#! /bin/sh

if [[ $# != 3 ]]; then
  echo 'Usage: sync local_dir rsync_host rsync_dir'
  exit 1
fi

set -e

TOP_DIR=/mirror
TO=$TOP_DIR/root/$1
RSYNC_HOST=$2
RSYNC_DIR=$3
LOGDIR=/var/log/mirror/$1_$2
ADDRESS=129.97.134.71

mkdir -p $LOGDIR

# LOCK_TIMEOUT is a timeout in minutes.  Defaults to 360 (6 hours).
# This program creates a lock to ensure that only one copy
# of it is mirroring any one archive at any one time.
# Locks held for longer than the timeout are broken, unless
# a running rsync process appears to be connected to $RSYNC_HOST.

LOCK_TIMEOUT=360

# There should be no need to edit anything below this point, unless there
# are problems.

#-----------------------------------------------------------------------------#

# If you are accessing a rsync server/module which is password-protected,
# uncomment the following lines (and edit the other file).

# . ftpsync.conf
# export RSYNC_PASSWORD
# RSYNC_HOST=$RSYNC_USER@$RSYNC_HOST

#-----------------------------------------------------------------------------#

# Check for some environment variables
if [ -z $TO ] || [ -z $RSYNC_HOST ] || [ -z $RSYNC_DIR ] || [ -z $LOGDIR ]; then
	echo "One of the following variables seems to be empty:"
	echo "TO, RSYNC_HOST, RSYNC_DIR or LOGDIR"
	exit 2
fi

# Note: on some non-Debian systems, hostname doesn't accept -f option.
# If that's the case on your system, make sure hostname prints the full
# hostname, and remove the -f option. If there's no hostname command,
# explicitly replace `hostname -f` with the hostname.

HOSTNAME=`hostname -f`

# The hostname must match the "Site" field written in the list of mirrors.
# If hostname doesn't returns the correct value, fill and uncomment below 
HOSTNAME=mirror.csclub.uwaterloo.ca
 
LOCK="${TO}/Archive-Update-in-Progress-${HOSTNAME}"

# The temp directory used by rsync --delay-updates is not
# world-readable remotely. It must be excluded to avoid errors. 
TMP_EXCLUDE="--exclude .~tmp~/"

# Logfile
LOGFILE=$LOGDIR/debian-mirror.log

# Get in the right directory and set the umask to be group writable
# 
cd $HOME
umask 002

# Check to see if another sync is in progress
if [ -f "$LOCK" ]; then
# Note: this requires the findutils find; for other finds, adjust as necessary
  if [ "`find $LOCK -maxdepth 1 -amin -$LOCK_TIMEOUT`" = "" ]; then
# Note: this requires the procps ps; for other ps', adjust as necessary
    if ps ax | grep '[r]'sync | grep -q $RSYNC_HOST; then
      echo "stale lock found, but a rsync is still running, aiee!"
      exit 1
    else
      echo "stale lock found (not accessed in the last $LOCK_TIMEOUT minutes), forcing update!"
      rm -f $LOCK
    fi
  else
    echo "current lock file exists, unable to start rsync!"
    exit 1
  fi
fi

touch $LOCK
# Note: on some non-Debian systems, trap doesn't accept "exit" as signal
# specification. If that's the case on your system, try using "0".
trap "rm -f $LOCK" exit

set +e

# Now sync the remaining stuff
rsync --recursive --links --hard-links --times --verbose --delay-updates --delete-after \
     --exclude "Archive-Update-in-Progress-${HOSTNAME}" \
     --address=$ADDRESS $TMP_EXCLUDE \
     $RSYNC_HOST::$RSYNC_DIR $TO >> $LOGFILE 2>&1

savelog $LOGFILE >/dev/null

rm $LOCK