ldk-sample

Sample node implementation using LDK.

Installation

git clone https://github.com/lightningdevkit/ldk-sample

Usage

cd ldk-sample
cargo run <ldk_storage_directory_path>

The only CLI argument is the storage directory path. All configuration is read from <ldk_storage_directory_path>/.ldk/config.toml.

Use config.example.toml in the repo root as a template for your config file.

Configuration

Config is loaded from <storage_dir>/.ldk/config.toml and strictly validated. Unknown fields cause an error (deny_unknown_fields).

Required sections: bitcoind. Optional sections: ldk, rapid_gossip_sync, probing (probing is disabled if missing), and dns_bootstrap (enabled by default with sensible defaults).

Network options: mainnet, testnet, regtest, signet (default is testnet).

Example config

network = "testnet"

[bitcoind]
rpc_host = "127.0.0.1"
rpc_port = 8332
rpc_username = "your_rpc_user"
rpc_password = "your_rpc_password"

# [ldk]
# peer_listening_port = 9735
# announced_node_name = "MyLDKNode"
# announced_listen_addr = []

[rapid_gossip_sync]
enabled = true
url = "https://rapidsync.lightningdevkit.org/snapshot/"
interval_hours = 6

[probing]
interval_sec = 300
peers = ["02abc123...@1.2.3.4:9735"]
amount_msats = [1000, 10000, 100000, 1000000]
timeout_sec = 60

probe_delay_sec = 1
peer_delay_sec = 2

[dns_bootstrap]
enabled = true
seeds = [ "nodes.lightning.wiki", "lseed.bitcoinstats.com" ]
timeout_secs = 30
num_peers = 10
interval_secs = 300

Key options

bitcoind: RPC details are required. rpc_username and rpc_password can usually be found via cat ~/.bitcoin/.cookie.

ldk: peer_listening_port defaults to 9735. announced_listen_addr and announced_node_name default to empty, disabling public announcements. announced_listen_addr can be set to an IPv4 or IPv6 address to announce a publicly-connectable address. announced_node_name can be any string up to 32 bytes, representing this node's alias.

rapid_gossip_sync: Enabled by default to speed up initial network graph sync. On startup, the node attempts a RapidGossipSync download up to 3 times with exponential backoff. If it fails, the node falls back to P2P gossip sync. url defaults to https://rapidsync.lightningdevkit.org/snapshot/, interval_hours defaults to 6.

probing: Optional. If omitted, probing is disabled. Configure probe interval, peers, probe amounts in millisatoshis, and timeout.

dns_bootstrap: Optional. Enabled by default. Discovers peers via DNS SRV lookups per BOLT-0010. seeds defaults to nodes.lightning.wiki and lseed.bitcoinstats.com. timeout_secs defaults to 30, num_peers defaults to 10, interval_secs defaults to 300. Set enabled to false to disable.

License

Licensed under either:

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT License (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.