#!/bin/bash
#
# Script to launch apache repeatedly via httpd -X
#
# The script guesses the desired apache config and handles
# - sudo
# - pidfile
# - semaphore cleanup
#

# -----------------------------------------------------------------------
# FUNCTIONS
# -----------------------------------------------------------------------

function usage() {

echo
echo "$0"

cat <<'EOF'

Script to launch apache repeatedly via httpd -X.

The script guesses the desired apache config and handles
 - sudo
 - pidfile
 - semaphore cleanup

EOF

}

function wait_pid_exists() {
	N=0
	while [ $N -lt 40 ]; do
		sleep 0.1
		if [ -f $AP_PID_FILE ]; then
			echo "ok"
			break
		fi
		N=$((N+1)) 
	done
	if [ $N -ge 40 ]; then
		echo "fail ($AP_PID_FILE)"
		pwd
	fi
}

function wait_process_disappears() {
	N=0
	while [ $N -lt 40 ]; do
		sleep 0.1
		if [ ! -f $AP_PID_FILE ]; then
			echo "ok"
			break
		fi
		if [ -f $AP_PID_FILE ]; then
			ps ax | grep -v " grep " | grep -q $(cat $AP_PID_FILE) 
			if [ $? -eq 1 ]; then
				sudo rm $AP_PID_FILE
				echo "ok"
				break
			fi
		fi
		N=$((N+1)) 
	done
	if [ $N -ge 40 ]; then
		echo "fail"
	fi
}


# -----------------------------------------------------------------------
# INIT
# -----------------------------------------------------------------------

VERBOSE=0

AP_CONFS_PATTERN="/etc/apache2/apache2.conf /apache/conf/httpd.conf_* /opt/apache*/conf/httpd.conf_*"
AP_CONF_FILE=$(ls -tr $AP_CONFS_PATTERN 2>/dev/null | tail -1)

if [ ! -f $AP_CONF_FILE ]; then
	echo "Apache config file can not be determined. This is fatal. Aborting."
	exit 1
fi

AP_ROOT=$(grep ServerRoot $AP_CONF_FILE | sed -e "s/.*ServerRoot\s*//" | tr -d "'" | tr -d '"')
if [ ! -d $AP_ROOT ]; then
	if [ -d "/usr/local/apache" ]; then
		AP_ROOT="/usr/local/apache"
	else
		echo "Apache server root can not be determined. This is fatal. Aborting."
		exit 1
	fi
fi
		
AP_BIN="$AP_ROOT/bin/httpd"

if [ ! -f $AP_BIN ]; then
	if [ -f "/usr/sbin/apache2" ]; then
		AP_BIN="/usr/sbin/apache2"
	else
		echo "Apache binary can not be determined. This is fatal. Aborting."
		exit 1
	fi
fi

AP_PID_FILE=$(grep PidFile $AP_CONF_FILE | sed -e "s/.*PidFile\s*//" | tr -d "'" | tr -d '"')

echo "$AP_PID_FILE" | egrep -q "^\/"
if [ $? -eq 1 ]; then
	AP_PID_FILE="$AP_ROOT/$AP_PID_FILE"
fi

if [ -z "AP_PID_FILE" -o "$AP_PID_FILE" == "" ]; then
	AP_PID_FILE="$AP_ROOT/logs/httpd.pid"
fi


AP_USER=$(egrep "\bUser\s+" $AP_CONF_FILE | sed -e "s/.*User\s*//" | tr -d "'" | tr -d '"')

if [ -z "AP_USER" -o "$AP_USER" == "${APACHE_RUN_USER}" ]; then
	AP_USER="www-data"
fi

# param checking loop
while [ 1 ]
do
        if [ -n "$1" ]; then
                ARG="$1"
                export FC="`echo $ARG | sed -e 's/^\(.\).*/\1/'`"   # first char of $ARG
                if [ "-" = $FC ]; then
                        case $1 in
                        -h) usage; exit;;
                        --help) usage; exit;;
                        -v) export VERBOSE=1;;
                        --verbose) export VERBOSE=1;;
                        esac
                        shift
                else
                        break
                fi
        else
                break
        fi
done

if [ "$VERBOSE" -eq 1 ]; then
	echo "Apache Root:    $AP_ROOT"
	echo "Apache Binary:  $AP_BIN"
	echo "Apache Config:  $AP_CONF_FILE"
	echo "Apache PidFile: $AP_PID_FILE"
	echo "Apache User:    $AP_USER"
fi


# -----------------------------------------------------------------------
# MAIN LOOP
# -----------------------------------------------------------------------

while [ 1 ]; do
	echo
	if [ -f $AP_PID_FILE ]; then
		
		ps ax | grep -v " grep " | grep -q $(cat $AP_PID_FILE) 
		
		if [ $? -eq 0 ]; then

			echo -n "Stopping active apache process ... "

			sudo kill -TERM $(cat $AP_PID_FILE)

			wait_process_disappears
		else
			sudo rm $AP_PID_FILE
		fi
	fi

	# clean up semaphores
	sudo ipcs -s | grep $AP_USER | awk '{ print $2 }' | xargs -n 1 sudo ipcrm sem 2>/dev/null >/dev/null

	echo -n "Launching apache on config file $AP_CONF_FILE ... "

	sudo $AP_BIN -X -f $AP_CONF_FILE &

	wait_pid_exists
	
	echo
	read -r -p 'Press [enter] to restart apache, enter [q] to stop apache and exit: ' var

	if [ "$var" == "q" ]; then
		break

	fi
done


# -----------------------------------------------------------------------
# SHUT-DOWN
# -----------------------------------------------------------------------

echo
echo -n "Bailing out ... "

if [ -f $AP_PID_FILE ]; then
	sudo kill -TERM $(cat $AP_PID_FILE)
	wait_process_disappears
fi

echo