Add example showing how to run axum on hyper 1.0 (#1791)

examples/hyper-1-0/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "example-hyper-1-0"
+version = "0.1.0"
+edition = "2021"
+publish = false
+
+[dependencies]
+axum = { path = "../../axum" }
+hyper = { version = "1.0.0-rc.3", features = ["full"] }
+tokio = { version = "1.0", features = ["full"] }
+tower-http = { version = "0.4", features = ["trace"] }
+tower-hyper-http-body-compat = { version = "0.1", features = ["http1", "server"] }
+tracing = "0.1"
+tracing-subscriber = { version = "0.3", features = ["env-filter"] }

examples/hyper-1-0/src/main.rs

@@ -0,0 +1,55 @@
+//! Run with
+//!
+//! ```not_rust
+//! cd examples && cargo run -p example-hyper-1-0
+//! ```
+
+use axum::{routing::get, Router};
+use std::net::SocketAddr;
+use tokio::net::TcpListener;
+use tower_http::trace::TraceLayer;
+use tower_hyper_http_body_compat::{
+    HttpBody1ToHttpBody04, TowerService03HttpServiceAsHyper1HttpService,
+};
+use tracing_subscriber::{layer::SubscriberExt, util::SubscriberInitExt};
+
+// this is hyper 1.0
+use hyper::{body::Incoming, server::conn::http1};
+
+#[tokio::main]
+async fn main() {
+    tracing_subscriber::registry()
+        .with(
+            tracing_subscriber::EnvFilter::try_from_default_env()
+                .unwrap_or_else(|_| "example_hyper_1_0=debug".into()),
+        )
+        .with(tracing_subscriber::fmt::layer())
+        .init();
+
+    // you have to use `HttpBody1ToHttpBody04<Incoming>` as the second type parameter to `Router`
+    let app: Router<_, HttpBody1ToHttpBody04<Incoming>> = Router::new()
+        .route("/", get(|| async { "Hello, World!" }))
+        // we can still add regular tower middleware
+        .layer(TraceLayer::new_for_http());
+
+    // `Router` implements tower-service 0.3's `Service` trait. Convert that to something
+    // that implements hyper 1.0's `Service` trait.
+    let service = TowerService03HttpServiceAsHyper1HttpService::new(app);
+
+    let addr = SocketAddr::from(([127, 0, 0, 1], 3000));
+    let tcp_listener = TcpListener::bind(addr).await.unwrap();
+    tracing::debug!("listening on {addr}");
+    loop {
+        let (tcp_stream, _) = tcp_listener.accept().await.unwrap();
+        let service = service.clone();
+        tokio::task::spawn(async move {
+            if let Err(http_err) = http1::Builder::new()
+                .keep_alive(true)
+                .serve_connection(tcp_stream, service)
+                .await
+            {
+                eprintln!("Error while serving HTTP connection: {http_err}");
+            }
+        });
+    }
+}