Module tower_http::follow_redirect

This is supported on crate feature follow-redirect only.

Middleware for following redirections.

Overview

The FollowRedirect middleware retries requests with the inner Service to follow HTTP redirections.

The middleware tries to clone the original Request when making a redirected request. However, since Extensions are !Clone, any extensions set by outer middleware will be discarded. Also, the request body cannot always be cloned. When the original body is known to be empty by Body::size_hint, the middleware uses Default implementation of the body type to create a new request body. If you know that the body can be cloned in some way, you can tell the middleware to clone it by configuring a policy.

Examples

Basic usage

use http::{Request, Response};
use hyper::Body;
use tower::{Service, ServiceBuilder, ServiceExt};
use tower_http::follow_redirect::{FollowRedirectLayer, RequestUri};

let mut client = ServiceBuilder::new()
    .layer(FollowRedirectLayer::new())
    .service(http_client);

let request = Request::builder()
    .uri("https://rust-lang.org/")
    .body(Body::empty())
    .unwrap();

let response = client.ready().await?.call(request).await?;
// Get the final request URI.
assert_eq!(response.extensions().get::<RequestUri>().unwrap().0, "https://www.rust-lang.org/");

Customizing the Policy

You can use a Policy value to customize how the middleware handles redirections.

use http::{Request, Response};
use hyper::Body;
use tower::{Service, ServiceBuilder, ServiceExt};
use tower_http::follow_redirect::{
    policy::{self, PolicyExt},
    FollowRedirectLayer,
};

#[derive(Debug)]
enum MyError {
    Hyper(hyper::Error),
    TooManyRedirects,
}

let policy = policy::Limited::new(10) // Set the maximum number of redirections to 10.
    // Return an error when the limit was reached.
    .or::<_, (), _>(policy::redirect_fn(|_| Err(MyError::TooManyRedirects)))
    // Do not follow cross-origin redirections, and return the redirection responses as-is.
    .and::<_, (), _>(policy::SameOrigin::new());

let mut client = ServiceBuilder::new()
    .layer(FollowRedirectLayer::with_policy(policy))
    .map_err(MyError::Hyper)
    .service(http_client);

// ...

Modules

policy

Tools for customizing the behavior of a FollowRedirect middleware.

Structs

FollowRedirect	Middleware that retries requests with a Service to follow redirection responses.
FollowRedirectLayer	Layer for retrying requests with a Service to follow redirection responses.
RequestUri	Response Extensions value that represents the effective request URI of a response returned by a FollowRedirect middleware.
ResponseFuture	Response future for FollowRedirect.