refactor: rename some examples (#7881)

examples/node-custom-rpc/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "node-custom-rpc"
+version = "0.0.0"
+publish = false
+edition.workspace = true
+license.workspace = true
+
+[dependencies]
+reth.workspace = true
+reth-transaction-pool.workspace = true
+reth-node-ethereum.workspace = true
+
+clap = { workspace = true, features = ["derive"] }
+jsonrpsee = { workspace = true, features = ["server", "macros"] }
+eyre.workspace = true
+
+[dev-dependencies]
+tokio.workspace = true

examples/node-custom-rpc/src/main.rs

@@ -0,0 +1,110 @@
+//! Example of how to use additional rpc namespaces in the reth CLI
+//!
+//! Run with
+//!
+//! ```not_rust
+//! cargo run -p node-custom-rpc -- node --http --ws --enable-ext
+//! ```
+//!
+//! This installs an additional RPC method `txpoolExt_transactionCount` that can be queried via [cast](https://github.com/foundry-rs/foundry)
+//!
+//! ```sh
+//! cast rpc txpoolExt_transactionCount
+//! ```
+
+use clap::Parser;
+use jsonrpsee::{core::RpcResult, proc_macros::rpc};
+use reth::cli::Cli;
+use reth_node_ethereum::EthereumNode;
+use reth_transaction_pool::TransactionPool;
+
+fn main() {
+    Cli::<RethCliTxpoolExt>::parse()
+        .run(|builder, args| async move {
+            let handle = builder
+                .node(EthereumNode::default())
+                .extend_rpc_modules(move |ctx| {
+                    if !args.enable_ext {
+                        return Ok(())
+                    }
+
+                    // here we get the configured pool.
+                    let pool = ctx.pool().clone();
+
+                    let ext = TxpoolExt { pool };
+
+                    // now we merge our extension namespace into all configured transports
+                    ctx.modules.merge_configured(ext.into_rpc())?;
+
+                    println!("txpool extension enabled");
+
+                    Ok(())
+                })
+                .launch()
+                .await?;
+
+            handle.wait_for_node_exit().await
+        })
+        .unwrap();
+}
+
+/// Our custom cli args extension that adds one flag to reth default CLI.
+#[derive(Debug, Clone, Copy, Default, clap::Args)]
+struct RethCliTxpoolExt {
+    /// CLI flag to enable the txpool extension namespace
+    #[arg(long)]
+    pub enable_ext: bool,
+}
+
+/// trait interface for a custom rpc namespace: `txpool`
+///
+/// This defines an additional namespace where all methods are configured as trait functions.
+#[cfg_attr(not(test), rpc(server, namespace = "txpoolExt"))]
+#[cfg_attr(test, rpc(server, client, namespace = "txpoolExt"))]
+pub trait TxpoolExtApi {
+    /// Returns the number of transactions in the pool.
+    #[method(name = "transactionCount")]
+    fn transaction_count(&self) -> RpcResult<usize>;
+}
+
+/// The type that implements the `txpool` rpc namespace trait
+pub struct TxpoolExt<Pool> {
+    pool: Pool,
+}
+
+impl<Pool> TxpoolExtApiServer for TxpoolExt<Pool>
+where
+    Pool: TransactionPool + Clone + 'static,
+{
+    fn transaction_count(&self) -> RpcResult<usize> {
+        Ok(self.pool.pool_size().total)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use jsonrpsee::{http_client::HttpClientBuilder, server::ServerBuilder};
+    use reth_transaction_pool::noop::NoopTransactionPool;
+
+    #[tokio::test(flavor = "multi_thread")]
+    async fn test_call_transaction_count_http() {
+        let server_addr = start_server().await;
+        let uri = format!("http://{}", server_addr);
+        let client = HttpClientBuilder::default().build(&uri).unwrap();
+        let count = TxpoolExtApiClient::transaction_count(&client).await.unwrap();
+        assert_eq!(count, 0);
+    }
+
+    async fn start_server() -> std::net::SocketAddr {
+        let server = ServerBuilder::default().build("127.0.0.1:0").await.unwrap();
+        let addr = server.local_addr().unwrap();
+        let pool = NoopTransactionPool::default();
+        let api = TxpoolExt { pool };
+        let server_handle = server.start(api.into_rpc());
+
+        tokio::spawn(server_handle.stopped());
+
+        addr
+    }
+}