Creating a hyper service in a match expression

[mihaigalos]

Hi, I'm trying to do the following:

let service = match args.is_present("secure") {
        true => Box::new(make_service_fn(|_| async {
            Ok::<_, hyper::Error>(service_fn(service_secure))
        })),
        false => Box::new(make_service_fn(|_| async {
            Ok::<_, hyper::Error>(service_fn(service))
        })),
    };

This doesn't compile:

103 |       let service = match args.is_present("secure") {
    |                     ------------------------------- `match` arms have incompatible types
104 |           true => Box::new(make_service_fn(|_| async {
    |  _________________-
105 | |             Ok::<_, hyper::Error>(service_fn(service_secure))
106 | |         })),
    | |___________- this is found to be of type `Box<hyper::service::make::MakeServiceFn<[closure@src/main.rs:104:42: 106:10]>>`
107 |           false => Box::new(make_service_fn(|_| async {
    |  __________________^
108 | |             Ok::<_, hyper::Error>(service_fn(service))
109 | |         })),
    | |___________^ expected closure, found a different closure

Any way around this?

[olix0r]

You probably want to use tower::util::BoxService. If you really only want to vary the service definition i'd probably move the match into the makeservice, too:

let is_secure = args.is_present("secure");
let service =  make_service_fn(move |_| async move {
    let svc = if is_secure {
        BoxService::new(service_fn(call_secure))
    } else {
        BoxService::new(service_fn(call_insecure))
    };
    Ok::<_, hyper::Error>(svc)
});

If you don't want to move the comparison into make_service, you'll need both the make_service_fn and service_fn to be wrapped in BoxService.

Also note there's a BoxCloneService if the service needs to implement clone.

[mihaigalos]

Thank you, works!