#!/bin/sh
# File: /usr/lib64/nagios/plugins/check_apache_threads
# Author: bgstack15@gmail.com
# Startdate: 2017-01-09 15:53
# Title: Nagios Check for Apache Threads
# Purpose: For a troublesome dmz wordpress host
# Package: nagios-plugins-apache-threads
# History:
# Usage:
#    In nagios/nconf, use this checkcommand check command line: $USER1$/check_by_ssh -H $HOSTADDRESS$ -C "$USER1$/check_apache_threads -w $ARG1$ -c $ARG2$"
# Reference: general design /usr/lib64/nagios/plugins/check_sensors
#    general design http://www.kernel-panic.it/openbsd/nagios/nagios6.html
#    case -w http://www.linuxquestions.org/questions/programming-9/ash-test-is-string-a-contained-in-string-b-671773/
# Improve:

PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin

PROGNAME=`basename $0`
PROGPATH=`echo $0 | sed -e 's,[\\/][^\\/][^\\/]*$,,'`
REVISION="0.0.1"

. $PROGPATH/utils.sh


print_usage() {
   cat <<EOF
Usage: $PROGNAME -w <thresh_warn> -c <thresh_crit>
EOF
}

print_help() {
   print_revision $PROGNAME $REVISION
   echo ""
   print_usage
   echo ""
   echo "This plugin checks for the number of active apache threads."
   echo ""
   support
   exit $STATE_OK
}


# MAIN

# Total httpd threads
tot_apache_threads="$( ps -ef | grep -ciE "httpd$" )"
verbosity=0
thresh_warn=
thresh_crit=

while test -n "${1}";
do
   case "$1" in
      --help|-h)
         print_help
         exit $STATE_OK
         ;;
      --version|-V)
         print_revision $PROGNAME $REVISION
         exit $STATE_OK
         ;;
      -v | --verbose)
         verbosity=$(( verbosity + 1 ))
         shift
         ;;
      -w | --warning | -c | --critical)
         if [[ -z "$2" || "$2" = -* ]];
         then
            # Threshold not provided
            echo "$PROGNAME: Option '$1' requires an argument."
            print_usage
            exit $STATE_UNKNOWN
         elif [[ "$2" = +([0-9]) ]];
         then
            # Threshold is a number
            thresh="$2"
         # use for a percentage template, from reference 2
         #elif [[ "$2" = +([0-9])% ]]; then
         #   # Threshold is a percentage
         #   thresh=$(( tot_mem * ${2%\%} / 100 ))
         else
            # Threshold is not a number or other valid input
            echo "$PROGNAME: Threshold must be an integer."
            print_usage
            exit $STATE_UNKNOWN
         fi
         case "$1" in *-w*) thresh_warn=$thresh;; *) thresh_crit=$thresh;; esac
         shift 2
         ;;
      -?)
         print_usage
         exit $STATE_OK
         ;;
      *)
         echo "$PROGNAME: Invalid option '$1'"
         print_usage
         exit $STATE_UNKNOWN
         ;;
   esac
done

if test -z "$thresh_warn" || test -z "$thresh_crit";
then
   # One or both values were unspecified
   echo "$PROGNAME: Threshold not set"
   print_usage
   exit $STATE_UNKNOWN
elif test "$thresh_crit" -le "$thresh_warn";
then
   echo "$PROGNAME: Critical value must be greater than warning value."
   print_usage
   exit $STATE_UNKNOWN
fi

if test "$verbosity" -ge 2;
then
   # Print debugging information
   /bin/cat <<EOF
Debugging information:
   Warning threshold: $thresh_warn
   Critical threshold: $thresh_crit
   Verbosity level: $verbosity
   Apache threads: ${tot_apache_threads}
EOF
fi

if test "${tot_apache_threads}" -gt "${thresh_crit}";
then
   # too many apache threads
   echo "APACHE CRITICAL - $tot_apache_threads"
   exit $STATE_CRITICAL
elif test "${tot_apache_threads}" -gt "${thresh_warn}";
then
   echo "APACHE WARNING - $tot_apache_threads"
   exit $STATE_WARNING
else
   # fine
   echo "APACHE OK - $tot_apache_threads"
   exit $STATE_OK
fi