Function Host 

pub fn Host<H: AsRef<str>>(host: H) -> HostGuard

Return predicate that matches if request contains specified Host name.

use ntex::web::{self, guard::Host, App, HttpResponse};

fn main() {
    App::default().service(
        web::resource("/index.html")
            .guard(Host("www.rust-lang.org"))
            .to(async || { HttpResponse::MethodNotAllowed() })
    );
}