A short guide on how to setup and configure a new lightning node using LND with recently released PostgreSQL support as database backend. The approach was done by creating a new lightning node. To date, backend data migrations are still being developed. A brief write-up for PostgreSQL support was released by Lightning Labs here: postgres.md. Nevertheless it lacks important parts which this guide wants to cover step by step.
The guide is based on the following setup and components. It may be different for Umbrel / Raspiblitz / MyNode installations as it was established on a bolt / bare metal setup running Ubuntu.
It’s important to emphasize that this setup is built as a new lightning node without existing funds or channels. As said, data migrations between different backends (bbolt, postgres, etcd) are not yet supported (as of v0.14.3).
Installation process of LND is omitted in this guide as this is widely described on the internet. So I assume a valid installation here and continue to setup the backend:
# Install postgresql-14
$ sudo apt install postgresql-14
# Configure postgresql to your needs (port, datadir, logging, etc.) or use default values.
$ sudo nano /etc/postgresql/14/main/postgresql.conf
# Setup postgres user
$ sudo -i -u postgres
$ psql
postgres=# \password
# Enter password and take note of it!
# Quit PSQL
\q
Create user and database for LND:
# As postgres user
$ sudo -i -u postgres
# Create user 'lnd' and set a password
$ createuser --createdb --pwprompt lnd
# Enter password and take note of it!
# Create database 'lndb'
$ createdb -O lnd lndb
# Exit user postgres
$ exit
Configure your lnd.conf:
$ sudo nano /home/lnd/.lnd/lnd.conf
Edit and add your postgresql config and credentials, like so: postgresql://<user>:<pw>@<ip>:<port>/<db>
[db]
db.backend=postgres
[postgres]
db.postgres.dsn=postgresql://lnd:password@127.0.0.1:5432/lndb?sslmode=disable
db.postgres.timeout=0
Add postgres as a requirement to LND’s systemd service:
[Unit]
Description=...
Requires=postgresql@.service bitcoind.service
After=postgresql@.service bitcoind.service
If everything went fine, you can see this in the lnd.log:
[INF] LTND: Opening the main database, this might take a few minutes...
[INF] LTND: Using remote postgres database! Creating graph and channel state DB instances
Upgrading PostgreSQL should be easy using Postgres’ own tool pg_upgrade. Install and setup next version in parallel. Upgrade to new datadir, dry-run before doing the command (--check = dry-run) from v13 to v14:
/usr/lib/postgresql/14/bin/pg_upgrade \
--old-datadir=/var/lib/postgresql/13/main \
--new-datadir=/var/lib/postgresql/14/main \
--old-bindir=/usr/lib/postgresql/13/bin \
--new-bindir=/usr/lib/postgresql/14/bin \
--old-options '-c config_file=/etc/postgresql/13/main/postgresql.conf' \
--new-options '-c config_file=/etc/postgresql/14/main/postgresql.conf' \
--check
For more details on this topic, see link in addendum part below.