#!/bin/bash

# (c) Matteo Corti, ETH Zurich, 2007
#
# check_nagios_latency
#
# Checks the Nagios latency

VERSION=0.9.3

################################################################################
# Functions

################################################################################
# Prints usage information
# Params
#   $1 error message (optional)
usage() {

    if [ -n "$1" ] ; then
        echo "Error: $1" 1>&2
    fi
    
    echo
    echo "Usage: check_nagios_latency [-hvV?] -w warning -c critical [-n path]"
    echo
    echo "   -c         critical threshold"
    echo "   -h, -?     this help message"
    echo "   -n path    nagiostats path"
    echo "   -v         verbose output"
    echo "   -w         warning threshold"
    echo "   -V         version"
    echo
    echo "Report bugs to: Matteo Corti <matteo.corti@id.ethz.ch>"
    echo

    exit 3

}

################################################################################
# Checks if a given program is available and executable
# Params
#   $1 program name
check_prog() {

    if [ -z "$PROG" ] ; then
        PROG=`which $1`
    fi

    if [ -z "$PROG" ] ; then
        echo "LATENCY CRITICAL - cannot find $1"
        exit 2
    fi

    if [ ! -x "$PROG" ] ; then
        echo "LATENCY CRICTICAL - $PROG is not executable"
        exit 2
    fi

}

################################################################################
# Main
################################################################################

# process command line options
while getopts "vh?Vc:w:n:" opt; do
    case $opt in
        c )      CRITICAL=$OPTARG;  ;;
        h | \? ) usage ; exit 3;    ;;
        n )      PROG=$OPTARG ;;
        V )      echo "check_nagios_latency version ${VERSION}"; exit 3; ;;
        v )      VERBOSE=1;         ;;
        w )      WARNING=$OPTARG;   ;;
    esac
done
shift $(($OPTIND - 1))

################################################################################
# sanity checks

###############
# Check options
if [ -z "${CRITICAL}" ] ; then
    usage "No critical threshold specified"
fi
if [ -z "${WARNING}" ] ; then
    usage "No warning threshold specified"
fi

######################
# Check number formats

if ! echo $WARNING | grep -qE '^[0-9]+(\.[0-9]+)?$' ; then
    echo "LATENCY UNKOWN - Wrong number: $WARNING"
    exit 3
fi

if ! echo $CRITICAL | grep -qE '^[0-9]+(\.[0-9]+)?$' ; then
    echo "LATENCY UNKOWN - Wrong number: $WARNING"
    exit 3
fi

#######################
# Check needed programs

check_prog nagiostats

LATENCY=`$PROG | grep "Active Service Latency" |cut -f3 -d'/' | awk '{print $1}' | tr -d '\n'`;

if [ -n "${VERBOSE}" ] ; then echo "latency: ${LATENCY}"; fi

####################
# Perform the checks

PERF="Latency=${LATENCY};${WARNING};${CRITICAL};;"

COMPARISON=`echo "if($LATENCY>$CRITICAL) 1 else 0;" | bc`
if [ $COMPARISON -eq 1 ] ; then
    echo "LATENCY CRITICAL ${LATENCY}s | $PERF"
    exit 2
fi

COMPARISON=`echo "if($LATENCY>$WARNING) 1 else 0;" | bc`
if [ $COMPARISON -eq 1 ] ; then
    echo "LATENCY WARNING ${LATENCY}s | $PERF"
    exit 1
fi

echo "LATENCY OK ${LATENCY}s| $PERF"
exit 0;