Hi Wireguard folks--

over in https://bugs.debian.org/939904, Michael Biebl (in cc) pointed
out that on GNU/Linux systems supervised by systemd, if systemd-resolved
is running, it might make more sense for wg-quick to invoke resolvectl
directly with the DNS parameter instead of depending on resolvectl's
resolvconf-like symlink shim.

Jason, is that something that you'd be ok with, or is wg-quick wedded to
resolvconf, even if resolvectl is available and there is no resolvconf?
(and if you're ok with it, but if both exist, do you have a preference
for which one should be used?)

Is anyone interested in hacking on src/tools/wg-quick/linux.bash to
enable this?  I think the command should be pretty simple -- the main
things to get right are detection of subsystem availability and conflict
resolution.

I guess my preference would be something like:

 * if resolvectl exists, try to use it.  if it succeeds, done.  (it
   might fail if systemd-resolved is not running, for example)

 * otherwise, try using resolvconf.

but of course this is Jason's call to make.

       --dkg