duplicity-backup.sh

This bash script was designed to automate and simplify the remote backup process of duplicity on Amazon S3 primarily. Other backup destinations are possible (Google Cloud Storage, 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. Thanks to all the contributors!

duplicity-backup.sh IS NOT duplicity

It is only a wrapper script for duplicity written in bash!

This means the following:

• You need to install and configure duplicity BEFORE using duplicity-backup.sh
• The official documentation of duplicity is relevant to duplicity-backup.sh too. Virtually any option supported by duplicity can be specified in the config file of duplicity-backup.sh. See the STATIC_OPTIONS, CLEAN_UP_TYPE and CLEAN_UP_VARIABLE parameters in particular.
• Before asking something about duplicity-backup.sh, ensure that your question isn’t actually concerning duplicity ;) First, make sure you can perform a backup with duplicity without using this script. If you can't make the backup work with duplicity alone, the problem is probably concerning duplicity and not this script. If you manage to make a backup with duplicity alone but not with this script, then there is probably a problem with duplicity-backup.sh.
• In particular, to the question "Does duplicity-backup.sh support the backend XXX" (with XXX being for example Amazon Glacier), the answer is always the same: "duplicity-backup.sh uses duplicity, so ask the developers of duplicity ;) Once it's in duplicity, it's automatically available to duplicity-backup.sh"

Contributing

Latest version of the code is available at https://github.com/zertrin/duplicity-backup in the master branch.

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

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

The original version of the code is available at https://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 if needed (chmod +x) before you hit the gas.

Requirements

• duplicity
• Basic utilities like: bash, which, find and tee (should already be available on most Linux systems)
• gpg optional (if using encryption)
• mailx optional (if sending mail is activated in the script)

For the Amazon S3 storage backend optional

• s3cmd optional

For the Google Cloud Storage storage backend optional

• boto (may already have been installed with duplicity)
• gsutil optional

Configuration

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

You should 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 with the -c option [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
    -l, --list-current-files   lists the files currently backed up in the archive
    -s, --collection-status    show all the backup sets in the archive

        --restore [PATH]       restores the entire backup to [path]
        --restore-file [FILE_TO_RESTORE] [DESTINATION]
                               restore a specific file
        --restore-dir [DIR_TO_RESTORE] [DESTINATION]
                               restore a specific directory

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

    --backup-script            automatically backup the script and secret key(s) to
                               the current working directory

    -n, --dry-run              perform a trial run with no changes made
    -d, --debug                echo duplicity commands to logfile

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:

# You will be prompted for a restore directory
duplicity-backup.sh [-c config_file] --restore

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

Restore a specific file or directory in the backup:

Note that the commands --restore-file and --restore-dir are equivalent.

# You will be prompted for a file to restore to the current directory
duplicity-backup.sh [-c config_file] --restore-file

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

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

# Restores the directory rel/dir/path to /target/restorepath
duplicity-backup.sh [-c config_file] --restore-dir rel/dir/path /target/restorepath

List files in the remote archive

duplicity-backup.sh [-c config_file] --list-current-files

See the collection status (i.e. all the backup sets in the remote archive)

duplicity-backup.sh [-c config_file] --collection-status

Verify the backup

duplicity-backup.sh [-c config_file] --verify

Backup the script and gpg key in a encrypted tarfile (for safekeeping)

duplicity-backup.sh [-c config_file] --backup-script

Cron Usage Example

41 3 * * * /absolute/path/to/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 -d or --debug 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.

You can also try the -n or --dry-run option. This will make duplicity to calculate what would be done, but does not perform any backend actions. Together with info verbosity level (-v8) duplicity will list all files that will be affected. This way you will know exactly which files will be backed up or restored.

Wish List

• send mails only on failure

Thanks to all the contributors for their help.