ABOUT THIS SCRIPT
=================

This bash script was designed to automate and simplify the remote backup process
of duplicity on Amazon S3 primarily. Other backup destinations are possible
(FTP, SFTP, SCP, rsync, file...), i.e. any of duplicity's supported outputs.

After your script is configured, you can easily backup, restore, verify and
clean (either via cron or manually) your data without having to remember lots of
different command options and passphrases.

Most importantly, you can easily backup the script and your gpg key in a
convenient passphrase-encrypted file. This comes in in handy if/when your
machine ever does go belly up.

Optionally, you can set up an email address where the log file will be sent,
which is useful when the script is used via cron.

This version is a rewriting of the code originally written by Damon Timm,
including many patches that have been brought to the original scripts by various
forks on Github.

Latest version of the code available at:
http://github.com/zertrin/duplicity-backup

Merge requests are welcome :)

More information about this script available at:
http://zertrin.org/projects/duplicity-backup/

The original version of the code is availabe at:
http://github.com/theterran/dt-s3-backup

BEFORE YOU START
================

This script requires user configuration. Instructions are in the config file
itself and should be self-explanatory. Please DO NOT edit the example config
file, but make a copy of it and edit this one. Be sure to replace all the
*foobar* values with your real ones. Almost every value needs to be configured
in someway.

You can use one copy of the script with different settings for different backup
scenarios. It is designed to run as a cron job and will log information to a
text file (including remote file sizes, if you have s3cmd installed). Be sure to
make the script executable (chmod +x) before you hit the gas.

REQUIREMENTS
============

* duplicity
* gpg
* Amazon S3 (optional)
* s3cmd (optional)
* mailx (optional)

CONFIGURATION
=============

The configuration takes place in a separate config file and is documented there.

You want to copy duplicity-backup.conf.example to another place that suits your
needs (for example /etc/duplicity-backup.conf)

The script looks for its configuration by reading the config file specified by
the command line option -c or --config (see USAGE)

If no config file was given on the command line, the script will try to find the
file specified in the CONFIG parameter at the beggining of the script (defaults
to "duplicity-backup.conf" in the script's directory).

So be sure either:
- to specify the configuration file path on the command line [recommended]
- or to edit the CONFIG parameter in thescript to match the actual location of
  your config file. [deprecated]

NOTE: to ease future updates of the script, you may prefer NOT to edit the
      script at all and to specify systematically the path to your config file
      on the command line with the -c or --config option.

USAGE
=====

  duplicity-backup.sh [options]

  Options:
    -c, --config CONFIG_FILE   specify the config file to use

    -b, --backup               runs an incremental backup
    -f, --full                 forces a full backup

    -v, --verify               verifies the backup
        --restore [PATH]       restores the entire backup to [path]
        --restore-file [FILE_TO_RESTORE] [DESTINATION]
                               restore a specific file

    -l, --list-current-files   lists the files currently backed up in the archive
    -s, --collection-status    show all the backup sets in the archive

        --backup-script        automatically backup the script and secret key to
                               the current working directory
    -n, --dry-run              perform a trial run with no changes made

COMMON USAGE EXAMPLES
=====================

* View help:
    $ duplicity-backup.sh

* Run an incremental backup:
    $ duplicity-backup.sh [-c config_file] --backup

* Force a one-off full backup:
    $ duplicity-backup.sh [-c config_file] --full

* Restore your entire backup:
    $ duplicity-backup.sh [-c config_file] --restore
    You will be prompted for a restore directory

    $ duplicity-backup.sh [-c config_file] --restore /home/user/restore-folder
    You can also provide a restore folder on the command line.

* Restore a specific file in the backup:
    $ duplicity-backup.sh [-c config_file] --restore-file
    You will be prompted for a file to restore to the current directory

    $ duplicity-backup.sh [-c config_file] --restore-file img/mom.jpg
    Restores the file img/mom.jpg to the current directory

    $ duplicity-backup.sh [-c config_file] --restore-file img/mom.jpg /home/user/i-love-mom.jpg
    Restores the file img/mom.jpg to /home/user/i-love-mom.jpg

* List files in the remote archive
    $ duplicity-backup.sh [-c config_file] --list-current-files

* Verify the backup
    $ duplicity-backup.sh [-c config_file] --verify

* Backup the script and gpg key (for safekeeping)
    $ duplicity-backup.sh [-c config_file] --backup-script

TROUBLESHOOTING
===============

This script attempts to simplify the task of running a duplicity command; if you
are having any problems with the script the first step is to determine if the
script is generating an incorrect command or if duplicity itself is causing your
error.

To see exactly what is happening when you run duplicity-backup, either pass the
option -n or --dry-run on the command line, or head to the bottom of the
configuration file and uncomment the `ECHO=$(which echo)` variable. 

This will stop the script from running and will, instead, output the generated
command into your log file. You can then check to see if what is being generated
is causing an error or if it is duplicity causing you woe.

NEXT VERSION WISH LIST
======================

* --restore-dir option
* restore files from a specific time period
* support multiple MTAs for the email alert feature

Thanks to Mario Santagiuliana and Razvan for their help.