[router] Add /list_workers endpoint to router (#6366)

sgl-router/src/server.rs

@@ -132,6 +132,13 @@ async fn add_worker(
     }
 }
 
+#[get("/list_workers")]
+async fn list_workers(data: web::Data<AppState>) -> impl Responder {
+    let workers = data.router.get_worker_urls();
+    let worker_list = workers.read().unwrap().clone();
+    HttpResponse::Ok().json(serde_json::json!({ "urls": worker_list }))
+}
+
 #[post("/remove_worker")]
 async fn remove_worker(
     query: web::Query<HashMap<String, String>>,
@@ -253,6 +260,7 @@ pub async fn startup(config: ServerConfig) -> std::io::Result<()> {
             .service(get_server_info)
             .service(add_worker)
             .service(remove_worker)
+            .service(list_workers)
             // Default handler for unmatched routes.
             .default_service(web::route().to(sink_handler))
     })