cln-grpc-plugin: Add basic grpc-plugin

plugins/grpc-plugin/Cargo.toml

@@ -0,0 +1,27 @@
+[package]
+edition = "2021"
+name = "grpc-plugin"
+version = "0.1.0"
+
+[dependencies]
+anyhow = "1.0"
+log = "0.4"
+prost = "0.8"
+rcgen = { version = "0.8", features = ["pem", "x509-parser"] }
+
+[dependencies.cln-grpc]
+path = "../../cln-grpc"
+
+[dependencies.cln-plugin]
+path = "../../plugins"
+
+[dependencies.cln-rpc]
+path = "../../cln-rpc"
+
+[dependencies.tokio]
+features = ["net", "rt-multi-thread"]
+version = "1"
+
+[dependencies.tonic]
+features = ["tls", "transport"]
+version = "^0.5"

plugins/grpc-plugin/src/main.rs

@@ -0,0 +1,52 @@
+use anyhow::{Context, Result};
+use cln_grpc::pb::node_server::NodeServer;
+use cln_plugin::Builder;
+use log::{debug, warn};
+use std::net::SocketAddr;
+use std::path::{Path, PathBuf};
+
+#[derive(Clone, Debug)]
+struct PluginState {
+    rpc_path: PathBuf,
+    bind_address: SocketAddr,
+}
+
+#[tokio::main]
+async fn main() -> Result<()> {
+    debug!("Starting grpc plugin");
+    let path = Path::new("lightning-rpc");
+    let addr: SocketAddr = "0.0.0.0:50051".parse().unwrap();
+
+    let state = PluginState {
+        rpc_path: path.into(),
+        bind_address: addr,
+    };
+
+    let (plugin, i) = Builder::new(state.clone(), tokio::io::stdin(), tokio::io::stdout()).build();
+
+    tokio::spawn(async move {
+        if let Err(e) = run_interface(state).await {
+            warn!("Error running the grpc interface: {}", e);
+        }
+    });
+
+    plugin.join().await
+}
+
+async fn run_interface(state: PluginState) -> Result<()> {
+    debug!(
+        "Connecting to {:?} and serving grpc on {:?}",
+        &state.rpc_path, &state.bind_address
+    );
+    tonic::transport::Server::builder()
+        .add_service(NodeServer::new(
+            cln_grpc::Server::new(&state.rpc_path)
+                .await
+                .context("creating NodeServer instance")?,
+        ))
+        .serve(state.bind_address)
+        .await
+        .context("serving requests")?;
+
+    Ok(())
+}