shutdown_email.sh

#!/bin/sh
### BEGIN INIT INFO
# Provides: SystemEmail
# Required-Start: $remote_fs $syslog
# Required-Stop: $remote_fs $syslog
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: Send email
# Description: Sends an email at system start and shutdown
### END INIT INFO

EMAIL="example@example.com"
RESTARTSUBJECT="["`hostname`"] – System Startup"
SHUTDOWNSUBJECT="["`hostname`"] – System Shutdown"
RESTARTBODY="This is an automated message to notify you that "`hostname`" started successfully.

Start up Date and Time: "`date`
SHUTDOWNBODY="This is an automated message to notify you that "`hostname`" is shutting down.
Shutdown Date and Time: "`date`
LOCKFILE=/var/lock/SystemEmail
RETVAL=0

# Source function library.
. /lib/lsb/init-functions

stop()
{
   echo -n $"Sending Shutdown Email: "
   echo "${SHUTDOWNBODY}" | mail -s "${SHUTDOWNSUBJECT}" ${EMAIL}
   sleep 4
   RETVAL=$?

   sleep 4
   if [ ${RETVAL} -eq 0 ]; then
      rm -f ${LOCKFILE}
      sleep 4
      success
   else
      failure
   fi
   echo
   return ${RETVAL}
}

start()
{
   echo -n $"Sending Startup Email: "
   echo "${RESTARTBODY}" | mail -s "${RESTARTSUBJECT}" ${EMAIL}
   RETVAL=$?

   if [ ${RETVAL} -eq 0 ]; then
      touch ${LOCKFILE}
      success
   else
      failure
   fi
   echo
   return ${RETVAL}
}

case "$1" in
start)
start
;;
stop)
stop
;;
status)
echo "Not applied to service"
;;
restart)
stop
start
;;
reload)
echo "Not applied to service"
;;
condrestart)
#
echo "Not applied to service"
;;
probe)
;;
*)
echo "Usage: SystemEmail{start|stop|status|reload|restart[|probe]"
exit 1
;;

esac
exit ${RETVAL}

uptime-check.sh

#!/usr/bin/env bash
#
# uptime-check.sh
# Check uptime and mail if uptime is less than it was when script last ran
# http://linux-101.org
#
 
HOSTNAME=$(hostname)
HDRFROM="From: Uptime Script <devnull@example.com>"
HDRTO="To: Sysadmin <alerts@example.com>"
HDRSUBJ="Subject: $HOSTNAME has been rebooted"
ENVELTO="alerts@example.com"  #Match above HDRTO
 
PWD=$(pwd)
DATE=$(date '+%Y%m%d%H%M%S')
DATAFILE=$PWD/uptime-check.data
UPTIMENEW=$(gawk -F . '{ print $1 }' /proc/uptime)
UPTIMEOLD=$(gawk -F : '{ print $2 }' $DATAFILE)
 
if [ "$UPTIMENEW" -lt $UPTIMEOLD ] ; then
    TMPFILE=/var/tmp/uptime.tmp
    touch $TMPFILE
    echo $HDRFROM >> $TMPFILE
    echo $HDRTO >> $TMPFILE
    echo $HDRSUBJ >> $TMPFILE
    echo "uptime | ps aux | netstat -nap" >> $TMPFILE
    echo " " >> $TMPFILE
    $(uptime >> $TMPFILE)
    echo "
           " >> $TMPFILE
    $(ps aux >> $TMPFILE)
    echo "
           " >> $TMPFILE
    $(netstat -nap >> $TMPFILE)
    echo "
           " >> $TMPFILE
    echo "." >> $TMPFILE
    echo "
           " >> $TMPFILE
    cat $TMPFILE | sendmail "$ENVELTO"
    rm -f $TMPFILE
    echo "$DATE:$UPTIMENEW" > $DATAFILE
else
    echo "$DATE:$UPTIMENEW" > $DATAFILE
fi

Then all you have to do is run the following commands as root (or elevate with sudo):

1.make it executable with chmod u+x email.sh
2.copy it to init.d with cp email.sh /etc/init.d/
3.make root have ownership of the file with chown root:root email.sh
4.set it to run automatically via update-rc.d email.sh start 98 2 3 4 5 . stop 02 0 1 6 .

If you want to remove the script you can do so by using sudo update-rc.d -f email.sh remove

You can also test that it is running after step 1 by running ./email.sh start and ./email.sh stop