This plugin will maintain clean database backups to another location. It uses the db_write hook to make sure to always have a backup that isn't missing any states and be potentially harmful.

Installation

There are some python dependencies. You can install them using pip:

pip3 install --user -r requirements.txt

Setup

Before using the backup pluging it has to be initialized once. The following command will create a backup.lock file lightning directoy that stores the internal state and makes sure that not two or more instances are using the same backup.

./backup-cli init ~/.lightning/bitcoin file:///mnt/external/location

Notes:

Make sure to adjust your ~/.lightning/bitcoin directory to your needs.
You should use some non-local SSH or NFS mount as destination.
Currently only file:/// URL scheme is supported.

IMPORTANT note about hsm_secret

You need to secure your nodes ~/.lightning/bitcoin/hsm_secret once! This file will not change, but without this file, you won't be able to use your database backup!

Make sure it has user read only permissions, otherwise lightningd will refuse to work: chmod 0400 hsm_secret

Running

In order to tell lightningd to use the plugin you either need to tell it via the startup option --plugin /path/to/backup.py or by placing it (or a symlink to it) in the lightning dir's plugin directory (~/.lightning/plugins).

On daemon startup the plugin will check for the integrity of last prior backup and complain if theres a mismatch.

Restoring a backup

If things really messed up and you reinstall clightning on a new host, you can restore the database backup by using the backup-cli utility:

./backup-cli restore file:///mnt/external/location ~/.lightning/bitcoin/lightningd.sqlite3