Best init script for running an application as a separate user - perl

Question

I have an application that runs in a user account (Plack-based) and want an init script.
It seems as easy as "sudo $user start_server ...". I just wrote an LSB script using start-stop-daemon and it is really clumsy and verbose. It doesn't feel like the right way.
After scouring for a bit and looking at a log of examples, I'm still not sure what the best way to do this is and there isn't a cohesive guide that I've found.
Right now I have it working with:
start-stop-daemon --background --quiet --start --pidfile $PIDFILE \
--make-pidfile --chuid $DAEMONUSER \
--exec $DAEMON -- $DAEMON_OPTS
With DAEMON and DAEMON_OPTS as:
DAEMON="/home/mediamogul/perl5/perlbrew/perls/current/bin/start_server"
DAEMON_OPTS="--port $PORT -- starman --workers $WORKERS /home/mediamogul/MediaMogul/script/mediamogul.psgi"
This then requires me to adjust how to detect running, because it's a perl script so perl is showing up as the command and not "start_server".
(I'm running this out of a perlbrew on that user account so it is completely separate from the system perl, that's why the paths are pointing to a perl in the user dir)
Is this really the best way to go about doing this? It seems very clunky to me, but I'm not an admin type.

Answer 1

You can use the --pid option to starman to have it write the PID when the app starts, if you use the same filename as you give start-stop-daemon then it will work nicly.
For example, from one of my init.d scripts:
SITENAME=mysite
PORT=5000
DIR=/websites/mysite
SCRIPT=bin/app.pl
USER=davidp
PIDFILE=/var/run/site-$SITENAME.pid
case "$1" in
start)
start-stop-daemon --start --chuid $USER --chdir $DIR \
--pidfile=$PIDFILE \
--exec /usr/local/bin/starman -- -p $PORT $SCRIPT -D --pid $PIDFILE
;;
stop)
start-stop-daemon --stop --pidfile $PIDFILE
;;
*)
echo "Usage: $SCRIPTNAME {start|stop}" >&2
exit 3
;;
esac
It's very close to what you are already doing, and I'll admit it is a little clumsy, granted, but it works - having Starman write the PID file means that start-stop-daemon can reliably start & stop it.