#!/bin/bash -p
# vim:textwidth=80:tabstop=4:shiftwidth=4:smartindent:autoindent

APP=$1
shift

APPARGS="$*"				# Grab any args passed to safe_sangoma
TTY=						# TTY (if you want one) for APP to run on
CONSOLE=no					# Whether or not you want a console
#NOTIFY=user@email.com		# Who to notify about crashes
#EXEC=/path/to/somescript	# Run this command if Asterisk crashes
MACHINE=`hostname`			# To specify which machine has crashed when getting the mail
DUMPDROP=/tmp
SLEEPSECS=2
BINDIR=/usr/sbin
PIDFILE=/var/run/$APP.pid
CORENAME=$(cat /proc/sys/kernel/core_pattern)

if [ -z $APP ]; then
		echo
        echo "Error: APP argument not specified"
		echo 
		echo "Usage: safe_sangoma <app_name> <app arguments>"
		echo
        exit 1
fi

if [ ! -e $BINDIR/$APP ]; then
		echo
        echo "Error: APP not found: $BINDIR/$APP"
        exit 1
fi

# run APP with this priority
PRIORITY=0

# set system filemax on supported OSes if this variable is set
# SYSMAXFILES=262144

# set max files open with ulimit. On linux systems, this will be automatically
# set to the system's maximum files open devided by two, if not set here.
MAXFILES=32768

# Check if APP is already running.  If it is, then bug out, because
# starting safe_sangoma when APP is running is very bad.
PID=`pidof $APP`
if [ ! -z $PID ]; then
	echo "Error: $APP already running.  $0 will exit now."
	exit 1
fi

if [ -f $PIDFILE ]; then
	echo "Error: $APP pid file $PIDFILE exists!.  $0 will exit now."
	exit 1
fi

# since we're going to change priority and open files limits, we need to be
# root. if running APP as other users, pass that to APP on the command
# line.
# if we're not root, fall back to standard everything.
if [ `id -u` != 0 ]
then
	echo "Oops. I'm not root. Falling back to standard prio and file max." >&2
	echo "This is NOT suitable for large systems." >&2
	PRIORITY=0
else
	if `echo $OSTYPE | grep linux 2>&1 > /dev/null `
	then
		# maximum number of open files is set to the system maximum divided by two if
		# MAXFILES is not set.
		if [ "$MAXFILES" = "" ]
		then
			# just check if file-max is readable
			if [ -r /proc/sys/fs/file-max ]
			then
				MAXFILES=$(( `cat /proc/sys/fs/file-max` / 2 ))
			fi
		fi
		SYSCTL_MAXFILES="fs.file-max"
	elif `echo $OSTYPE | grep darwin 2>&1 > /dev/null `
	then
		SYSCTL_MAXFILES="kern.maxfiles"
	fi


	if [ "$SYSMAXFILES" != "" ]
	then
		if [ "$SYSCTL_MAXFILES" != "" ]
		then
			sysctl -w $SYSCTL_MAXFILES=$SYSMAXFILES
		fi
	fi


	# set the process's filemax to whatever set above
	ulimit -n $MAXFILES

fi

#
# Let us dump core
#
ulimit -c unlimited

#
# Don't fork when running "safely"
#

#SARGS=""
#if [ "$TTY" != "" ]; then
#	if [ -c /dev/tty${TTY} ]; then
#		TTY=tty${TTY}
#	elif [ -c /dev/vc/${TTY} ]; then
#		TTY=vc/${TTY}
#	else
#		echo "Cannot find your TTY (${TTY})" >&2
#		exit 1
#	fi
#	SARGS="${SARGS} -vvvg"
#	if [ "$CONSOLE" != "no" ]; then
#		SARGS="${SARGS} -c"
#	fi
#fi

if [ ! -w ${DUMPDROP} ]; then	
	echo "Cannot write to ${DUMPDROP}" >&2
	exit 1
fi

#
# Don't die if stdout/stderr can't be written to
#
trap '' PIPE

#
# Run scripts to set any environment variables or do any other system-specific setup needed
#

if [ -d /etc/wanpipe/safe_startup.d ]; then
	for script in /etc/wanpipe/safe_startup.d/*.sh; do
		if [ -x ${script} ]; then
			source ${script}
		fi
	done
fi

run_sangoma()
{
	while :; do 

		cd /tmp
		nice -n $PRIORITY ${BINDIR}/$APP ${APPARGS} 

		EXITSTATUS=$?
		echo "$APP ended with exit status $EXITSTATUS"
		if [ "$EXITSTATUS" = "0" ]; then
			# Properly shutdown....
			echo "$APP shutdown normally."
			exit 0
		elif [ $EXITSTATUS -gt 128 ]; then
			let EXITSIGNAL=EXITSTATUS-128
			echo "$APP exited on signal $EXITSIGNAL."
		else
			echo "$APP died with code $EXITSTATUS."
		fi

		if [ "$NOTIFY" != "" ]; then
			echo "$APP on $MACHINE exited on signal $EXITSIGNAL. Might want to take a peek." | \
			mail -s "$APP Died" $NOTIFY
		fi
		if [ "$EXEC" != "" ]; then
			$EXEC
		fi

		PID=`cat ${PIDFILE}`
		if [ -f /tmp/$CORENAME.${PID} ]; then
			mv /tmp/$CORENAME.${PID} ${DUMPDROP}/core.$APP.`hostname`-`date -Iseconds` &
		elif [ -f /tmp/$CORENAME ]; then
			mv /tmp/$CORENAME ${DUMPDROP}/core.$APP.`hostname`-`date -Iseconds` &
		fi

		echo "Automatically restarting $APP."
		sleep $SLEEPSECS
		\rm -f ${PIDFILE}
	done
}

run_sangoma &

exit 0
