LND gRPC Client in Rust.

Rust 🦀 implementation of LND RPC client using async gRPC library tonic_openssl.

About

This crate implements LND GRPC using tonic_openssl and prost. Apart from being up-to-date at the time of writing (:D) it also allows async usage. It contains vendored *.proto files so LND source code is not required but accepts an environment variable LND_REPO_DIR which overrides the vendored *.proto files. This can be used to test new features in non-released lnd.

Adding to your Rust 🦀 project

cargo add lnd_grpc_rust

This crate uses OpenSSL through tonic_openssl. By default it links against a system OpenSSL installation. On Windows, or in CI environments where OpenSSL is not installed or not discoverable, enable the vendored OpenSSL feature so Cargo builds OpenSSL from source:

cargo add lnd_grpc_rust --features vendored-openssl

Or add it manually:

lnd_grpc_rust = { version = "2.14", features = ["vendored-openssl"] }

The vendored feature makes setup more portable, but it increases build time.

Usage

There's no setup needed beyond adding the crate to your Cargo.toml. If you need to change the *.proto files from which the client is generated, set the environment variable LND_REPO_DIR to a directory with cloned lnd during build.

Here's an example of retrieving information from LND ([getinfo](https://api.lightning.community/#getinfo) call). You can find the same example in crate root for your convenience.

Connect function takes cert and macaroon in hex format.

use std::fs;

#[tokio::main]
async fn main() {
        // Read the contents of the file into a vector of bytes
        let cert_bytes = fs::read("/path/to/tls.cert").expect("FailedToReadTlsCertFile");
        let mac_bytes = fs::read("path/to/macaroon").expect("FailedToReadMacaroonFile");

       // Convert the bytes to a hex string
        let cert = buffer_as_hex(cert_bytes);
        let macaroon = buffer_as_hex(mac_bytes);
        let socket = "localhost:10001".to_string();

        let mut client = lnd_grpc_rust::connect(cert, macaroon, socket)
        .await
        .expect("failed to connect");

    let info = client
        .lightning()
        // All calls require at least empty parameter
        .get_info(lnd_grpc_rust::lnrpc::GetInfoRequest {})
        .await
        .expect("failed to get info");

    // We only print it here, note that in real-life code
    // you may want to call `.into_inner()`
    // on the response to get the message.
    println!("{:#?}", info);
}

fn buffer_as_hex(bytes: Vec<u8>) -> String {
    let hex_str = bytes.iter().map(|b| format!("{:02x}", b)).collect::<String>();

    return hex_str;
}

Connecting to multiple nodes

Use connect_nodes when you want to manage several LND connections at once. Each node gets an alias, and the returned registry can look clients up by that alias.

let nodes = vec![
    lnd_grpc_rust::LndNodeConfig::new(
        "alice",
        alice_cert,
        alice_macaroon,
        "localhost:10001",
    ),
    lnd_grpc_rust::LndNodeConfig::new(
        "bob",
        bob_cert,
        bob_macaroon,
        "localhost:10002",
    ),
];

let mut clients = lnd_grpc_rust::connect_nodes(nodes)
    .await
    .expect("failed to connect nodes");

let alice_info = clients
    .get_mut("alice")
    .expect("missing alice node")
    .lightning()
    .get_info(lnd_grpc_rust::lnrpc::GetInfoRequest {})
    .await
    .expect("failed to get alice info");

println!("{:#?}", alice_info);

License

MIT