rust - 如何在Rust中将变量传递给actix-web guard()？

Question

#[actix_rt::main]
async fn main() -> std::io::Result<()> {

    let token = env::var("TOKEN").expect("Set TOKEN");

    HttpServer::new(|| {
        App::new()
            .wrap(middleware::Logger::default())
            .service(
                web::resource("/")
                    .guard(guard::Header("TOKEN", &token))
                    .route(web::post().to(index))
            )
    })
        .bind("127.0.0.1:8080")?
        .run()
        .await
}

错误是:

error[E0597]: `token` does not live long enough

我在actix文档中看到了 .data()，但这是用于在路由函数内部传递变量的。
UPD:
如果我添加“移动”:

HttpServer::new(move || {

然后只是错误更改:

error[E0495]: cannot infer an appropriate lifetime for borrow expression due to conflicting requirements
  --> src/main.rs:50:58
   |
50 |                     .guard(guard::Header("TOKEN", &token))
   |                                                    ^^^^^^
   |
note: first, the lifetime cannot outlive the lifetime `'_` as defined on the body at 42:21...
  --> src/main.rs:42:21
   |
42 |     HttpServer::new(move || {
   |                     ^^^^^^^
note: ...so that closure can access `token`
  --> src/main.rs:50:58
   |
50 |                     .guard(guard::Header("TOKEN", &token))
   |                                                    ^^^^^^
   = note: but, the lifetime must be valid for the static lifetime...
note: ...so that reference does not outlive borrowed content
  --> src/main.rs:50:58
   |
50 |                     .guard(guard::Header("TOKEN", &token))
   |                                                    ^^^^^^

error: aborting due to previous error

Answer 1

actix-web创建了许多线程，并且每个工作人员(在每个线程中)必须获取变量的副本。因此，使用let token = token.clone();和move。
之后，这些变量中的每一个都进入fn_guard函数。因此，再次move。

let token = env::var("TOKEN").expect("You must set TOKEN");

HttpServer::new(move || {
    let token = token.clone();

    App::new()
        .wrap(middleware::Logger::default())
        .service(
            web::resource("/")
                .guard(guard::fn_guard(
                    move |req| match req.headers().get("TOKEN") {
                        Some(value) => value == token.as_str(),
                        None => false,
                    }))
                .route(web::post().to(index))
        )
})
    .bind("127.0.0.1:8080")?
    .run()
    .await

这行得通。
仅使用 .guard(guard::Header("TOKEN", &token))无法使其工作