duplicity-backup

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.

Contributing

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

Pull requests are welcome! However please always use individual feature branches for each pull request. I will not accept any pull request from master branches.

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

The original version of the code is available 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. You SHOULD NOT edit the example config file duplicity-backup.conf.example, but instead make a copy of it (typical examples are duplicity-backup.conf in the same directory as the script or /etc/duplicity-backup.conf) 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 use Amazon S3 and have s3cmd installed).

Be sure to make the script executable (chmod +x) before you hit the gas.

Requirements

• duplicity
• Basic utilities like: which and tee (should already be available on most Linux systems)
• gpg optional
• 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 beginning of the script (default: duplicity-backup.conf in the script's directory).

So be sure to either:

• specify the configuration file path on the command line [recommended]
• or to edit the CONFIG parameter in the script 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

    -t, --time TIME            specify the time from which to restore or list 
                               files (duplicity time format)
        --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

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

Cron Usage Example

41 3 * * * cd /path/to/duplicity-backup; ./duplicity-backup.sh -c /etc/duplicity-backup.conf -b

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.

Wish List

• send mails only on failure
• support for include/exclude filelists

Thanks to all the contributors for their help.