Revert hello_world example

Accidentally changed it while testing something

examples/hello_world.rs

@@ -1,24 +1,26 @@
+//! Run with
+//!
+//! ```not_rust
+//! cargo run --example hello_world
+//! ```
+
 use axum::prelude::*;
-use std::{convert::Infallible, net::SocketAddr, time::Duration};
+use std::net::SocketAddr;
-use tower::{limit::RateLimitLayer, BoxError, ServiceBuilder};
 
 #[tokio::main]
 async fn main() {
-    let handler_layer = ServiceBuilder::new()
+    // Set the RUST_LOG, if it hasn't been explicitly defined
-        .buffer(1024)
+    if std::env::var("RUST_LOG").is_err() {
-        .layer(RateLimitLayer::new(10, Duration::from_secs(10)))
+        std::env::set_var("RUST_LOG", "hello_world=debug")
-        .into_inner();
+    }
+    tracing_subscriber::fmt::init();
 
-    let app = route(
+    // build our application with a route
-        "/",
+    let app = route("/", get(handler));
-        get(handler
-            .layer(handler_layer)
-            .handle_error(|error: BoxError| {
-                Ok::<_, Infallible>(format!("Unhandled error: {}", error))
-            })),
-    );
 
+    // run it
     let addr = SocketAddr::from(([127, 0, 0, 1], 3000));
+    tracing::debug!("listening on {}", addr);
     axum::Server::bind(&addr)
         .serve(app.into_make_service())
         .await