Munin contributed plugins

#!/bin/bash

# Plugin to monitor traffic rate to specific host.

#

# Requirements:

#	- tcpdump

#	- should be run as root or any other user for tcpdump

#

# Parameters supported:

#	config

#	autoconf

#

# Configurable variables

#

#	type       - monitor type. Available values: packets, bytes. Defaults to packets because it's faster

#	hostname   - mandatory. Hostname (ip) to monitor connections to. Actually just a part of tcpdump expr.

#                    Thus a hack: '1.2.3.4 and port 80' will monitor port 80 only. Bingo!

#	interface  - self-explanatory

#

# IMPORTANT! This plugin spawns 'tcpdump' process along with bash shell piping tcpdump output there

# PLEASE DO NOT FORGET TO KILL when removing plugin/stopping/etc. You can kill any of three, the others should die

#

# Revision 0.1  2011/08/06 Artem Sheremet

# Revision 0.2  2011/10/23 -

INTERVAL=300

if [ -z "$type" ]; then

        type=packets

fi

if [ -z "$hostname" ]; then

        echo "Configuration problem" >&2

        exit 1

fi

if [ "$interface" ]; then

	interface="-i $interface"

fi

TCPDUMP="tcpdump $interface -nqt host $hostname"

if [ "$1" = "config" ]; then

        echo "graph_title Number of $type for host $hostname"

        if [ "$type" == "bytes" ]; then

                echo "graph_args --base 1024"

        fi

        echo "graph_category network"

        echo "graph_vlabel $type per second"

        echo "graph_info This plugin shows number of $type within host $hostname through the tcp protocol using tcpdump"

        echo "rate.label $type within $hostname"

        exit 0

fi

TMP_DIR="/tmp/host_traffic_${hostname}_${type}"

if [ ! -d "$TMP_DIR" ]; then

	mkdir -p "$TMP_DIR"

fi

if [ -f "$TMP_DIR/pid" ]; then

	PID=`cat "$TMP_DIR/pid"`

	if [ -z "$PID" -o ! -d /proc/$PID ]; then

		unset PID

	fi

fi

if [ "$PID" ]; then

	rm -f "$TMP_DIR/value"

	# IPC: call data print & reset

	kill -USR1 $PID

	# wait 10 sec for data to arrive

	for i in {1..10}; do

		if [ -r "$TMP_DIR/value" ]; then

			VALUE=`cat "$TMP_DIR/value"`

			echo $VALUE $INTERVAL | awk '{ printf("rate.value %.3f\n", $1/$2) }'

			exit 0

		fi

		sleep 1

	done

	echo "rate.value U"

else

	$TCPDUMP 2>/dev/null | (

		COUNTER=0

		# IPC: install SIGUSR1 handler

		trap 'echo $COUNTER > "$TMP_DIR/value"; COUNTER=0' SIGUSR1

		echo $BASHPID >"$TMP_DIR/pid"

		while read line; do

			if [[ "$type" == "bytes" ]]; then

				# get the last field separated by space

				COUNTER=$(($COUNTER+${line/* /})) 2>/dev/null

			else

				COUNTER=$(($COUNTER+1))

			fi

		done

	) 2>/dev/null &

fi