#!/bin/bash
#
# Plugin to monitor Bind9 Name Server Socket Stats
#
# Author:
#    Dave Fennell <dave@microtux.co.uk>
#
# Created:
#    20th December 2012
#
# Usage:
#    Place in /etc/munin/plugins/ (or link it there using ln -s)
#
# Parameters:
#    config   (required)
#

# change those to reflect your bind configuration (use plugin configuration)
# stat file
if [ "$stat_file" = "" ]; then
	stat_file="/var/cache/bind/named.stats"
fi

# rndc path
if [ "$rndc" = "" ]; then
	rndc="/usr/sbin/rndc"
fi

# Blank the stats file (else stats are appended not replaced)
rm ${stat_file}

# Ask to bind to build new one
${rndc} stats

# The section we are looking for in the stats.
section="Socket I/O Statistics"

# Get all the lines in the section:
# - cat the file
# - use sed to get lines after (and excluding) the section start tag
# - use sed to get lines up to (and excluding) the next section start tag
# - use grep to remove any lines starting with a [
cmd='cat "/var/cache/bind/named.stats" | sed "0,/^\+\+ '${section//\//\\/}' \+\+/d" | sed -e "/^\+\+/,\$d" | grep -v "^\["'

# Config mode.
if [ "$1" = "config" ]; then
	echo 'graph_args --lower-limit 0'
	echo 'graph_category dns'
	echo 'graph_info '${section}' for the Bind9 Name Server'
	echo 'graph_scale no'
	echo 'graph_title Bind9 '${section}
	echo 'graph_vlabel requests/sec'

	# Output the stat configs.
	eval ${cmd} | while read num name
	do
		label=${name}

		# All lowercase.
		key=$(echo "$name" | tr 'A-Z' 'a-z')

		# Now change names to all have no spaces.
		key=${key//[\/ - ]/_}

		echo ${key}.label ${label}
		echo ${key}.info ${name}
		echo ${key}.type COUNTER
	done

	exit 0
fi

# Blank the stats file (else stats are appended not replaced)
rm ${stat_file}

# Ask to bind to build new one
${rndc} stats

# Output the stats.
eval ${cmd} | while read num name
do
	# All lowercase.
	key=$(echo "$name" | tr 'A-Z' 'a-z')

	# Now change names to all have no spaces.
	key=${key//[\/ - ]/_}

	echo ${key}.value ${num}
done