Updates

reference_jsonrpsee_crate_examples/http_proxy_middleware.rs

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+// Copyright 2019-2022 Parity Technologies (UK) Ltd.
+//
+// Permission is hereby granted, free of charge, to any
+// person obtaining a copy of this software and associated
+// documentation files (the "Software"), to deal in the
+// Software without restriction, including without
+// limitation the rights to use, copy, modify, merge,
+// publish, distribute, sublicense, and/or sell copies of
+// the Software, and to permit persons to whom the Software
+// is furnished to do so, subject to the following
+// conditions:
+//
+// The above copyright notice and this permission notice
+// shall be included in all copies or substantial portions
+// of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+// ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+// TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+// PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+// SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+// IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+//! This example utilizes the `ProxyRequest` layer for redirecting
+//! `GET /path` requests to internal RPC methods.
+//!
+//! The RPC server registers a method named `system_health` which
+//! returns `serde_json::Value`. Redirect any `GET /health`
+//! requests to the internal method, and return only the method's
+//! response in the body (ie, without any jsonRPC 2.0 overhead).
+//!
+//! # Note
+//!
+//! This functionality is useful for services which would
+//! like to query a certain `URI` path for statistics.
+
+use hyper_util::client::legacy::Client;
+use hyper_util::rt::TokioExecutor;
+use std::net::SocketAddr;
+use std::time::Duration;
+
+use jsonrpsee::core::client::ClientT;
+use jsonrpsee::http_client::HttpClient;
+use jsonrpsee::rpc_params;
+use jsonrpsee::server::middleware::http::ProxyGetRequestLayer;
+use jsonrpsee::server::{RpcModule, Server};
+
+type EmptyBody = http_body_util::Empty<hyper::body::Bytes>;
+
+#[tokio::main]
+async fn main() -> anyhow::Result<()> {
+	tracing_subscriber::FmtSubscriber::builder()
+		.with_env_filter(tracing_subscriber::EnvFilter::from_default_env())
+		.try_init()
+		.expect("setting default subscriber failed");
+
+	let addr = run_server().await?;
+	let url = format!("http://{}", addr);
+
+	// Use RPC client to get the response of `say_hello` method.
+	let client = HttpClient::builder().build(&url)?;
+	let response: String = client.request("say_hello", rpc_params![]).await?;
+	println!("[main]: response: {:?}", response);
+
+	// Use hyper client to manually submit a `GET /health` request.
+	let http_client = Client::builder(TokioExecutor::new()).build_http();
+	let uri = format!("http://{}/health", addr);
+
+	let req = hyper::Request::builder().method("GET").uri(&uri).body(EmptyBody::new())?;
+	println!("[main]: Submit proxy request: {:?}", req);
+	let res = http_client.request(req).await?;
+	println!("[main]: Received proxy response: {:?}", res);
+
+	// Interpret the response as String.
+	let collected = http_body_util::BodyExt::collect(res.into_body()).await?;
+	let out = String::from_utf8(collected.to_bytes().to_vec()).unwrap();
+	println!("[main]: Interpret proxy response: {:?}", out);
+	assert_eq!(out.as_str(), "{\"health\":true}");
+
+	Ok(())
+}
+
+async fn run_server() -> anyhow::Result<SocketAddr> {
+	// Custom tower service to handle the RPC requests
+	let service_builder = tower::ServiceBuilder::new()
+		// Proxy `GET /health` requests to internal `system_health` method.
+		.layer(ProxyGetRequestLayer::new([("/health", "system_health")])?)
+		.timeout(Duration::from_secs(2));
+
+	let server =
+		Server::builder().set_http_middleware(service_builder).build("127.0.0.1:0".parse::<SocketAddr>()?).await?;
+
+	let addr = server.local_addr()?;
+
+	let mut module = RpcModule::new(());
+	module.register_method("say_hello", |_, _, _| "lo").unwrap();
+	module.register_method("system_health", |_, _, _| serde_json::json!({ "health": true })).unwrap();
+
+	let handle = server.start(module);
+
+	// In this example we don't care about doing shutdown so let's it run forever.
+	// You may use the `ServerHandle` to shut it down or manage it yourself.
+	tokio::spawn(handle.stopped());
+
+	Ok(addr)
+}