#!/bin/bash
# This Script counts the number of times a certain error code appears and report the respective error level . Note:  It is dependent on logtail 
# Author Alex Nyika Omuyonga 22/10/2014

#function to display correct usage help 
function usage(){
cat <<EOF
This script is used by nagios to check the number of times a certain error code appears
in the apache access log and  then report that with the respective error level. 
Usage: $0  -e <erro code> -c <critical threshold> -w <warning threshold>  /valid/path/to/apache/access/log/file
	Options:
		-e: The error code to look for ; e.g. -e 500
		-c: The number of times the error occurs to deem the situation critical ; e.g -c 200 
		-w: The warning threshold ; e.g. -w 20 
		-l: A valid path to the apache access log file ; e.g. /var/log/httpd/access_log 
EOF
}

#The variables that we shall work with 

#The thresholds
#Warning
W=
#Critical
C=

#The error code
E=

#The path/to/apache/access/log/file
path=

#The count of  number of codes counted
count= 

function run(){
      if [ $C -lt $count ] ; then
      echo 'Critical: Error Code:'$E' Errors: '$count
      exit 2
      elif [ $W -lt $count ]
      then
      echo 'Warning, Error Code:'$E' Errors: '$count
      exit 1
      else
      echo "Ok: Error Code:"$E "Errors:"$count
      exit 0
      fi
}

#pick sent variables 
while getopts "e:w:c:l:" OPTION
do
  case $OPTION in
    e)
     E=$OPTARG
     ;;
	w)
     W=$OPTARG
     ;;
   c)
     C=$OPTARG
     ;;
   l)
   path=$OPTARG
   ;;
   ?)
     usage
     exit
     ;;
  esac
done


# Test to see if we have all the required parameters 

#check if the user entered all variables
if [[ -z $E ]] || [[ -z $W ]] || [[ -z $C ]]  || [[ -z $path ]]
then
    usage
   exit 1
fi

# Check and see that the log file provided exits. If yes then go on to check 

if [ -f $path ] ; then
count=$(logtail $path | grep -c 'HTTP/1.1" '$E)
run
else
echo "Log  file not found in "$path
exit 1		
fi