#
# backupninja handler to do incremental backups using
# rsync and hardlinks, based on
#
#   http://www.mikerubel.org/computers/rsync_snapshots/
#
# feedback: rhatto at riseup.net | gpl
# lot of enhancements grabbed from "rsnap" handler by paulv at bikkel.org
#
# Config file options
# -------------------
#
#   [general]
#   log = rsync log file
#   partition = partition where the backup lives
#   fscheck = set to 1 if fsck should run on $partition after the backup is made
#   read_only = set to 1 if $partition is mounted read-only
#   mountpoint = backup partition mountpoint or backup main folder
#   backupdir = folder relative do $mountpoint where the backup should be stored
#   days = number of backup increments (min = 5)
#   lockfile = lockfile to be kept during backup execution
#   nicelevel = rsync command nice level
#   enable_mv_timestamp_bug = set to "yes" if your system isnt handling timestamps correctly
#   tmp = temp folder
#
#   [source]
#   from = local or remote
#   host = source hostname or ip, if remote backup
#   testconnect = when "yes", test the connection for a remote source before backup
#   include = include folder on backup
#   exclude = exclude folder on backup
#   ssh = ssh command line (remote only)
#   rsync = rsync program
#   rsync_options = rsync command options
#   exclude_vserver = vserver-name (valid only if vservers = yes on backupninja.conf)
#   numericids = when set to 1, use numeric ids instead of user/group mappings on rsync
#   compress = if set to 1, compress data on rsync (remote source only)
#   bandwidthlimit = set a badnwidth limit in kbps (remote source only)
#   remote_rsync = remote rsync program (remote source only)
#
#   [services]
#   initscripts = absolute path where scripts are located
#   service = script name to be stoped at the begining of the backup and started at its end
#
# You can also specify some system comands if you don't want the default system values:
#
#   [system]
#   rm = rm command
#   cp = cp command
#   touch = touch command
#   mv = mv command
#   fsck = fsck command
#
# You dont need to manually specify vservers using "include = /vservers".
# They are automatically backuped if vserver is set to "yes" on you backupninja.conf.
#

# config file evaluation

setsection system
getconf rm rm
getconf cp cp
getconf touch touch
getconf mv mv
getconf fsck fsck

setsection general
getconf log /var/log/backup/rsync.log
getconf partition
getconf fscheck
getconf read_only
getconf mountpoint
getconf backupdir
getconf rotate
getconf days
getconf lockfile
getconf nicelevel 0
getconf enable_mv_timestamp_bug no
getconf tmp /tmp

setsection source
getconf from local
getconf testconnect no
getconf rsync $RSYNC
getconf rsync_options "-av --delete"
getconf ssh ssh
getconf user
getconf host
getconf include
getconf exclude
getconf exclude_vserver
getconf numericids 0
getconf compress 0
getconf bandwidthlimit
getconf remote_rsync rsync

setsection services
getconf initscripts
getconf service

# function definitions

function rotate {

  if [[ "$2" < 4 ]]; then
    error "Rotate: minimum of 4 rotations"
    exit 1
  fi

  if [ -d $1.$2 ]; then
    $nice $mv /$1.$2 /$1.tmp
  fi

  for ((n=`echo "$2 - 1" | bc`; n >= 0; n--)); do
    if [ -d $1.$n ]; then
      dest=`echo "$n + 1" | bc`
      $nice $mv /$1.$n /$1.$dest
      $touch /$1.$dest
    fi
  done

  if [ -d $1.tmp ]; then
    $nice $mv /$1.tmp /$1.0
  fi

  if [ -d $1.1 ]; then
    $nice $cp -alf /$1.1/. /$1.0
  fi

}

function move_files {

 ref=$tmp/makesnapshot-mymv-$$;
 $touch -r $1 $ref;
 $mv $1 $2;
 $touch -r $ref $2;
 $rm $ref;

}

backupdir="$mountpoint/$backupdir"

# does $backupdir exists?

if [ ! -d "$backupdir" ]; then 
  error "Backupdir $backupdir does not exist"
  exit 1
fi

# setup number of increments

if [ -z "$days" ]; then
  keep="4"
else
  keep="`echo $days - 1 | bc -l`"
fi

# lockfile setup

if [ ! -z "$lockfile" ]; then
  $touch $lockfile || warning "Could not create lockfile $lockfile"
fi

# nicelevel setup

if [ ! -z "$nicelevel" ]; then 
  nice="nice -n $nicelevel"
else 
  nice=""
fi

# connection test

if [ "$from" == "remote" ] && [ "$testconnect" == "yes" ]; then
  debug "$ssh -o PasswordAuthentication=no $user@$host 'echo -n 1'"
  result=`ssh -o PasswordAuthentication=no $user@$host 'echo -n 1'`
  if [ "$result" != "1" ]; then
    fatal "Can't connect to $host as $user."
  else
    debug "Connected to $srchost successfully"
  fi
fi

# rsync options for local sources

if [ "$from" == "local" ]; then

  rsync_local_options="$rsync_options"

  if [ ! -z "$numericids" ]; then
    rsync_local_options="$rsync_local_options --numeric-ids "
  fi

fi

# rsync options for remote sources

if [ "$from" == "remote" ]; then

  rsync_remote_options="$rsync_options --rsync-path=$remote_rsync"

  if [ "$compress" == "1" ]; then
    rsync_remote_options="$rsync_remote_options --compress"
  fi

  if [ ! -z "$bandwidthlimit" ]; then
    rsync_remote_options="$rsync_remote_options --bwlimit=$bandwidthlimit"
  fi

  if [ ! -z "$numericids" ]; then
    rsync_remote_options="$rsync_remote_options --numeric-ids"
  fi

fi

# set mv procedure

if [ $enable_mv_timestamp_bug == "yes" ]; then
  mv=move_files
fi

# set excludes

for path in $exclude; do
  EXCLUDES="$EXCLUDES --exclude=$path"
done

# stop services

if [ ! -z "$service" ]; then
  for daemon in $service; do
    info "Stopping service $daemon..."
    $initscripts/$daemon stop
  done
fi

echo "Starting backup at `date`" >> $log

# mount backup destination folder as read-write

if [ "$read_only" == "1" ] || [ "$read_only" == "yes" ]; then
  if [ -d "$mountpoint" ]; then
    mount -o remount,rw $mountpoint
    if (($?)); then
      error "Could not mount $mountpoint"
      exit 1
    fi
  fi
fi

# add vservers to included folders

if [ "$vservers_are_available" == "yes" ]; then

  # sane permission on backup
  mkdir -p $backupdir/$VROOTDIR
  chmod 000 $backupdir/$VROOTDIR

  for candidate in $found_vservers; do
    candidate="`basename $candidate`"
    found_excluded_vserver="0"
    for excluded_vserver in $exclude_vserver; do
      if [ "$excluded_vserver" == "$candidate" ]; then
        found_excluded_vserver="1"
        break
      fi
    done
    if [ "$found_excluded_vserver" == "0" ]; then
      include="$include $VROOTDIR/$candidate"
    fi
  done
fi

# the backup procedure

for SECTION in $include; do

  section="`basename $SECTION`"

  if [ ! -d "$backupdir/$SECTION/$section.0" ]; then
    mkdir -p $backupdir/$SECTION/$section.0
  fi
 
  info "Rotating $backupdir/$SECTION/$section..."
  echo "Rotating $backupdir/$SECTION/$section..." >> $log
  rotate $backupdir/$SECTION/$section $keep
  info "Syncing $SECTION on $backupdir/$SECTION/$section.0..."

  if [ "$from" == "local" ]; then
    debug $rsync $rsync_local_options $EXCLUDES /$SECTION/ $backupdir/$SECTION/$section.0/ 
    $nice $rsync $rsync_local_options $EXCLUDES /$SECTION/ $backupdir/$SECTION/$section.0/ >> $log
    if [ "$?" != "0" ]; then
      warning "Rsync error when trying to transfer $SECTION"
    fi
  elif [ "$from" == "remote" ]; then
    if [ -z "$user" ] || [ -z "$host" ]; then
      error "Config file error: either user or host was not specified"
      exit 1
    else
      debug $nice $rsync $rsync_remote_options $EXCLUDES -e "$ssh" $user@$host:/$SECTION/ $backupdir/$SECTION/$section.0
      $nice $rsync $rsync_remote_options $EXCLUDES -e "$ssh" $user@$host:/$SECTION/ $backupdir/$SECTION/$section.0 >> $log
      if [ "$?" != "0" ]; then
        warning "Rsync error when trying to transfer $SECTION"
      fi
    fi
  else
    error "Invalid source $from"
    exit 1
  fi

  $touch $backupdir/$SECTION/$section.0

done

# remount backup destination as read-only

if [ "$read_only" == "1" ] || [ "$read_only" == "yes" ]; then
  mount -o remount,ro $mountpoint
fi

# check partition for errors

if [ "$fscheck" == "1" ] || [ "$fscheck" == "yes" ]; then
  umount $mountpoint
  if (($?)); then
    warning "Could not umount $mountpoint to run fsck"
  else
    $nice $fsck -v -y $partition >> $log
    mount $mountpoint
  fi
fi

# restart services

if [ ! -z "$service" ]; then
  for daemon in $service; do
    info "Starting service $daemon..."
    $initscripts/$daemon start
  done
fi

# removes the lockfile

if [ ! -z "$lockfile" ]; then
  $rm $lockfile || warning "Could not remove lockfile $lockfile"
fi

echo "Finnishing backup at `date`" >> $log