Deamons, Pids and Wrappers

[Andreas Theissen]

... and final reply on Vol 98, Issue 18 (wrong quotes)

first of all thank you again for that quick answer to my silly question. I must have been too tired that that day, so I simply  copied these wrong quotes from anywhere . As you wrote, of course monit is plain sailing now and gracefully monitors anything via web interface , which has a pid-file in /var/run, for example.

Besides that I've also configered a very basic iptables firewall script, which is also runs fine, and which can be started and stopped either in  /etc/init.d/ or runlevel based  (I achieved the latter by using update-rc.d). The script looks like:

#! /bin/bash

### BEGIN INIT INFO
# Provides:          myFirewall
# Required-Start:    $remote_fs $syslog
# Required-Stop:     $remote_fs $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Start myFirewall or so at boot time
# Description:       Enable service provided by myFirewall.
### END INIT INFO

ECHO="/bin/echo"
SYSCTL="/sbin/sysctl"
IPTABLES="/sbin/iptables"

# Firewall Rules and so on...

esac
exit 0

Though the script runs perfectly, monit can't monitor the deamon, as it doesn't generate a pidfile itself in /var/run or anywhwere else.

In the Monit-FAQ (http://mmonit.com/wiki/Monit/FAQ ) I found some advice to configurate a wrapper, which generates the pidfile for a specific Applications (Java&tm; in that case).

#!/bin/bash
export JAVA_HOME=/usr/local/java/
CLASSPATH=ajarfile.jar:.

case $1 in
start)
echo $$ > /var/run/xyz.pid;
exec 2>&1 java -cp ${CLASSPATH} org.something.with.main 1>/tmp/xyz.out
;;
stop)
kill `cat /var/run/xyz.pid` ;;
*)
echo "usage: xyz {start|stop}" ;;
esac
exit 0

I simply wonder how to make this work for my little idiot's firewall deamon somehow - especially concerning the line with the ugly 'exec' in front.
Though it is a very beginner's problem again, maybe more generalized examples in your FAQ could also be a good idea to prevent fools like me from wasting your time :)

best regards

Andreas