config via environment variables

[johncantrell97]

I wanted to propose adding support for setting the config via environment variables. They would override anything set in the provided json configuration file. Could also make the config path argument optional and the binary would fail to startup if it cannot get a full Config via env vars.

This repo does not have a Discussion section so adding as an issue.

[G8XSU]

Support for setting some configuration values as environment variables definitely makes sense.
However, I am not sure if we should support the entire configuration through environment variables.

I understand the use case for few dynamic values or sensitive data, but are there any other advantages to full config through env vars?

One concern, although minor, is that having multiple sources of configuration could make debugging production deployments during operations more confusing.

[moisesPompilio]

I'd like to support this proposal and suggest the following behavior regarding environment variables:

1. Use environment variables to fully configure a node

It would be very helpful if all the essential configuration needed to start the node could be set via environment variables — without requiring a .toml file. This is especially useful for containerized deployments or dynamic environments (e.g., testing, CI, fuzzing).

2. Environment variables should override values from the .toml file

When both a .toml file and environment variables are provided, the values from the environment variables should take precedence. This allows using a common base .toml file with dynamic overrides, without having to create separate config files per environment.

Suggested environment variables

Here’s a set of variables I think would cover the core configuration needed to bootstrap an LDK node:

--node-network = "regtest"                        # Bitcoin network to use
--node-listening_address = "localhost:3001"       # Lightning node listening address
--node-rest_service_address = "127.0.0.1:3002"    # LDK server REST API address
--bitcoind-rpc_address = "127.0.0.1:18444"        # Bitcoin Core RPC address
--bitcoind-rpc-user = "user"                      # RPC username
--bitcoind-rpc-password = "password"              # RPC password
--storage-dir-path = "/tmp/ldk-server/"           # Path to store LDK/BDK data

[tnull]

I think the change you propose makes sense. Might be good to prefix all variables with LDK_SERVER_ to avoid any conflicts.

[Anyitechs]

Hey! Anyone currently working on this? I would love to work on the proposal.

[moisesPompilio]

Hi @Anyitechs ! I'm working on this issue.