LND auto backup service

This is a channel backup script for LND node (prepared to be installed as a systemd service).

The script uses inotifywait to monitor for file changes and triggers a new time-stamped backup when needed. The backup script can do anything. As an example, we provide optional backup to Amazon S3 or via rsync. Or you can specify your own custom script.

See https://github.com/lightningnetwork/lnd/pull/2313 for details.

More reading

• Alex Bosworth's example
• Patrick Lemke's medium post
• Rahil Shaikh's medium post

Prerequisites

• apt install inotify-tools

Setup

1. git clone --depth=1 https://github.com/darwin/lnd-auto-backup.git
2. cd lnd-auto-backup
3. create a .envrc with content:

# for S3 backup (optional)
# also don't forget to `apt install awscli`
# note: S3 secrets can be configured via `aws configure`
export LNDAB_S3_BUCKET=your_bucket_name 

# for rsync backup (optional)
# note: ssh access keys must be configured on the machine
export LNDAB_RSYNC_TARGET=user@server:/remote/path/to/backup/dir

# for custom backup (optional)
export LNDAB_CUSTOM_BACKUP_SCRIPT=path/to/your/script.sh 

# these are optional:
#
#   export LND_HOME=/root/.lnd # if differs from $HOME/.lnd
#   export LND_NETWORK=mainnet
#   export LND_CHAIN=bitcoin
#   export LNDAB_CHANNEL_BACKUP_PATH=/custom/path/to/channel.backup
#   export LNDAB_VERBOSE=1
#   export LNDAB_S3_BACKUP_SCRIPT=./backup-via-s3.sh
#   export LNDAB_RSYNC_BACKUP_SCRIPT=./backup-via-rsync.sh

4. modify LNDAB_HOME in ./service/lnd-auto-backup.service to point to the right directory, also review other service settings
5. ./service/install.sh
6. ./service/start.sh - start it!
7. ./service/status.sh - just to check the status
8. ./service/enable.sh - if it looks good, enable service launching after system restart

Note: The service runs under the root privileges by default. You can change it by setting User/Group in .service config file. You should perform aws configure under the same user. Or make sure $HOME/.aws folder is at expected place with correct permissions.

Typical workflow

Run it directly (for testing)

1. set env vars, or source .envrc or better use direnv
2. ./monitor.sh

Check that the backup is working

touch /path/to/.lnd/data/chain/bitcoin/mainnet/channel.backup

See service logs

./service/logs.sh

See service status

./service/status.sh

Stop the service

./service/stop.sh

Disable the service

./service/disable.sh

Update from git

cd lnd-auto-backup
git pull
./service/restart.sh 
# you may be prompted to do `systemctl daemon-reload` if needed, then you need to restart it again

Tested on Ubuntu 19.04 server. My lnd node runs in a docker container and I use this service to monitor changes of channel.backup file mapped to host machine via a docker volume.

My pubkey starts with 03e24db0