#!/bin/bash

# Nagios monitor script to check current apache vitals
# Liam - 12/04/07

UTILS=/usr/lib/nagios/plugins/utils.sh
# utils.sh
if [ -f $UTILS ]; then . $UTILS; else echo "Error: utils.sh not found" && exit 3; fi

VERSION=1.0.8

# --------------------------------------
# Functions

# requests function
requests() {

	check

	# Obtain data from /server-status
	REQUESTS=`curl -s $HOST/server-status | grep 'processed' | head -n 1 | awk -F \> '{ print $2 }' | awk '{ print $1 }'`
	if [[ $REQUESTS =~ ^[-+]?[0-9]+\(\.[0-9]+\)?$ || $REQUESTS = "" ]]; then
		echo "Error: Unreadable output from $HOST/server-status - check that it is accessible"
		exit 3
	fi
	
	if [[ $REQUESTS -gt $CRITICAL ]]
	then
		echo "CRITICAL: Current requests ($REQUESTS) exceeds threshold of $CRITICAL"
		exit $STATE_CRITICAL
	elif [[ $REQUESTS -gt $WARNING ]]
	then
		echo "WARNING: Current requests ($REQUESTS) exceeds threshold of $WARNING"
		exit $STATE_WARNING
	else
		echo "Current requests: $REQUESTS"
		exit $STATE_OK
	fi
}

# idle worker function
idle() {

	check

	# Obtain data from /server-status
	IDLE=`curl -s $HOST/server-status | grep 'idle' | head -n 1 | awk '{ print $6 }'`
	if [[ $IDLE =~ ^[-+]?[0-9]+\(\.[0-9]+\)?$ || $IDLE = "" ]]; then
		echo "Error: Unreadable output from $HOST/server-status - check that it is accessible"
		exit 3
	fi
	
	if [[ $IDLE -lt $CRITICAL ]]
	then
		echo "CRITICAL: Current idle workers ($IDLE) falls below threshold of $CRITICAL"
		exit $STATE_CRITICAL
	elif [[ $IDLE -lt $WARNING ]]
	then
		echo "WARNING: Current idle workers ($IDLE) falls below threshold of $WARNING"
		exit $STATE_WARNING
	else
		echo "Current idle workers: $IDLE"
		exit $STATE_OK
	fi
}

# requests per second function
rps() {

	check

	# Obtain data from /server-status
	RPS=`curl -s $HOST/server-status | grep 'kB' | head -n 1 | awk -F \> '{ print $2 }' | awk '{ print $1 }'`
	if [[ $RPS =~ ^[-+]?[0-9]+\(\.[0-9]+\)?$ || $IDLE = "" ]]; then : ; else
		echo $RPS - invalid
		echo "Error: Unreadable output from $HOST/server-status - check that it is accessible"
		exit 3
	fi
	
	if [[ $RPS -gt $CRITICAL ]]
	then
		echo "CRITICAL: Requests per second ($RPS) exceeds threshold of $CRITICAL"
		exit $STATE_CRITICAL
	elif [[ $RPS -gt $WARNING ]]
	then
		echo "WARNING: Requests per second ($RPS) exceeds threshold of $WARNING"
		exit $STATE_WARNING
	else
		echo "Requests per second: $RPS"
		exit $STATE_OK
	fi
}

# data throughput function
data() {

	check

	# Obtain data from /server-status
	DATA=`curl -s $HOST/server-status | grep 'kB' | head -n 1 | awk -F \> '{ print $2 }' | awk '{ print $4 }'`
	if [[ $DATA =~ ^[-+]?[0-9]+\(\.[0-9]+\)?$ || $DATA = "" ]]; then
		echo "Error: Unreadable output from $HOST/server-status - check that it is accessible"
		exit 3
	fi
	
	if [[ $DATA -gt $CRITICAL ]]
	then
		echo "CRITICAL: Data throughput ($DATA MB/s) exceeds threshold of $CRITICAL"
		exit $STATE_CRITICAL
	elif [[ $DATA -gt $WARNING ]]
	then
		echo "WARNING: Data throughput ($DATA MB/s) exceeds threshold of $WARNING"
		exit $STATE_WARNING
	else
		echo "Data throughput: $DATA MB/s"
		exit $STATE_OK
	fi
}

usage() {
print_revision
cat << EOF

`basename $0` version $VERSION

Usage: `basename $0` -H host [-W warn] [-C crit] [-r -i -s -d]
POSIX options:
        -H hostname             Required: Hostname or IP of server
        -W [warning]            Required: Warning level - numerical
        -C [critical]           Required: Critical level - numerical
Function toggles:  (use only one)
        -r                      Requests the server is currently processing
        -i                      Idle worker threads
        -s                      Requests served per second
        -d                      Data throughput of server

Example:
`basename $0` -H httpd.apache.org -W 500 -C 750 -r
EOF
exit 3
}

check() {
	# Check to see the vitals have been provided
	if [[ ! $HOST || ! $WARNING || ! $CRITICAL ]]
	then 
		echo "Error: Vital information omitted" 
		echo
		usage
	fi

	# Test that the host is reachable
	ping -c 1 $HOST &> /dev/null
	if [ $? -gt 0 ]
	then
		echo "Error: Host $HOST is unreachable"
		exit 3
	fi
}

# --------------------------------------

if [[ $@ = "" ]]; then
usage
fi
x=1
while getopts "H:W:C:risd" opt; do
	case "$opt" in
		H) # Host to check
			HOST="$OPTARG"
		;;
		W) # Warning level
			WARNING="$OPTARG"
		;;
		C) # Critical level
			CRITICAL="$OPTARG"
		;;
		r) # Requests currently being processed
			requests
		;;
		i) # Idle worker processes
			idle
		;;
		s) # Requests per second
			rps
		;;
		d) # Data throughput
			data
		;;
		*) # Usage
			usage
		;;
	esac
	x=$OPTIND
done
shift $((x-1))