#! /bin/bash
#=======================================================================
# chkconfig: 2345 86 16
# description: assigns ebs volume to a device and mounts the device and start mysql
#
# Procedure to add a normal startup script in CentOS
# - add two comments on the script:
#   chkconfig: 2345 86 16
#   description: mountebs etc..
#   NOTE:  chkconfig: 2345 (runlevels for the service), 86 (sequence when the service is started - ref: /etc/rc3.d), 16 (sequence when the service is stopped - /etc/rc0.d)
# - put script into /etc/init.d, chmod to 755
# - add to chkconfig: chkconfig --add mountebs
#
#=======================================================================
#  Here I added variables to make sure I have the correct paths
export EC2_HOME="/root/.ec2"
export PATH=$PATH:$EC2_HOME/bin
#  You need to the certificate and private key of your AWS account here
export EC2_PRIVATE_KEY=$EC2_HOME/pk-xxxx.pem
export EC2_CERT=$EC2_HOME/cert-xxxx.pem
export JAVA_HOME=/usr/java/default
export PATH=/root/.ec2/bin:$PATH

VOL="vol-xxxxxx"
DEV="/dev/sdh"
MOUNT_POINT="/ebs"
MAX_TRIES=60

prog=$(basename $0)
logger="logger -t $prog"
curl="curl --retry 3 --silent --show-error --fail"

# start/stop functions for OS

case "$1" in

start)
	ISMOUNTED=$(df | grep $DEV | wc -l)
	if [ $ISMOUNTED -eq 1 ]
	then
		/bin/echo "Volume already mounted. Exiting.."
		exit 1
	fi

	perl -MIO::Socket::INET -e '
	until(new IO::Socket::INET("169.254.169.254:80")){print"Waiting for network...\n";sleep 1}
	'  | $logger

	INSTANCE=$($curl http://169.254.169.254/latest/meta-data/instance-id)

	CTR=0
	/bin/echo "Mounting Elastic Block Store Volumes."
	/root/.ec2/bin/ec2-attach-volume $VOL -i $INSTANCE -d $DEV 2>/dev/null
	#/bin/echo "ec2-attach-volume $VOL -i $INSTANCE -d $DEV 2>/dev/null"
	
	while [ ! -e "$DEV" ]; do
		/bin/sleep 1
		CTR=`expr $CTR + 1`
		if [ $CTR -eq $MAX_TRIES ]
		then
			/bin/echo "WARNING: Cannot attach volume $VOL to $DEV -- Giving up after $MAX_TRIES attempts"
			exit 1
		fi
	done

	if [ ! -d $MOUNT_POINT ]; then
		mkdir $MOUNT_POINT
	fi

    # mount using ext3
    /bin/mount  -t xfs $DEV $MOUNT_POINT
    /etc/init.d/mysqld start
	;;

stop)
        /bin/echo "Unmounting Elastic Block Store Volumes."
        # only detach if umount is successful.
        /etc/init.d/mysqld stop
        /bin/umount $MOUNT_POINT && ec2-detach-volume $VOL  2>/dev/null
        rmdir $MOUNT_POINT

        ;;
restart)
        stop
        sleep 5
        start
        ;;
*)
        echo "Usage: $0 {start|stop|restart}"
        exit 1
        ;;
esac

exit 0