#!/bin/bash

##############################################################################
# Bash script written by Vahid Hedayati April 2013
# Nagalert can be run as a service on your device so it auto 
# schedules nagios downtime and also cancels schedule if start is run
# This can work in conjunction of
# https://github.com/vahidhedayati/nagios-disable-host-notifications
# Which emails out any notifications - scheduled down time in 
# html email clickable format
###############################################################################
# DOWNLOAD THIS SCRIPT AND PLACE IN: /etc/init.d/
# chmod +x /etc/init.d/nagalert
# sudo /sbin/chkconfig nagalert on
# and before you enjoy !
# DON'T FORGET TO CONFIGURE NAGIOS SERVER DETAILS BELOW DISCLAIMER HAHA
##############################################################################
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
##############################################################################

PATH="${PATH:+$PATH:}/usr/sbin:/sbin"

## Ensure you provide your nagios server name username and admin password 
# and ensure url matches your nagios cgi-bin path
username="nagiosadmin"
password="password"
naghost="nagios.your.server.com"
base_url="http://$username:$password@"$naghost"/nagios/cgi-bin"

# Now this is how long you want your default if not defined time value to be
# 10 M = 10 Minutes You can set a numeric value followed by M Minutes, H Hours or D  Days 
DEFAULT_TIME="10M"

# These two are the input values but depending on call 
# if stop it can be 2 values after stop - so stop 10M {hostname} -
# start is always one extra value start {hostname} 
# {hostname always optional - non given it gets set to current host executing nagalert
val2=$2;
val3=$3;

# Tmp file created with random id just incase other are executing nagalert
# at the same time - the file is used only when starting service which disables enabled notifications
# The tmp file stores the wget content of downtime link on the web interface called by parseHTML
RAND="$$";
tmpfile="/tmp/nagios-status.html.$RAND"


#######################################################################################
#  MAIN CODE
#######################################################################################
# Set date changes user input of 10M to 10 minutes and returns it in format understood
# by nagios html web front end used by init_stop
function set_date() { 
	if [[ $input_time =~ D ]]; then
        	input_time=$(echo $input_time|sed -e 's/D/ days/g')
	elif [[ $input_time =~ M ]]; then
        	input_time=$(echo $input_time|sed -e 's/M/ minutes/g')
	elif [[ $input_time =~ H ]]; then
        	input_time=$(echo $input_time|sed -e 's/H/ hours/g')
	elif [[ $input_time =~ S ]]; then
        	input_time=$(echo $input_time|sed -e 's/S/ SECONDS/g')
	fi
	amp="%%3A"
	now=$(date +%m-%d-%Y"+"%H$amp%M$amp%S)
	end=$(date +%m-%d-%Y"+"%H$amp%M$amp%S  -d "$input_time")
}


# This initialises the stop function by setting hostname and input time values
# calls above to generate nagios format start end dates
function init_stop() { 
	input_time=$val2;
	if [ "$input_time" == "" ]; then
		input_time=$DEFAULT_TIME
	fi
	set_date
	HOST_NAME=$val3;
	# If no hostname set in either start/stop make it this host
	if [ "$HOST_NAME" == "" ]; then
		HOST_NAME=(`hostname -s`)
	fi
}

# This initialises start variables
function init_start() { 
	HOST_NAME=$val2;
	# If no hostname set in either start/stop make it this host
	if [ "$HOST_NAME" == "" ]; then
		HOST_NAME=(`hostname -s`)
	fi
}

# This works out who is logged in - if not found it will use root
# also try capture their real name if defined properly in passwd entry
function script_user() { 
      echo $(logname)  | grep "[a-z]" > /dev/null
      if [ $? = 0 ]; then
          loginname=$(logname);
      else
	  loginname="root";
      fi
      person=$(getent  passwd $loginname|awk -F":" '{print $5}')
      userlogin=$loginname;
}

# This is the main core function of start service
# it simply parses for hostname in downtime link of nagios web interface
# It then generates relevant links and wgets them to enable alerts
function parseHTML() {
	IFS=$'\n'
	go=0;
	return_string="";
	start="<TABLE BORDER=0 CLASS='downtime'>";
	fin="</TABLE>";
	surl="$base_url/cmd.cgi?cmd_typ=79&cmd_mod=2&down_id="
	hurl="$base_url/cmd.cgi?cmd_typ=78&cmd_mod=2&down_id="
	wget -q "$base_url/extinfo.cgi?type=6" -O $tmpfile
	for lines in $(cat $tmpfile); do
        	if [[ $lines =~ "$start" ]]; then go=1; fi
        	if [[ $lines =~ "$fin" ]]; then go=0; fi
        	if [[ $go == 1 ]]; then
                	if [[ $lines =~ "$HOST_NAME</A>" ]]; then
				return_string="Enabling Nagios Alerts for $HOST_NAME";
                        	if [[ $lines =~ "downtimeOdd" ]]; then
                                	if [[ $lines =~ "service" ]]; then
                                        	servicedownid=$(echo $lines|awk -F"downtimeOdd" '{print $12}'|awk -F">" '{print $2}'|awk -F"<" '{print $1}')
						url="$surl$servicedownid"
						echo "Enabling SERVICEID:$servicedownid Alert $url";
						wget -O - -q -t 1 "$url" >/dev/null 2>&1
                                	else
                                       		hostdownid=$(echo $lines|awk -F"downtimeOdd" '{print $11}'|awk -F">" '{print $2}'|awk -F"<" '{print $1}')
						url="$hurl$hostdownid"
						echo "Enabling HOSTDOWNID:$hostdownid Alert $url";
						wget -O - -q -t 1 "$url" >/dev/null 2>&1
                                	fi
                        	fi
                        	if [[ $lines =~ "downtimeEven" ]]; then
                                        if [[ $lines =~ "service" ]]; then
                                                servicedownid=$(echo $lines|awk -F"downtimeEven" '{print $12}'|awk -F">" '{print $2}'|awk -F"<" '{print $1}')
                                                url="$surl$servicedownid"
                                                echo "Enabling SERVICEID:$servicedownid Alert $url";
                                                wget -O - -q -t 1 "$url" >/dev/null 2>&1
                                        else
                                                hostdownid=$(echo $lines|awk -F"downtimeEven" '{print $11}'|awk -F">" '{print $2}'|awk -F"<" '{print $1}')
                                                url="$hurl$hostdownid"
                                                echo "Enabling HOSTDOWNID:$hostdownid Alert $url";
                                                wget -O - -q -t 1 "$url" >/dev/null 2>&1
                                        fi
                                fi
                        else
				return_string="No pattern matching $HOST_NAME was found on $naghost"
                	fi
        	fi
	done
	echo $return_string
	rm $tmpfile
}

# This is used by the stop function 
# It calls the nagios web front end ur's and sets up comments to disable alerts
function stop_nagging() { 
	script_user
        message="$userlogin aka $person Disabled Nagios SERVICE Alerts for $HOST_NAME for $input_time";
        echo $message
	url="$base_url/cmd.cgi?cmd_typ=86&cmd_mod=2&host=$HOST_NAME&com_data=$message&trigger=0&start_time=$now&end_time=$end&fixed=1&hours=0&minutes=0&btnSubmit=Commit"
	wget -O - -q -t 1 "$url" >/dev/null 2>&1
	message="$userlogin aka $person Disabled Nagios HOST Alert for $HOST_NAME for $input_time";
        echo $message
	url1="$base_url/cmd.cgi?cmd_typ=55&cmd_mod=2&host=$HOST_NAME&com_data=$message&trigger=0&start_time=$now&end_time=$end&fixed=1&hours=0&minutes=0&childoptions=0&btnSubmit=Commit"
	wget -O - -q -t 1 "$url1" >/dev/null 2>&1	
}

# Help option to return help
function usage() { 
 	echo "$0  stop {10M|10H|10D)"
 	echo "$0 start "
 	echo "----------------------------------"
 	echo "stop value ie 10S for 10 Seconds" 
 	echo "stop value ie 10M for 10 Minutes"
 	echo "stop value ie 10H for 10 Hours" 
 	echo "stop value ie 10D for 10 Days" 
 	echo "----------------------------------"
}





# Main program case function
case "$1" in
  start)
		init_start;
                parseHTML;
		;;
  stop)
		init_stop;
		stop_nagging		
		 ;;
  *)
	usage
	exit 1
esac

exit 0