse
> resolvconf.conf file. Is there good way I haven't spotted yet?
> How is it used by existing software?

From an applications perspective such as Network Manager, dhcpcd or OpenVPN, 
there is no such check other than "does /sbin/resolvconf exist?"

resolv="nameserver 1.2.3.4"
if [ -x /sbin/resolvconf ]; then
	echo "$resolv" | /sbin/resolvconf -a interface.foo
else
	echo "$resolv" > /etc/resolv.conf
fi

If resolvconf is present, it is assumed to be working.
It's been like so ever since the original Debian implementation and I've not 
seen a good reason to change this.

To "disable" openresolv you either remove it or set resolv_conf_passthrough=YES 
in resolvconf.conf which has the same effect as just writing directly to 
/etc/resolv.conf

Roy