http(serve): move state outside of serve function, use Extension for examples due to sqlx compile time checking

Author: Nick Miller

Cargo.toml

@@ -20,15 +20,15 @@ name = "demo"
 name = "echo"
 
 [dependencies]
-axum = { version = "0.6.20", features = ["json"] }
+axum = { version = "0.6.20", features = ["json", "macros"] }
 clap = { version = "4", features = ["derive", "env"] }
 once_cell = "1.18"
 prometheus = "0.13"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 tokio = { version = "1.32", features = ["full"] }
 tower = "0.4"
-tower-http = { version = "0.4", features = ["cors", "trace", "map-request-body"] }
+tower-http = { version = "0.4", features = ["cors", "trace", "map-request-body", "util"] }
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["fmt", "std", "json", "env-filter"] }
 

examples/demo/main.rs

@@ -3,7 +3,7 @@
 // SPDX-License-Identifier: AGPL-3.0-or-later
 
 use servus::axum::{
-    extract::{self, State},
+    extract::{self, Extension},
     http::StatusCode,
     response::IntoResponse,
     routing::{get, post},
@@ -25,6 +25,7 @@ struct AppConfig {
     response: String,
 }
 
+#[derive(Clone)]
 struct AppState {
     pool: sqlx::postgres::PgPool,
 }
@@ -56,13 +57,13 @@ async fn main() -> anyhow::Result<()> {
 
     let router = Router::new()
         .route("/message", post(post_message))
-        .route("/message/all", get(get_messages));
+        .route("/message/all", get(get_messages))
+        .layer(Extension(state));
 
     servus::http::serve(
         config.servus.http_address,
         Some(config.servus.metrics_address),
         router,
-        state,
     )
     .await;
 
@@ -76,7 +77,7 @@ struct Message {
 }
 
 async fn post_message(
-    State(state): State<Arc<AppState>>,
+    Extension(state): Extension<Arc<AppState>>,
     extract::Json(payload): extract::Json<Message>,
 ) -> StatusCode {
     info!(
@@ -88,7 +89,7 @@ async fn post_message(
     if let Err(e) = sqlx::query!(
         "INSERT INTO guestbook (author, message) VALUES ($1, $2)",
         payload.author,
-        payload.message
+        payload.message,
     )
     .execute(&state.pool)
     .await
@@ -100,7 +101,7 @@ async fn post_message(
     StatusCode::OK
 }
 
-async fn get_messages(State(state): State<Arc<AppState>>) -> impl IntoResponse {
+async fn get_messages(Extension(state): Extension<Arc<AppState>>) -> impl IntoResponse {
     info!(message = "got get messages request!");
 
     let q = sqlx::query!("select * from guestbook")

examples/echo/main.rs

@@ -25,7 +25,7 @@ async fn main() -> anyhow::Result<()> {
     // Note, we pass the `metrics_address` parameter value as `None` to imply we don't want to
     // start the metrics server. Also, the `state` parameter is the unit type `()`, meaning we have
     // no global state and all handlers are stateless.
-    servus::http::serve(config.servus.http_address, None, router, ()).await;
+    servus::http::serve(config.servus.http_address, None, router).await;
 
     Ok(())
 }

src/http/mod.rs

@@ -32,18 +32,14 @@ use tracing::{error, Level};
 ///
 /// Both the application server and metrics server will respond to a CTRL-C shutdown signal and
 /// terminate gracefully.
-pub async fn serve<S>(
+pub async fn serve(
     http_address: SocketAddr,
     metrics_address: Option<SocketAddr>,
-    router: Router<S>,
-    state: S,
-) where
-    S: Send + Sync + Clone + 'static,
-{
+    router: Router<()>,
+) {
     // create primary application router and server
     // applying handler state if we have it, and default metrics/tracing middleware
-    let r = router
-        .with_state(state)
+    let router = router
         .route_layer(middleware::from_fn(metrics::middleware)) // only record matched routes
         .layer(
             TraceLayer::new_for_http().make_span_with(
@@ -54,17 +50,17 @@ pub async fn serve<S>(
         );
 
     let app = Server::bind(&http_address)
-        .serve(r.into_make_service())
+        .serve(router.into_make_service())
         .with_graceful_shutdown(shutdown_signal());
 
     if let Some(metrics_address) = metrics_address {
         // create metrics router and server, also used for healthcheck
-        let r = Router::new()
+        let router = Router::new()
             .route("/metrics", routing::get(metrics::handler))
             .route("/health", routing::get(health));
 
         let metrics = Server::bind(&metrics_address)
-            .serve(r.into_make_service())
+            .serve(router.into_make_service())
             .with_graceful_shutdown(shutdown_signal());
 
         // spawn each server instance (so they can be scheduled on separate threads as necessary)