examples: Refactor request-id example (#3865)

examples/request-id/Cargo.toml

@@ -8,6 +8,6 @@ publish = false
 axum = { path = "../../axum" }
 tokio = { version = "1.0", features = ["full"] }
 tower = "0.5.2"
-tower-http = { version = "0.6", features = ["request-id", "trace"] }
+tower-http = { version = "0.6", features = ["request-id", "trace", "util"] }
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }

examples/request-id/src/main.rs

@@ -4,22 +4,16 @@
 //! cargo run -p example-request-id
 //! ```
 
-use axum::{
-    http::{HeaderName, Request},
-    response::Html,
-    routing::get,
-    Router,
-};
+use axum::{http::Request, response::Html, routing::get, Router};
 use tower::ServiceBuilder;
 use tower_http::{
-    request_id::{MakeRequestUuid, PropagateRequestIdLayer, SetRequestIdLayer},
+    request_id::{MakeRequestUuid, RequestId},
     trace::TraceLayer,
+    ServiceBuilderExt,
 };
-use tracing::{error, info, info_span};
+use tracing::{info, info_span};
 use tracing_subscriber::{layer::SubscriberExt, util::SubscriberInitExt};
 
-const REQUEST_ID_HEADER: &str = "x-request-id";
-
 #[tokio::main]
 async fn main() {
     tracing_subscriber::registry()
@@ -37,32 +31,21 @@ async fn main() {
         .with(tracing_subscriber::fmt::layer())
         .init();
 
-    let x_request_id = HeaderName::from_static(REQUEST_ID_HEADER);
-
     let middleware = ServiceBuilder::new()
-        .layer(SetRequestIdLayer::new(
-            x_request_id.clone(),
-            MakeRequestUuid,
-        ))
+        .set_x_request_id(MakeRequestUuid)
         .layer(
             TraceLayer::new_for_http().make_span_with(|request: &Request<_>| {
                 // Log the request id as generated.
-                let request_id = request.headers().get(REQUEST_ID_HEADER);
+                let request_id = request.extensions().get::<RequestId>().unwrap();
 
-                match request_id {
-                    Some(request_id) => info_span!(
-                        "http_request",
-                        request_id = ?request_id,
-                    ),
-                    None => {
-                        error!("could not extract request_id");
-                        info_span!("http_request")
-                    }
+                match request_id.header_value().to_str() {
+                    Ok(request_id) => info_span!("http_request", request_id),
+                    Err(_) => info_span!("http_request", request_id = ?request_id),
                 }
             }),
         )
         // send headers from request to response headers
-        .layer(PropagateRequestIdLayer::new(x_request_id));
+        .propagate_x_request_id();
 
     // build our application with a route
     let app = Router::new().route("/", get(handler)).layer(middleware);