= S3QL Backup Script =

Following is a modified version of the [http://www.rath.org/s3ql-docs/contrib.html#s3-backup-sh s3_backup.sh] script which which was provided by the Debian package at `/usr/share/doc/s3ql/examples/s3ql_backup.sh`.

It expects a `/etc/s3ql/SERVERNAME` file listing directories to be backed up for each server and the SERVERNAME is expected to match the bucket name.

{{{
#!/bin/bash

# Abort entire script if any command fails
set -e

# This script assumes that bucketname and directory under 
# /media match and is also assumes that a file, with the 
# same name with a list of directories to backup exists 
# in /etc/s3ql

# Check for bucket name / directory on standard input
if [[ $1 ]]; then
  BUCKET=$1
elif [[ ! $1 ]]; then
  echo "Type the bucketname and then [ENTER]:"
  read bucket
  BUCKET=$bucket
fi

# Backup destination  (storage url)
storage_url="s3c://s.qstack.advania.com:443/$BUCKET"

# Check that a list of diectories to backup exists at 
# /etc/s3ql/$BUCKET
if [[ ! -f "/etc/s3ql/$BUCKET" ]]; then
  echo "You need to create /etc/s3ql/$BUCKET with a list of directories to backup"
  exit
else
  BACKUP_LIST="/etc/s3ql/$BUCKET"
fi

# Recover cache if e.g. system was shut down while fs was mounted
fsck.s3ql --backend-options="dumb-copy" --batch "$storage_url"

# Create a temporary mountpoint and mount file system
mountpoint="/tmp/s3ql_backup_$$"
mkdir "$mountpoint"
mount.s3ql --backend-options="dumb-copy" "$storage_url" "$mountpoint"

# Make sure the file system is unmounted when we are done
# Note that this overwrites the earlier trap, so we
# also delete the lock file here.
trap "cd /; umount.s3ql '$mountpoint'; rmdir '$mountpoint'; rm '$lock'" EXIT

# Figure out the most recent backup
cd "$mountpoint"
last_backup=`python <<EOF
import os
import re
backups=sorted(x for x in os.listdir('.') if re.match(r'^[\\d-]{10}_[\\d:]{8}$', x))
if backups:
    print backups[-1]
EOF`

# Duplicate the most recent backup unless this is the first backup
new_backup=`date "+%Y-%m-%d_%H:%M:%S"`
if [ -n "$last_backup" ]; then
    echo "Copying $last_backup to $new_backup..."
    s3qlcp "$last_backup" "$new_backup"

    # Make the last backup immutable
    # (in case the previous backup was interrupted prematurely)
    s3qllock "$last_backup"
fi

# ..and update the copy
#rsync -aHAXx --delete-during --delete-excluded --partial -v \
#    --exclude /.cache/ \
#    --exclude /.s3ql/ \
#    --exclude /.thumbnails/ \
#    --exclude /tmp/ \
#    "/home/my_username/" "./$new_backup/"

if [[ -d $mountpoint ]]; then
  if [[ ! -d "$mountpoint/$new_backup" ]]; then
    echo "$mountpoint/$new_backup doesn't exist so creating it"
    mkdir -p $mountpoint/$new_backup
  fi
  for dir in $(<${BACKUP_LIST}); do
    mkdir -p "$mountpoint/$new_backup$dir/"
    rsync -aHAXx --delete-during --delete-excluded --partial -v "/media/$BUCKET$dir/" "$mountpoint/$new_backup$dir/"
  done
else
  echo "$mountpoint doesn't exist - something has gone horribly wrong"
  exit
fi

# Make the new backup immutable
s3qllock "$new_backup"

# Expire old backups

# Note that expire_backups.py comes from contrib/ and is not installed
# by default when you install from the source tarball. If you have
# installed an S3QL package for your distribution, this script *may*
# be installed, and it *may* also not have the .py ending.
expire_backups --use-s3qlrm 1 7 14 31 90 180 360
}}}