Otherwise I love HAProxy!
Edit: solved this one myself with a little research. Systemd also implements the /dev/log Unix domain socket (even with the silly syslog facility names, without needing syslog installed) - so:
log /dev/log local0 info
If the admin wants the logs in syslog, 2>&1 | logger or similar. If the admin wants to use multilog, s6-log, or journald, that's also easy.
(For the same reasons, daemons should not include daemonization routines but should run in the foreground. If I want it in the background, I'll arrange for my process supervisor to start it.)
If a daemon doesn't... daemonize into the background, it's no longer a daemon - just a process.
Silly loonix folks.
Please see the FreeBSD program daemon or the FreeBSD handbook section 3.8.
log /dev/stdout local0 info
[ALERT] 286/160528 (20831) : sendto logger #1 failed: Connection refused (errno=111)