Daemonize and Autostart under Debian and RHEL

Daemonizing and autostarting a process is still a pain in the ass, so here are two scripts which can be placed under /etc/init.d and if you are lucky everything will work.

Example is the punani backend, an universal package resolver and installer which is essentially a python webserver (now obsolete).

debian init-script

#! /bin/sh
# uses template from /etc/init.d/skeleton
### BEGIN INIT INFO
# Provides:          punani
# Required-Start:
# Required-Stop:
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: punani
# Description:       starts punani daemon
#
### END INIT INFO

PATH=/sbin:/usr/sbin:/bin:/usr/bin
NAME=punani
DESC="$NAME daemon"
DAEMON=/usr/bin/python
DAEMON_ARGS="/krebs/punani/index.py"
PIDFILE=/var/run/$NAME.pid
SCRIPTNAME=/etc/init.d/$NAME

[ -x "$DAEMON" ] || exit 0
[ -r /etc/default/$NAME ] && . /etc/default/$NAME
. /lib/init/vars.sh
. /lib/lsb/init-functions

do_start()
{
  #   0 if daemon has been started
  #   1 if daemon was already running
  #   2 if daemon could not be started
  start-stop-daemon -b --start --quiet --make-pidfile --pidfile $PIDFILE --exec $DAEMON --test > /dev/null \
          || return 1
  start-stop-daemon -b --start --quiet --make-pidfile --pidfile $PIDFILE --exec $DAEMON -- \
      $DAEMON_ARGS \
      || return 2
}

do_stop()
{
  #   0 if daemon has been stopped
  #   1 if daemon was already stopped
  #   2 if daemon could not be stopped
  start-stop-daemon --stop --retry=TERM/30/KILL/5 --pidfile $PIDFILE
  RETVAL="$?"
  [ "$RETVAL" = 2 ] && return 2
  rm -f $PIDFILE
  return "$RETVAL"
}

do_reload() {
  start-stop-daemon --stop --signal 1 --quiet --pidfile $PIDFILE
  return 0
}

case "$1" in
  start)
  [ "$VERBOSE" != no ] && log_daemon_msg "Starting $DESC" "$NAME"
  do_start
  case "$?" in
      0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
      2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
  esac
  ;;
  stop)
  [ "$VERBOSE" != no ] && log_daemon_msg "Stopping $DESC" "$NAME"
  do_stop
  case "$?" in
      0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
      2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
  esac
  ;;
  status)
       status_of_proc "$DAEMON" "$NAME" && exit 0 || exit $?
       ;;
  restart|force-reload)
  log_daemon_msg "Restarting $DESC" "$NAME"
  do_stop
  case "$?" in
    0|1)
      do_start
      case "$?" in
          0) log_end_msg 0 ;;
          1) log_end_msg 1 ;;
          *) log_end_msg 1 ;;
      esac
      ;;
    *)
      # Failed to stop
      log_end_msg 1
      ;;
  esac
  ;;
  *)
  echo "Usage: $SCRIPTNAME {start|stop|status|restart|force-reload}" >&2
  exit 3
  ;;
esac

:

register the script

update-rc.d punani defaults
service punani start

RHEL Init Script

#!/bin/bash
# `forked` (read stolen) from http://bitten.edgewall.org/wiki/BittenSlaveDaemonRedhat
#
# processname:       punani
# config:            /krebs/punani/config.json
# pidfile:           /var/run/punani.pid
# chkconfig: 2345 99 01
# description:       punani daemon

# Source function library.
. /etc/rc.d/init.d/functions

PATH=/sbin:/usr/sbin:/bin:/usr/bin
DESC="punani daemon"
NAME=punani
DAEMON=/usr/bin/python
DAEMON_ARGS="/krebs/punani/index.py"
DAEMON_USER=nobody
PIDFILE=/var/run/$NAME.pid

[ -x "$DAEMON" ] || exit 0

[ -r /etc/sysconfig/$NAME ] && . /etc/sysconfig/$NAME

start() {
        echo -n $"Starting $NAME: "
        daemon --user="$DAEMON_USER" --pidfile="$PIDFILE" "$DAEMON $DAEMON_ARGS &" # daemonize here
        RETVAL=$?
        pid=`ps -A | grep $NAME | cut -d" " -f2`
        pid=`echo $pid | cut -d" " -f2`
        if [ -n "$pid" ]; then
                echo $pid > "$PIDFILE"
        fi
        echo
        return $RETVAL
}
stop() {
        echo -n $"Stopping $NAME: "
        killproc -p "$PIDFILE" -d 10 "$DAEMON"
        RETVAL="$?"
        echo
        [ $RETVAL = 0 ] && rm -f "$PIDFILE"
        return "$RETVAL"
}

case "$1" in
  start)
        start
        ;;
  stop)
        stop
        ;;
  restart)
        stop
        start
        ;;
  *)
        echo "Usage: $NAME {start|stop|restart}" >&2
        exit 1
        ;;
esac

exit $RETVAL

register RHEL init-config

chkconfig punani on
service punani start

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