start-stop-daemon not working as expected, no pid file was written

Question

I'm trying to control a python based program (which doesn't detach itself from console)

#!/bin/bash

user=nobody
pid=/var/run/xx.pid
name=xx
prog=/xx.py

case $1 in
    start)
        /sbin/start-stop-daemon --start -b --oknodo --user "$user" --name "$name" --pidfile "$pid" --startas "$prog" --chuid nobody -- --daemon
        ;;
    stop)
        /sbin/start-stop-daemon --stop --oknodo --user "$user" --name "$name" --pidfile "$pid" --retry=TERM/5/KILL/1
        ;;
    restart)
        ;;
    *)
        ;;
esac

The start part works fine. I can see the script up and running, but the stop part doesn't. It simply says No xx found running; none killed.

So I guess there's something wrong with the start part?

Answer 1

start-stop-daemon --start --pidfile "$pid" doesn't write to the pid file unless --make-pidfile (-m) is specified. Without --make-pidfile it is up to the program being launched to create it. Also for --make-pidfile to work, the process being launched can't daemonize itself (via a fork), as then start-stop-daemon won't know what PID it should put in the file.

The only thing --pidfile "$pid" does in your usage scenario is that it will result in start-stop-daemon not starting the program if it is already running.

---

If process still is not stopping, all the criteria passed to start-stop-daemon --stop must match. Meaning $pid has to be a running process, the UID of the process has to match $user, and the process name (arg0) has to match $name.
You can determine the value of arg0 by doing ps h -p $pid -o comm