[bug#54986] [PATCH] gnu: mpd: Add support for socket activation.

[Liliana Marie Prikler <liliana.prikler@gmail.com>]

Am Mittwoch, dem 10.05.2023 um 17:14 +0200 schrieb Ludovic Courtès:
> Hi,
> 
> Liliana Marie Prikler <liliana.prikler@gmail.com> skribis:
> 
> > Am Mittwoch, dem 03.05.2023 um 15:27 +0200 schrieb Ludovic Courtès:
> > > It’s not just possible: several services in (gnu services …) and
> > > (gnu home services …) use endpoints for systemd or inetd-style
> > > startup.
> > True, but to my knowledge they don't yet allow the user to specify
> > those endpoints directly.  At the very least, they didn't when I
> > started this thread, which was shortly after shepherd itself gained
> > endpoints.  I'm happy to be proven wrong on this point.
> 
> They don’t let users specify the endpoints as such, but closely
> enough.  For instance, the ‘interface’ field of <bitlbee-
> configuration> is used to build it endpoint, and similarly for
> ‘openssh’ and ‘dicod’.
> 
> Overall, it seems to me we don’t need a first-class <endpoint> type
> in Guix System itself.
It's funny you would argue that, because imho openssh would actually be
a good candidate for supporting first-class endpoints:  Doing so would
allow the user to specify whether IPv4, IPv6 or both (default) should
be allowed for connections.  For other service that support sockets as
well as TCP/IP ports, the benefit would be even greater.

I understand that copypasting all the fields into Guix records is a bit
of a non-starter, but I don't think it's a good idea to simply give up.
I just need some pointers in which direction to continue.

Cheers