a bash script for start or stop mongodb.

mongod.sh

#!/bin/bash

mongod=/usr/local/mongodb/bin/mongod
mongod_data=/Users/michito/work/mongodb_data
mongod_log=/Users/michito/work/mongodb_log/mongodb.log
prog=mongod.sh
RETVAL=0

stop() {
    grep_mongo=`ps aux | grep -v grep | grep "${mongod}"`
    if [ ${#grep_mongo} -gt 0 ]
    then
	echo "Stop MongoDB."
	PID=`ps x | grep -v grep | grep "${mongod}" | awk '{ print $1 }'`
	`kill -2 ${PID}`
	RETVAL=$?
    else
	echo "MongoDB is not running."
    fi
}
start() {
    grep_mongo=`ps aux | grep -v grep | grep "${mongod}"`
    if [ -n "${grep_mongo}" ]
    then
	echo "MongoDB is already running."
    else
	echo "Start MongoDB."
	`${mongod} --dbpath ${mongod_data} --logpath ${mongod_log} --fork --logappend`
	RETVAL=$?
    fi
}

case "$1" in
    start)
	start
	;;
    stop)
	stop
	;;
    restart)
	stop
	start
	;;
    *)
	echo $"Usage: $prog {start|stop|restart}"
	exit 1
esac

exit $RETVAL

look for this line
${mongod} --dbpath ${mongod_data} --logpath ${mongod_log} --fork --logappend
and modify for your prams ${} are used for variable substitution

If you could provide me resource to a tutorial for chef deployment of MongoDB replica sets

Thanks for the code. It is very useful. But on line 14 i would change ps x to ps ax. Because in my case it displayed nothing if I use ps x

Nice script, I also created an own script to start, stop, restart an mongodb-server under unix.
Maybe you could take a look: Mongodb_Start_Stop

One tipp for your grep command:
you used

grep -v grep

easier it would be if you use this:

grep_mongo=ps aux | grep [m]ongod
Then you get only one result with the right process of the mongod-server