bug#53225: shepherd freezes if wireguard is started with dns config enabled

[Nathan Dehnel <ncdehnel@gmail.com>]

>There should be lines like:

 > shepherd[1]: Service 'wireguard-XXX' has been started.

>Perhaps they’ve been moved to a different files due to log rotation?

>Without these, I cannot tell what happened.

I tried it again and found this
Jun  9 10:47:44 localhost vmunix: [    6.497581] wireguard: WireGuard
1.0.0 loaded. See www.wireguard.com for information.
Jun  9 10:47:44 localhost vmunix: [    6.497584] wireguard: Copyright
(C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights
Reserved.
Jun  9 10:47:44 localhost shepherd[1]: Failed to start wireguard-test
in the background.

On Thu, Jun 9, 2022 at 10:05 AM Ludovic Courtès <ludo@gnu.org> wrote:
>
> Hi Nathan,
>
> Nathan Dehnel <ncdehnel@gmail.com> skribis:
>
> >>Could you be more specific?  Specifically, could you share
> >>/var/log/messages for the parts related to Wireguard?
> >
> > root@guixtest ~# cat /var/log/messages | grep -i wireguardJun  8
> > 18:20:07 localhost vmunix: [    6.330271] wireguard: WireGuard 1.0.0
> > loaded. See www.wireguard.com for information.
> > Jun  8 18:20:07 localhost vmunix: [    6.330276] wireguard: Copyright
> > (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights
> > Reserved.
>
> There should be lines like:
>
>   shepherd[1]: Service 'wireguard-XXX' has been started.
>
> Perhaps they’ve been moved to a different files due to log rotation?
>
> Without these, I cannot tell what happened.
>
> >>However, the standard
> >>service constructors/destructors no longer block, and shepherd can serve
> >>multiple clients concurrently.
> >
> > I don't know, I guess wireguard uses "non-standard" constructors.
>
> Indeed, it invokes ‘wg-quick up’ and waits for completion.
>
> I suppose that command blocks until it has set up the VPN, right?
>
> If so, we’ll need to rewrite it differently.
>
> Thanks,
> Ludo’.