#! /bin/sh
### BEGIN INIT INFO
# Provides:          xcp-xapi
# Required-Start:    $remote_fs $syslog xcp-squeezed xcp-v6d xcp-fe
# Required-Stop:     $remote_fs $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Xen API server
# Description:       The Xen API server
#                    
### END INIT INFO

# Author: Jon Ludlam <jonathan.ludlam@eu.citrix.com>
#

# Do NOT "set -e"

XAPI_INIT_COMPLETE_COOKIE=/var/run/xapi_init_complete.cookie
XAPI_STARTUP_COOKIE=/var/run/xapi_startup.cookie

# PATH should only include /usr/* if it runs after the mountnfs.sh script
PATH=/sbin:/usr/sbin:/bin:/usr/bin
DESC="The XenAPI server"
NAME=xapi
DAEMON=/usr/sbin/$NAME
DAEMON_ARGS="-daemon -writereadyfile $XAPI_STARTUP_COOKIE -writeinitcomplete $XAPI_INIT_COMPLETE_COOKIE"
PIDFILE=/var/run/$NAME.pid
SCRIPTNAME=/etc/init.d/$NAME
TEMPLATES_MD5_STAMP=/var/lib/xcp/templates.md5

# Exit if the package is not installed
[ -x "$DAEMON" ] || exit 0

# Exit if we are not in dom0
grep hypervisor /proc/cpuinfo > /dev/null || exit 0

# Read configuration variable file if it is present
[ -r /etc/default/$NAME ] && . /etc/default/$NAME

# Read xen configuration variable file if it is present
[ -r /etc/default/xen ] && . /etc/default/xen

# Load the VERBOSE setting and other rcS variables
. /lib/init/vars.sh

# Define LSB log_* functions.
# Depend on lsb-base (>= 3.2-14) to ensure that this file is present
# and status_of_proc is working.
. /lib/lsb/init-functions

# Exit cleanly if TOOLSTACK != xapi
if [ "${TOOLSTACK}" != "xapi" ]; then
	log_failure_msg "Xen toolstack is not set to xapi! Exiting."
	exit 0
fi

# Exit with failure if xend is running
if [ -f /var/run/xend.pid ]; then
       log_failure_msg "/var/run/xend.pid exists; ${NAME} conflicts with xend"
       exit 1
fi

# Wait for xapi to write its "init complete" cookie: after here it's safe to modify templates.
wait_for_xapi() {
    MAX_RETRIES=50
    RETRY=0
    while [ ${RETRY} -lt ${MAX_RETRIES} ]; do
        if [ -e ${XAPI_STARTUP_COOKIE} ]; then
            return 0
        fi
        sleep 1
        RETRY=$(( ${RETRY} + 1 ))
    done
    return 1
}

#
# Function that starts the daemon/service
#
do_start()
{
	# Return
	#   0 if daemon has been started
	#   1 if daemon was already running
	#   2 if daemon could not be started
	modprobe xen-netback
	modprobe xen-blkback
	modprobe blktap

	mkdir -p /var/run/xend/boot
	mkdir -p /usr/share/xcp/packages/iso
	export OCAMLRUNPARAM=b
	
	rm -f $XAPI_STARTUP_COOKIE $XAPI_INIT_COMPLETE_COOKIE

	start-stop-daemon --start --quiet --pidfile $PIDFILE --exec $DAEMON --test > /dev/null \
		|| return 1
	start-stop-daemon --start --quiet --pidfile $PIDFILE --exec $DAEMON -- \
		$DAEMON_ARGS \
		|| return 2
	# Add code here, if necessary, that waits for the process to be ready
	# to handle requests from services started subsequently which depend
	# on this one.  As a last resort, sleep for some time.
	wait_for_xapi 

	# Do some standard setup, e.g. pif-scan, template creation (maybe)
	. /etc/xcp/inventory
	xe pif-scan host-uuid=${INSTALLATION_UUID}

	# Check whether the md5 of the create-templates binary matches the one
	# used previously. If not, recreate the templates.
	if [ -e /usr/lib/xcp/lib/create_templates ]; then
		if ! md5sum -c --status $TEMPLATES_MD5_STAMP ; then
			/usr/lib/xcp/lib/regenerate-templates start
			md5sum /usr/lib/xcp/lib/create_templates > $TEMPLATES_MD5_STAMP
		fi
	fi
}

#
# Function that stops the daemon/service
#
do_stop()
{
	# Return
	#   0 if daemon has been stopped
	#   1 if daemon was already stopped
	#   2 if daemon could not be stopped
	#   other if a failure occurred
	start-stop-daemon --stop --quiet --retry=TERM/30/KILL/5 --pidfile $PIDFILE --name $NAME
	RETVAL="$?"
	[ "$RETVAL" = 2 ] && return 2
	# Wait for children to finish too if this is a daemon that forks
	# and if the daemon is only ever run from this initscript.
	# If the above conditions are not satisfied then add some other code
	# that waits for the process to drop all resources that could be
	# needed by services started subsequently.  A last resort is to
	# sleep for some time.
	start-stop-daemon --stop --quiet --oknodo --retry=0/30/KILL/5 --exec $DAEMON
	[ "$?" = 2 ] && return 2
	# Many daemons don't delete their pidfiles when they exit.
	rm -f $PIDFILE
	return "$RETVAL"
}

#
# Function that sends a SIGHUP to the daemon/service
#
do_reload() {
	#
	# If the daemon can reload its configuration without
	# restarting (for example, when it is sent a SIGHUP),
	# then implement that here.
	#
	start-stop-daemon --stop --signal 1 --quiet --pidfile $PIDFILE --name $NAME
	return 0
}

case "$1" in
  start)
	[ "$VERBOSE" != no ] && log_daemon_msg "Starting $DESC" "$NAME"
	do_start
	case "$?" in
		0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
		2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
	esac
	;;
  stop)
	[ "$VERBOSE" != no ] && log_daemon_msg "Stopping $DESC" "$NAME"
	do_stop
	case "$?" in
		0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
		2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
	esac
	;;
  status)
       status_of_proc "$DAEMON" "$NAME" && exit 0 || exit $?
       ;;
  #reload|force-reload)
	#
	# If do_reload() is not implemented then leave this commented out
	# and leave 'force-reload' as an alias for 'restart'.
	#
	#log_daemon_msg "Reloading $DESC" "$NAME"
	#do_reload
	#log_end_msg $?
	#;;
  restart|force-reload)
	#
	# If the "reload" option is implemented then remove the
	# 'force-reload' alias
	#
	log_daemon_msg "Restarting $DESC" "$NAME"
	do_stop
	case "$?" in
	  0|1)
		do_start
		case "$?" in
			0) log_end_msg 0 ;;
			1) log_end_msg 1 ;; # Old process is still running
			*) log_end_msg 1 ;; # Failed to start
		esac
		;;
	  *)
	  	# Failed to stop
		log_end_msg 1
		;;
	esac
	;;
  *)
	#echo "Usage: $SCRIPTNAME {start|stop|restart|reload|force-reload}" >&2
	echo "Usage: $SCRIPTNAME {start|stop|status|restart|force-reload}" >&2
	exit 3
	;;
esac

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