#!/bin/bash

#

### BEGIN INIT INFO

# chkconfig: 2345 91 10

# processname: munin-node

# config: /etc/munin/munin-node.conf

# pidfile: /var/run/munin-asyncd.pid

# Provides: munin-asyncd

# Required-Start: $local_fs $remote_fs $network munin-node

# Required-Stop: $local_fs $remote_fs $network

# Default-Start: 2 3 4 5

# Default-Stop: 0 1 6

# Short-Description: Starts and stops munin-asyncd

# Description: munin-asyncd enables asyncronous fetching of

#              metrics from munin-node in a Munin monitoring setup.

### END INIT INFO

ASYNC_BIN=munin-asyncd

PATH=/sbin:/bin:/usr/sbin:/usr/bin

DAEMON=/usr/sbin/${ASYNC_BIN}

PIDFILE=/var/run/munin/${ASYNC_BIN}.pid

is_running () {

	if [ ! -e "$PIDFILE" ]; then

		return 3 # No PID file exists, ${ASYNC_BIN} must not be running

	else

		kill -0 $(cat $PIDFILE) 2> /dev/null

		if [ "$?" -eq "0" ]; then

			return 0 # PID file exists, and PID found in file is in use

		else

			rm $PIDFILE 2> /dev/null

			if [ "$?" -eq "0" ]; then

				return 1 # PID file exists, but no process with the PID was found. Deletion of the PID file was a success

			else

				return 2 # PID file exists, but no process with the PID was found. Deletion of the PID file failed

			fi

		fi

	fi

}

check_root () {

	operation=$1

	if [ "$(id -u)" -ne "0" ]; then

		echo "Root permissions are required in order to perform the \"$operation\" operation."

		exit 4

	fi

}

sanity_check () {

	if [ ! "$(type -p pidof)" ]; then

		echo "The program \"pidof\" is required in order for this script to work properly, and will not run without it."

		exit 1

	fi

	if [ ! -d "$(dirname $PIDFILE)" ]; then

		mkdir -p $(dirname $PIDFILE) 2> /dev/null

		if [ "$?" -ne "0" ]; then

			echo "The directory for a PID file is missing ($(dirname $PIDFILE)), and could not be created automatically. Please correct this and try again."

			exit 1

		fi

	fi

	if [ ! -x "$DAEMON" ]; then

		echo "${ASYNC_BIN} was expected at $DAEMON, but was not found. Are you sure Munin is correctly installed?"

		exit 5

	fi

}

case $1 in

	start)

		check_root $1

		sanity_check

		echo -n "Starting ${ASYNC_BIN} ... "

		is_running

		if [ "$?" -eq "0" ]; then

			echo "Already running (PID: $(cat $PIDFILE))."

			exit 0

		fi

		$DAEMON > /dev/null 2> /dev/null < /dev/null &

		sleep 0.5 # Give ${ASYNC_BIN} time to fail, if it fails

		pid=$(pidof -o %PPID -x $DAEMON)

		if [ "$?" -eq "0" ]; then

			echo $pid > $PIDFILE

			echo "Done."

			exit 0

		else

			echo "Start failed for some reason, restarting ${ASYNC_BIN} so you can see why:"

			$DAEMON

			echo

			echo "A \"Connection refused\" message typically is because munin-node is not started prior to ${ASYNC_BIN}."

		fi

	;;

	stop)

		check_root $1

		sanity_check

		echo -n "Stopping ${ASYNC_BIN} ... "

		# If a PID file is not found, we perform an extra check if ${ASYNC_BIN} still should be running, and if it does, then create a PID file

		if [ ! -e "$PIDFILE" ]; then

			pid=$(pidof -o %PPID -x $DAEMON)

			if [ "$?" -eq "0" ]; then

				echo $pid > $PIDFILE

			fi

		fi

		is_running

		if [ "$?" -ne "0" ]; then

			echo "Not running."

			exit 0

		fi

		PID=$(cat $PIDFILE)

		kill -15 $PID 2> /dev/null

		HALFSECONDS="0"

		while true; do

			kill -0 $PID 2> /dev/null

			if [ "$?" -eq "1" ]; then

				break

			fi

			sleep 0.5

			HALFSECONDS=$(expr $HALFSECONDS + 1)

			if [ "$HALFSECONDS" -ge "10" ]; then

				kill -9 $PID 2> /dev/null

				echo "Not stopping gracefully, killed!"

				exit 0

			fi

		done

		echo "Done."

		exit 0

	;;

	restart|try-restart|force-reload)

		check_root $1

		sanity_check

		$0 stop

		$0 start

		exit 0

	;;

	reload)

		echo "The \"reload\" operation is not supported by ${ASYNC_BIN}. You probably want to run \"restart\" instead."

		exit 3

	;;

	status)

		is_running

		return="$?"

		if [ "$return" -eq "0" ]; then

			echo "${ASYNC_BIN} is running (PID: $(cat $PIDFILE))."

			exit 0

		elif [ "$return" -eq "1" ]; then

			echo "${ASYNC_BIN} is not running, but PID file still existed (has been removed now)."

			exit 1

		elif [ "$return" -eq "2" ]; then

			echo "${ASYNC_BIN} is not running, but PID file still exists (could not be removed)."

			exit 1

		elif [ "$return" -eq "3" ]; then

			echo "${ASYNC_BIN} is not running."

			exit 3

		fi

		exit 4

	;;

	*)

		echo "Usage: $0 {start|stop|restart|try-restart|force-reload|reload|status}"

		exit 2

	;;

esac