Finish off a mirror service.

Cargo.toml

@@ -17,3 +17,4 @@ section = "web"
 
 [dependencies]
 actix-web = "4"
+serde = { version = "1.0", features = ["derive"] }

src/main.rs

@@ -1,3 +1,49 @@
-fn main() {
-    println!("Hello, world!");
+use actix_web::{web::Json, App, HttpRequest, HttpServer, Responder};
+use serde::Serialize;
+
+#[derive(Serialize)]
+struct EchoHeader {
+    name: String,
+    value: String,
+}
+
+#[derive(Serialize)]
+struct EchoResponse {
+    method: String,
+    path: String,
+    host: String,
+    headers: Vec<EchoHeader>,
+}
+
+impl EchoResponse {
+    fn new(req: &HttpRequest) -> Self {
+        let req_uri = req.uri();
+        let headers = req
+            .headers()
+            .iter()
+            .map(|(header_name, header_value)| EchoHeader {
+                name: header_name.to_string(),
+                value: header_value.to_str().unwrap_or("ERROR").to_string(),
+            })
+            .collect::<Vec<EchoHeader>>();
+        EchoResponse {
+            method: req.method().to_string(),
+            path: req_uri.path().to_string(),
+            host: req_uri.host().unwrap_or("").to_string(),
+            headers,
+        }
+    }
+}
+
+async fn echo_request(request: HttpRequest) -> actix_web::Result<impl Responder> {
+    let echo = EchoResponse::new(&request);
+    Ok(Json(echo))
+}
+
+#[actix_web::main]
+async fn main() -> std::io::Result<()> {
+    HttpServer::new(|| App::new().default_service(actix_web::web::route().to(echo_request)))
+        .bind(("0.0.0.0", 8080))?
+        .run()
+        .await
 }