#!/bin/bash

#==========================================================
# This script checks if your servers are up and running. If
# server is down it sends an email to the email(s) listed in 
# $EMAIL.
# The script requires you to have `mailx` setup.
#==========================================================

# Set connect timeout to 1min
TIMEOUT=60

# Receiver Email. Can be a comma separated list of emails.
EMAIL='me@mail.com'

function getStatusCode {
  local result=$1
  local host=$2
  local cmd="curl --connect-timeout $TIMEOUT -s -o /dev/null -w \"%{http_code}\" $host"
  eval $result=$($cmd)
}

function checkCode {
  local code=$1
  local host=$2

  if [ $code != '200' -a $code != '302' ]
  then 
    sendEmail "Server at $host is down."
  else 
    echo "Server at $host is up."
  fi
}

function sendEmail {
  local msg=$1
  echo $msg | mailx -A gmail -s "Server Report" $EMAIL
}

function isUp {
  local host=$1
  getStatusCode code $host
  checkCode $code $host
}

#==========================================================
# Define your servers here:
#==========================================================

SERVERS=(\
'http://server1.com' \
'http://server2.com' \
)

for server in ${SERVERS[@]}
do
  isUp $server
done