Hi Jan,

> Does someone plan writing init script for Guix, so it will work on
> distributions using sysV init? There are still distributions not using
> systemd, for example Devuan and last time I checked, the install script
> doesn't support it.

I'm all for supporting it, but I can't remember all the idiocracies and I have no
machine to test it on.

That said, sysv init scripts are just shell scripts which support the arguments
"start", "status", "stop" and sometimes have an LSB header specifying where
to put the stuff (which runlevels are supposed to have it).

We would basically put the following file into /etc/init.d/guix-daemon
and make it executable:

#!/bin/bash -e
### BEGIN INIT INFO
# Provides:          guix-daemon
# Required-Start:    $remote_fs $syslog
# Required-Stop:     $remote_fs $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Guix build daemon
# Description:       Provides a daemon that does builds for Guix
### END INIT INFO

case "$1" in
start)
  daemonize -a -e /var/log/guix-daemon-stderr.log -o /var/log/guix-daemon-stdout.log -E GUIX_LOCPATH=/var/guix/profiles/per-user/root/guix-profile/lib/locale -E LC_ALL=en_US.utf8 -p /var/lock/guix-daemon.pid guix-daemon --build-users-group=guixbuild
  ;;
stop)
  pid="`cat /var/lock/guix-daemon.pid`"
  if [ ! -z "${pid}" ]
  then
    kill "${pid}"
    sleep 10
    kill -9 "${pid}"
  fi
  # TODO: Maybe remove /var/lock/guix-daemon.pid ?
  ;;
status)
  pid="`cat /var/lock/guix-daemon.pid`"
  if [ ! -z "${pid}" ]
  then
    if ps "${pid}" > /dev/null 2> /dev/null
    then
      echo "running"
    else
      echo "stale pid file"
    fi
  else
    echo "not running"
  fi
  ;;
*)
  echo "Usage: $0 (start|stop|status)"
  ;;
esac

I think in order to actually install the service one does this:

$ sudo update-rc.d guix-daemon defaults
$ sudo update-rc.d guix-daemon enable