A Centreon/Nagios Plugin for the Pi-hole API

#!/bin/bash
# Nagios plugin to work with Pihole API
########### By @deividgdt ###########
plugin_version="1.3"
#####################################

function info() {
	case "$1" in
		token)
			echo "[i] The file ${api_token_file} does not exist or it's empty."
			echo "[i] You can get your token from the value WEBPASSWORD in the file /etc/pihole/setupVars.conf"
			echo "[i] Just put in the file ${api_token_file} and that's it."
			echo ""
			echo "[i] Example:"
			echo "	centreon-engine@centreon # touch ${api_token_file}"
			echo "	centreon-engine@centreon # echo 'PASTE_YOUR_TOKEN_HERE' >> ${api_token_file}"
			exit 1;
		;;
		usage)
			echo "[i] Usage $0 -h pihole_ipaddress -s [ clients || queries || ads ] || -i || -q"
			echo ""
			echo "[i] -s (summary)"
			echo "	- clients: Number of clients using Pihole as their DNS server"
			echo "	- queries: Number of DNS queries"
			echo "	- ads: Number and percentage of ads blocked."
			echo ""
			echo "[i] -i (information)"
			echo "	- show the version of the plugin"
			echo "[i] -q"
			echo "	- queries by type AAAA, A, SOA, TXT, PTR, ANY, SRV, IPV4, IPV6"
		;;
		version)
			echo "[v] plugin by @deividgdt https://github.com/deividgdt - version: ${plugin_version}"
		;;
	esac
}

function apiCall() {
	local obj=$1
	local token=$2
	
	pihole_api_tempfile="/usr/lib/nagios/plugins/pihole_api.tmp"
	
	case $obj in 
		"summary")
			pihole_api_output=$(curl http://${pihole_ipadd}/admin/api.php?${obj} 2> /dev/null | sed 's/","/n/g ; s/"//g' > ${pihole_api_tempfile})
		;;
		"getQueryTypes")
			pihole_api_output=$(curl "http://${pihole_ipadd}/admin/api.php?${obj}&auth=${token}" 2> /dev/null | sed "s,),,g ; s,(,,g ; s/,"/n/g ; s/"//g" > ${pihole_api_tempfile})
		;;
	esac
}

function getApiToken() {
	# Default token file location
	api_token_file="/usr/lib/nagios/plugins/apihole.token"
	
	# If the file does not exist
	if [ ! -f ${api_token_file} ]; then
		info token
	else
		export api_token=$(cat ${api_token_file})
		# If the the api_token var is NULL because the file is empty (?)
		if [ -z ${api_token} ]; then 
			echo "[e] Token is NULL"; 
			info token 
		fi
	fi
}

function functSummary() {
	apiCall "summary"
	# The summary option passed
	case "${summary_opt}" in
		clients)	
			unique_clients=$(cat ${pihole_api_tempfile} | grep unique_clients | cut -f2 -d":")
			echo "THERE ARE ${unique_clients} HOSTS UP|Total=${unique_clients}"
		;;
		queries)	
			dns_queries_today=$(cat ${pihole_api_tempfile} | grep dns_queries_today | cut -f2 -d":")
			echo "DNS QUERIES TODAY ${dns_queries_today}|Total=${dns_queries_today}"
		;;
		ads)		
			ads_percentage_today=$(cat ${pihole_api_tempfile} | grep ads_percentage_today | cut -f2 -d":")
			ads_blocked_today=$(cat ${pihole_api_tempfile} | grep ads_blocked_today | cut -f2 -d":")
			echo "ADS BLOCKED TODAY ${ads_blocked_today} , PERCENTAGE = ${ads_percentage_today} %|Total=${ads_blocked_today} Percentage=${ads_percentage_today}%"
		;;
		
		*)
			echo "Incorrect arugment > ${summary_opt} < for the option -s";
			info "usage"
			exit 1;
		;;
	esac
}

function functGetQueryTypes() {
	# This function requires a token
	getApiToken
	
	# Calling the api
	apiCall "getQueryTypes" "${api_token}"
	
	# Local vars for query types
	local ipv4=$(cat ${pihole_api_tempfile} | grep -io "ipv4:.*" | cut -f2 -d":")
	local ipv6=$(cat ${pihole_api_tempfile} | grep -io "ipv6:.*" | cut -f2 -d":")
	local any=$(cat ${pihole_api_tempfile} | grep -io "any:.*" | cut -f2 -d":")
	local srv=$(cat ${pihole_api_tempfile} | grep -io "srv:.*" | cut -f2 -d":")
	local soa=$(cat ${pihole_api_tempfile} | grep -io "soa:.*" | cut -f2 -d":")
	local ptr=$(cat ${pihole_api_tempfile} | grep -io "ptr:.*" | cut -f2 -d":")
	local txt=$(cat ${pihole_api_tempfile} | grep -io "txt:.*" | sed 's,},,g' | cut -f2 -d":")
	
	echo "NUMBER OF QUERIES BY TYPE IPV4=${ipv4} , IPV6=${ipv6} , ANY=${any} , SRV=${srv} , SOA=${soa} , PTR=${ptr} , TXT=${txt}|IPV4=${ipv4} IPV6=${ipv6} ANY=${any} SRV=${srv} SOA=${soa} PTR=${ptr} TXT=${txt}"
	
}

if [ $# -eq 0 ]; then
	info "usage"
	exit 1;
fi

# The options passed by the user
while getopts "h:s:iq" opt; do
	case "$opt" in
		h ) 
			pihole_ipadd=$OPTARG						;;
		s ) 
			summary_selected="y"
			summary_opt=$OPTARG							;;
		q ) 
			query_type_selected="y" 					;;
		i ) 
			info "version"
			exit 0										;;
		?) 
			echo "[e] Invalid option. -$OPTARG" 
			exit 1										;;
	esac
done

# The values passed by the user
if [ -z ${pihole_ipadd} ]; then 
	echo "[i] Please enter the Pihole IP address as follow: -h pihole_ipaddress"; 
	exit 1;
else
	if [[ "${summary_selected}" == "y" ]]; then
		# Calling the summary function
		functSummary
		exit 1;
	elif [[ "${query_type_selected}" == "y" ]]; then
		# Calling the Query Types funct
		functGetQueryTypes
	else
		info "usage"
	fi
	
	# Just delete the temp file
	rm -f ${pihole_api_tempfile}
fi

./check_pihole_api -h $PIHOLE_IPADDRESS -s [ clients || queries || ads ] || -i || -q || -t

[i] -s (summary)
	- clients: Number of clients using Pihole as their DNS server
	- queries: Number of DNS queries
	- ads: Number and percentage of ads blocked.

[i] -i (information)
	- show the version of the plugin

[i] -q
	- queries by type AAAA, A, SOA, TXT, PTR, ANY, SRV, IPV4, IPV6

[i] -t
  - Show a TOP number of queries by host

./check_pihole_api -h $PIHOLE_IPADDRESS -t
TOP NUMBER OF QUERIES BY HOST portatil1.pihome=5678 movil1.pihome=4442 movil2.pihome=3556 portatil2.pihome=2280 samsungtv.pihome=1942| portatil1.pihome=5678 movil1.pihome=4442 movil2.pihome=3556 portatil2.pihome=2280 samsungtv.pihome=1942