pisync is a simple library to aid in writing incremental backup scripts to local or remote machines. The only dependencies are rsync, python >= v3.6, fabric, and ssh keys copied over to a unix machine if doing a remote backup. Note: no dependencies are required on the remote machine.

Installation

pip install pisync

Example Usage

from pisync import LocalConfig, RemoteConfig, backup

local_docs = LocalConfig(
    source_dir="/home/ethan/Documents", # local machine
    destination_dir="/tmp/backup_test", # local machine
    exclude_file_patterns=[
        "**/node_modules",
        "junk/",
    ],
    log_file="/tmp/backup-logs/backups.log" # local machine
)

remote_docs = RemoteConfig(
    user_at_hostname="ethan@hydrogen.local", # remote machine
    source_dir="/home/ethan/Documents", # local machine
    destination_dir="/tmp/backup_test", # remote machine
    exclude_file_patterns=[
        "**/node_modules",
        "junk/",
    ],
    log_file="/tmp/backup-logs/backups.log" # local machine
)

backup(local_docs)
backup(remote_docs)

Also see an example config for how I backup my home server both locally and to an offsite raspberry pi.

Notes

Safety

• Creating a LocalConfig or RemoteConfig object will fail if source_dir or destination_dir do not exist or are not directories.
• If destination_dir is not empty, it is assumed that a previous backup exists.
  • The backup will not run if destination_dir is not empty and there is not a symlink destination_dir/latest pointing to the latest backup.
  • The contents of source_dir are compared to destination_dir/latest during the incremental backup and the changes are written to destination_dir/<current date/time>.
  • Therefore, you need to ensure that destination_dir is empty which will start a fresh complete backup, or you can manually create the destination_dir/latest symlink to continue incrementally.

Logging

• By default, a default log file will be created (if it does not exists) and appended to at ~/.local/share/backup/rsync-backups.log.
• NOTE: If you run your script as sudo, the home directory of the root user is probably /root rather than your ~/ directory.
• If you want the log file to still go the your home directory when you run as root, use this sudo -E python3 ./run_backups.py
• You can also specify the log file location in your config.
  • Hard coding the log file path solves some of the quirks that you can run into when using a cron job.

Running tests

The unit/integration tests require password-less login to localhost as the "remote" machine.

ssh-copy-id $USER@localhost
git clone https://github.com/erietz/pisync
cd pisync
pip install -e .
make test