#!/bin/sh

set -e

: << =cut

=head1 NAME

adguardhome - Monitor dns queries

=head1 APPLICABLE SYSTEMS

AdGuardHome instances

=head1 CONFIGURATION

On a low traffic AdGuardHome instance you may want to lower 
querylog_size_memory parameter in AdGuardHome configuration, otherwise 
there won't be enough data for munin graphs.

 log      - Querylog file of AdGuardHome
 interval - Interval of munin cronjob in minutes
 binary   - Path to AdGuardHome binary

 [adguardhome_dns]
 env.log /opt/AdGuardHome/data/querylog.json
 env.interval 5
 env.binary /opt/AdGuardHome/AdGuardHome

=head1 AUTHOR

Copyright (C) 2020 Sebastian L. (https://momou.ch)

=head1 LICENSE

GPLv2

=head1 MAGIC MARKERS

 #%# family=auto
 #%# capabilities=autoconf

=cut

. "$MUNIN_LIBDIR/plugins/plugin.sh"

RECORDS="A AAAA ANY CNAME MX NS NXDOMAIN PTR SIG SOA SRV TXT"
CLIENTS="dns doh dot"

case $1 in

    autoconf)
        if [ -x "${binary:-/opt/AdGuardHome/AdGuardHome}" ]; then
            if [ -z "$(command -v AdGuardHome)" ]; then
                echo "no (AdGuardHome not found)"
                exit 0
            else
                echo "yes"
                exit 0
            fi
        else
            echo "no (/opt/AdGuardHome/AdGuardHome not found)"
            exit 0
        fi
        ;;

   config)
        echo "multigraph adguardhome_queries"
        echo "graph_title AdGuardHome - DNS Queries"
        echo "graph_info DNS Queries made over AdGuardHome"
        echo "graph_args -Y -A -l 0"
        echo "graph_category network"
        echo "graph_vlabel queries"
        echo "queries.label Queries"
        echo "queries.info All queries"
        echo "queries.min 0"
        echo "blocked.label Blocked"
        echo "blocked.info Blocked queries by filterlist"
        echo "blocked.min 0"
        echo "parental.label Parental"
        echo "parental.info Blocked by parental filter"
        echo "parental.min 0"
        echo "safesearch.label Safe search"
        echo "safesearch.info Filtered for safe searching"
        echo "safesearch.min 0"
        echo "safebrowsing.label Safe browsing"
        echo "safebrowsing.info Filtered for safe browsing"
        echo "safebrowsing.min 0"
        echo "multigraph adguardhome_avgproc"
        echo "multigraph adguardhome_query_types"
        echo "graph_title AdGuardHome - Query types"
        echo "graph_info Query types made by AdGuardHome"
        echo "graph_vlabel query types"
        echo "graph_args -Y -A -l 0"
        echo "graph_category network"
        for KEY in $RECORDS; do
                echo "$KEY.label $KEY"
                echo "$KEY.info $KEY"
                echo "$KEY.min 0"
        done
        echo "multigraph adguardhome_client_protos"
        echo "graph_title AdGuardHome - Client protocols"
        echo "graph_info Client protocols used on AdGuardHome"
        echo "graph_vlabel client protocols"
        echo "graph_args -A -Y -l 0"
        echo "graph_category network"
        for KEY in $CLIENTS; do
		echo "$KEY.label $KEY"
		echo "$KEY.info $KEY"
		echo "$KEY.min 0"
	done
        echo "multigraph adguardhome_avgproc"
        echo "graph_title AdGuardHome - Processing time (ms)"
        echo "graph_info Average processing time of queries in miliseconds"
        echo "graph_vlabel average processing (ms)"
        echo "graph_args -A -Y -l 0"
        echo "graph_category network"
        echo "avgproc.label Average processing time (ms)"
        echo "avgproc.info Average processing time in miliseconds"
        echo "avgproc.min 0"
        exit 0

        ;;

esac

INTERVAL=$(date -d "${interval:-5} minutes ago" +%FT%H:%M)
LOGDATA=$(sed -ne "s/^\\(.*\\)\\($INTERVAL\\)/\\1\\2/p" "${log:-"/opt/AdGuardHome/data/querylog.json"}")

if [ -z "$LOGDATA" ]; then

	for VALUE in queries blocked safesearch safebrowsing parental "$RECORDS" "$CLIENTS" avgproc; do
		export $VALUE="U"
	done

else

	# See internal/filtering.go in AdGuardHome sources
	# Reason 0 = NotFilteredNotFound
	# Reason 1 = NotFilteredAllowList
	# Reason 2 = NotFilteredError
	# Reason 3 = FilteredBlockList
	# Reason 4 = FilteredSafeBrowsing
	# Reason 5 = FilteredParental
	# Reason 6 = FilteredInvalid
	# Reason 7 = FilteredSafeSearch
	# Reason 8 = FilteredBlockedService
	queries=$(echo "$LOGDATA" | grep -o \"QT\": | wc -l)
	blocked=$(echo "$LOGDATA" | grep -o '\"Reason\":[3,5,8]' | wc -l)
	safesearch=$(echo "$LOGDATA" | grep -o \"Reason\":7 | wc -l)
	safebrowsing=$(echo "$LOGDATA" | grep -o \"Reason\":4 | wc -l)
	parental=$(echo "$LOGDATA" | grep -o \"Reason\":5 | wc -l)

	for KEY in $RECORDS; do
		export $KEY="$(echo "$LOGDATA" | grep -o \"QT\":\"$KEY\" | wc -l)"
	done

	for KEY in $CLIENTS; do
		if [ $KEY = "dns" ]; then
			export $KEY="$(echo "$LOGDATA" | grep -o  \"CP\":\"\" | wc -l)"
		else
			export $KEY="$(echo "$LOGDATA" | grep -o  \"CP\":\"$KEY\" | wc -l)"
		fi
	done

	avgproc=$(echo "$LOGDATA" | grep -Po '\"Elapsed\":[0-9]+' | sed "s/\"Elapsed\"://g" | awk '{ total += $0/1000000; count++ } END { print total/count }')

fi

echo "multigraph adguardhome_queries"
echo "queries.value $queries"
echo "blocked.value $blocked"
echo "safesearch.value $safesearch"
echo "safebrowsing.value $safebrowsing"
echo "parental.value $parental"
echo "multigraph adguardhome_query_types"
for KEY in $RECORDS; do
        echo "$KEY.value $(eval echo \$"$KEY")"
done
echo "multigraph adguardhome_client_protos"
for KEY in $CLIENTS; do
        echo "$KEY.value $(eval echo \$"$KEY")"
done
echo "multigraph adguardhome_avgproc"
echo "avgproc.value $avgproc"