Rust actix-web捕获HTTP错误413 (HTTP/1.1 413有效负载太大)

Question

我正在使用actix-web。我想限制post请求的大小，并让web应用程序捕获此错误，将其记录下来，并向用户发送回一条信息性错误消息。

我的代码如下所示。似乎无论是否超过限制，中间件都会运行，并且HTTP代码413被提升。仅当未超过限制时才执行accept_post。

有没有办法在中间件中捕获这个错误？

                .service(
                    web::scope("/hello_someone4")
                        .service(
                            web::resource("/there/*")
                                .app_data(web::PayloadConfig::default().limit(16))
                                .wrap(simple_middleware::simple_middleware_say_hi::SayHi)
                                .route(web::post().to(request_handlers2::accept_post))
                        )
                )

Answer 1

actix_web::middleware::errhandlers中间件提供了我正在寻找的解决方案。

下面的示例代码取自"https://actix.rs/docs/middleware/"。我现在可以向render_413函数添加代码(如下所示)来执行日志记录。

use actix_web::middleware::errhandlers::{ErrorHandlerResponse, ErrorHandlers};
use actix_web::{dev, http, HttpResponse, Result};

fn render_500<B>(mut res: actix_web::dev::ServiceResponse<B>) -> actix_web::Result<actix_web::middleware::errhandlers::ErrorHandlerResponse<B>> {
    res.response_mut()
       .headers_mut()
       .insert(actix_web::http::header::CONTENT_TYPE, actix_web::http::HeaderValue::from_static("Error"));
    Ok(actix_web::middleware::errhandlers::ErrorHandlerResponse::Response(res))
}

fn render_413<B>(mut res: actix_web::dev::ServiceResponse<B>) -> actix_web::Result<actix_web::middleware::errhandlers::ErrorHandlerResponse<B>> {
    res.response_mut()
       .headers_mut()
       .insert(actix_web::http::header::CONTENT_TYPE, actix_web::http::HeaderValue::from_static("413 Error"));
    let req = res.request();
    let res = res.map_body(|_, _| actix_web::body::ResponseBody::Body(actix_web::dev::Body::from("{\"code\":413,\"error\":\"413 Payload Too Large\",\"message\":\"You've sent more data than expected\"}")).into_body());//alter the the response body see "https://users.rust-lang.org/t/actix-web-using-a-custom-error-handler-to-alter-the-response-body/41068"
    Ok(actix_web::middleware::errhandlers::ErrorHandlerResponse::Response(res))
}


#[actix_web::main]
async fn main() -> std::io::Result<()> {
    use actix_web::{web, App, HttpServer};

    HttpServer::new(|| {
        App::new()
                .wrap(
                    actix_web::middleware::errhandlers::ErrorHandlers::new()
                        .handler(actix_web::http::StatusCode::INTERNAL_SERVER_ERROR, render_500),
                )
                .wrap(
                    actix_web::middleware::errhandlers::ErrorHandlers::new()
                        .handler(actix_web::http::StatusCode::PAYLOAD_TOO_LARGE, render_413),
                )
            )
            .service(
                web::resource("/test")
                    .route(web::get().to(|| HttpResponse::Ok()))
                    .route(web::head().to(|| HttpResponse::MethodNotAllowed())),
            )
            .service(
                web::scope("/hello_someone4")
                    .service(
                        web::resource("/there/*")
                            .app_data(web::PayloadConfig::default().limit(16))
                            .wrap(simple_middleware::simple_middleware_say_hi::SayHi)
                            .route(web::post().to(request_handlers2::accept_post))
                    )
            )
    })
    .bind("127.0.0.1:8080")?
    .run()
    .await
}