How to pass a variable to actix-web guard() in Rust?

user_388427 0
Viewed 1012
#[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
}

The error is:

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

I saw .data() in actix docs but that is for passing variables inside routes functions.

UPD:

If I add "move":

HttpServer::new(move || {

then just error changes:

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
actix-web rust
1 Answers

actix-web creates many threads and each worker (in each thread) must get a copy of a variable. So using let token = token.clone(); and move.

After that each of these variables goes into fn_guard function. So once again 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

This works.

Can't get it working with only .guard(guard::Header("TOKEN", &token))

user_3884270
Related