#! /bin/sh
### BEGIN INIT INFO
# Provides:          saveoverlays
# Required-Start:    $local_fs $time
# X-Stop-After:      $time
# Required-Start:    $local_fs $time
# Required-Stop:     $local_fs
# Default-Start:     S
# Default-Stop:      0 1 6
# Short-Description: Save logs and files from overlay mounts
# Description:       Save logs and files from overlay mounts
### END INIT INFO

# Do NOT "set -e"
#
# Testing hints:
#	sudo mount -o remount,ro / 
#	sudo env INIT_VERBOSE=yes /etc/init.d/saveoverlays stop
#	cat /var/log/saveoverlays.log  

PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/bin
DESC="overlay filesystem sync"
NAME=saveoverlays

if [ -f "/etc/default/$NAME" ]; then
    . "/etc/default/$NAME"
fi
TMPLOG=/tmp/$NAME.log
LOGFILE=/var_org/log/$NAME.log

SYNCDIRS=${SYNCDIRS:-$( mount | awk '/^overlay/ { print $3 ":"  $3 "_org" }' )}
SYNCEXCLUDES=${SYNCEXCLUDES:-'--exclude .unionfs* --exclude .fuse_hidden* --exclude *.leases --exclude stats'}
SYNCFLAGS=${SYNCFLAGS:-"-avH --inplace --delete"}

# Check if we are running with read-only root
# ROROOT=$( mount | egrep '^/dev/.*on / .*ro,' )
ROROOT=$( awk '$2=="/" { print substr($4,1,2) }' /proc/mounts )
DOSYNC=${FORCESYNC:-"$ROROOT"}

# 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

#
# Function that starts the daemon/service
#
do_start()
{
	if [ "${ROROOT}" == "ro" ]
	then
		log_action_msg "Read-only root active"
	else
		log_action_msg "Read-only root inactive"
	fi
	if date '+%Y' | grep -q 1970
	then
		log_action_msg "Clock is not set. Trying fake-hwclock"
		fake-hwclock load
	fi
}

#
# Function that syncs the files
#
do_sync()
{
        RETVAL=0
        #
        # If we run with overlayfs, try to sync the dirs
        #
	if [ "${ROROOT}" != "ro" ] || mount -o remount,rw / >> ${TMPLOG} 2>&1
	then
		echo "----------------------------" >> ${TMPLOG}
		echo "$NAME sync started at `date`" >> ${TMPLOG}
		for DIR in ${SYNCDIRS}
		do
			SOURCE="${DIR%%:*}"
			DEST="${DIR##*:}"
			log_action_msg "Syncing ${SOURCE} to ${DEST} ..."
			echo "----"                                      >> ${TMPLOG}
			echo "$NAME sync ${SOURCE} to ${DEST} with options ${SYNCFLAGS} ${SYNCEXCLUDES} at `date`" >> ${TMPLOG}
			if [ -d "${SOURCE}" -a -d "${DEST}" ] 
			then
				rsync ${SYNCFLAGS} ${SYNCEXCLUDES} ${SOURCE}/ ${DEST}/ >> ${TMPLOG} 2>&1
			elif [ -f "${SOURCE}" ]
			then
				cp -vp ${SOURCE} ${DEST} >> ${TMPLOG} 2>&1
			else
				log_action_msg "Skipping this step: ${SOURCE} or ${DEST} not available"
			fi
		done
		cat ${TMPLOG} >> ${LOGFILE}
		if [ -w /etc/fake-hwclock.data ]
		then
			log_action_msg "Saving fake-hwclock"
			fake-hwclock save
		fi
		log_action_msg "Sync changes to disk"
		sync; sync; sync
		#
		# return to read-only only if that is where we started
		#
		if [ "${ROROOT}" == "ro" ]
		then
			log_action_msg "Remount root as read-only"
			mount -o remount,ro /
		fi
	else
		log_action_msg "Remounting root as writeable failed!"
		RETVAL=2
	fi
        return "$RETVAL"
}

#
# Function that stops the daemon/service
#
do_stop()
{
        #
        # If we run with overlayfs, try to sync the dirs
        #
        if [ -n "${DOSYNC}" ]
        then
		do_sync;
		return $?
	else
		log_action_msg "Root is not read-only. No action"
		return 0
        fi
}


case "$1" in
  start)
        log_daemon_msg "Starting $DESC" "$NAME"
        do_start
        case "$?" in
                0|1) log_end_msg 0 ;;
                2)   log_end_msg 1 ;;
        esac
        ;;
  stop)
        log_daemon_msg "Stopping $DESC" "$NAME"
        do_stop
        case "$?" in
                0|1) log_end_msg 0 ;;
                2)   log_end_msg 1 ;;
        esac
        ;;
  sync)
        log_daemon_msg "Syncing $DESC" "$NAME"
        do_sync
        case "$?" in
                0|1) log_end_msg 0 ;;
                2)   log_end_msg 1 ;;
        esac
        ;;
  status)
        ;;
  restart)
        ;;
  *)
        echo "Usage: $SCRIPTNAME {start|stop|status|restart}" >&2
        exit 3
        ;;
esac

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