On Sat, 14 Nov 2020 at 19:35, Sam Varshavchik <mrsam@courier-mta.com> wrote:
Anthony F McInerney writes:

>        Note that the selected mode of operation for this file is detected 
> fully automatically, depending on whether /etc/resolv.conf is a symlink to
>        /run/systemd/resolve/resolv.conf or lists 127.0.0.53 as DNS server.

Again: why does anything have to be "detected fully automatically"?

We've had a mechanism for controlling symlinks for an eternity: 
alternatives.

I cannot see any valid technical argument against having /etc/resolv.conf 
managed by alternatives. If systemd-resolved wishes to have the highest 
alternatives priority, and thus ends up being the resolver by default, 
that's fine.

Does anyone have an argument /against/ having /etc/resolv.conf managed via 
alternatives? What can't you do with alternatives that you can with the 
current ham-fisted approach, where someone has to go out of their way to 
figure out how to switch to network manager-provided resolv.conf?



Can someone explain why systemd-resolved needs to symlink /etc/resolv.conf to 4(or more) different places, instead of just having those 'detected things' as options in /etc/systemd/resolved.conf ?

Also spotted this on the Arch Wiki

"systemd-resolved will work out of the box with a network manager using /etc/resolv.conf. No particular configuration is required since systemd-resolved will be detected by following the /etc/resolv.conf symlink. This is going to be the case with systemd-networkd or NetworkManager."