#!/bin/bash
set +u
shopt -s xpg_echo
shopt -s expand_aliases
unset PATH JAVA_HOME LD_LIBRARY_PATH
function abort {
   echo "aborting: $@" 1>&2
   exit 1
}
function default {
   export INSTANCE_NAME="mkebsboot"
export INSTANCE_HOME="/tmp"
export LOG_DIR="/tmp/logs"
   return 0
}
function mkebsboot {
   export IMAGE_DIR="/mnt/tmp"
export EBS_DEVICE="/dev/sdh"
export EBS_MOUNT_POINT="/mnt/ebs"
   return 0
}
function findPid {
   unset FOUND_PID;
   [ $# -eq 1 ] || {
      abort "findPid requires a parameter of pattern to match"
      return 1
   }
   local PATTERN="$1"; shift
   local _FOUND=`ps auxwww|grep "$PATTERN"|grep -v " $0"|grep -v grep|awk '{print $2}'`
   [ -n "$_FOUND" ] && {
      export FOUND_PID=$_FOUND
      return 0
   } || {
      return 1
   }
}
function forget {
   unset FOUND_PID;
   [ $# -eq 3 ] || {
      abort "forget requires parameters INSTANCE_NAME SCRIPT LOG_DIR"
      return 1
   }
   local INSTANCE_NAME="$1"; shift
   local SCRIPT="$1"; shift
   local LOG_DIR="$1"; shift
   mkdir -p $LOG_DIR
   findPid $INSTANCE_NAME
   [ -n "$FOUND_PID" ] && {
      echo $INSTANCE_NAME already running pid [$FOUND_PID]
   } || {
      nohup $SCRIPT >$LOG_DIR/stdout.log 2>$LOG_DIR/stderr.log &
      sleep 1
      findPid $INSTANCE_NAME
      [ -n "$FOUND_PID" ] || abort "$INSTANCE_NAME did not start"
   }
   return 0
}
export PATH=/usr/ucb/bin:/bin:/sbin:/usr/bin:/usr/sbin
case $1 in
init)
   default || exit 1
   mkebsboot || exit 1
   mkdir -p $INSTANCE_HOME
   
   # create runscript header
   cat > $INSTANCE_HOME/mkebsboot.sh <<END_OF_SCRIPT
#!/bin/bash
set +u
shopt -s xpg_echo
shopt -s expand_aliases
PROMPT_COMMAND='echo -ne "\033]0;mkebsboot\007"'
export PATH=/usr/ucb/bin:/bin:/sbin:/usr/bin:/usr/sbin
export INSTANCE_NAME='mkebsboot'
export IMAGE_DIR='$IMAGE_DIR'
export EBS_DEVICE='$EBS_DEVICE'
export EBS_MOUNT_POINT='$EBS_MOUNT_POINT'
export INSTANCE_NAME='$INSTANCE_NAME'
export INSTANCE_HOME='$INSTANCE_HOME'
export LOG_DIR='$LOG_DIR'
END_OF_SCRIPT
   
   # add desired commands from the user
   cat >> $INSTANCE_HOME/mkebsboot.sh <<'END_OF_SCRIPT'
cd $INSTANCE_HOME
echo creating a filesystem and mounting the ebs volume
mkdir -p $IMAGE_DIR $EBS_MOUNT_POINT
rm -rf $IMAGE_DIR/*
yes| mkfs -t ext3 $EBS_DEVICE 2>&-
mount $EBS_DEVICE $EBS_MOUNT_POINT
echo making a local working copy of the boot disk
rsync -ax --exclude /ubuntu/.bash_history --exclude /home/*/.bash_history --exclude /etc/ssh/ssh_host_* --exclude /etc/ssh/moduli --exclude /etc/udev/rules.d/*persistent-net.rules --exclude /var/lib/ec2/* --exclude=/mnt/* --exclude=/proc/* --exclude=/tmp/* --exclude=/dev/log / $IMAGE_DIR
echo preparing the local working copy
touch $IMAGE_DIR/etc/init.d/ec2-init-user-data
echo copying the local working copy to the ebs mount
cd $IMAGE_DIR
tar -cSf - * | tar xf - -C $EBS_MOUNT_POINT
echo size of ebs
du -sk $EBS_MOUNT_POINT
echo size of source
du -sk $IMAGE_DIR
rm -rf $IMAGE_DIR/*
umount $EBS_MOUNT_POINT
echo ----COMPLETE----
END_OF_SCRIPT
   
   # add runscript footer
   cat >> $INSTANCE_HOME/mkebsboot.sh <<'END_OF_SCRIPT'
exit 0
END_OF_SCRIPT
   
   chmod u+x $INSTANCE_HOME/mkebsboot.sh
   ;;
status)
   default || exit 1
   findPid $INSTANCE_NAME || exit 1
   echo [$FOUND_PID]
   ;;
stop)
   default || exit 1
   findPid $INSTANCE_NAME || exit 1
   [ -n "$FOUND_PID" ]  && {
      echo stopping $FOUND_PID
      kill -9 $FOUND_PID
   }
   ;;
start)
   default || exit 1
   forget $INSTANCE_NAME $INSTANCE_HOME/$INSTANCE_NAME.sh $LOG_DIR || exit 1
   ;;
tail)
   default || exit 1
   tail $LOG_DIR/stdout.log
   ;;
tailerr)
   default || exit 1
   tail $LOG_DIR/stderr.log
   ;;
run)
   default || exit 1
   $INSTANCE_HOME/$INSTANCE_NAME.sh
   ;;
esac
exit 0