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Sputnik

This library extends the types from the http crate:

  • extends http::request::Parts with query parameter deserialization & cookie parsing
  • extends http::response::Builder with methods to set cookies and content-types

If you use Hyper and want to deserialize request bodies with Serde you can enable the following feature flags:

  • hyper_body provides a trait to extend hyper::Body with an into_form method for parsing data submitted from HTML forms.
  • hyper_body_json additionaly provides an into_json method

Sputnik does not handle routing because even complex routing can be quite easily implemented with nested match blocks. If you want a more high-level router, you can check out the router crates.

Sputnik encourages you to create your own error enum and implement From conversions for every error type, which you want to short-circuit with the ? operator. This can be easily done with thiserror because Sputnik restricts its error types to the 'static lifetime.

Security Considerations

Protect your application against CSRF by setting SameSite to Lax or Strict for your cookies and checking that the Origin header matches your domain name (especially if you have unauthenticated POST endpoints).

Hyper Example

use hyper::http::request::Parts;
use hyper::http::response::Builder;
use hyper::service::{make_service_fn, service_fn};
use hyper::{Body, Method, Server, StatusCode};
use serde::Deserialize;
use sputnik::hyper_body::{FormError, SputnikBody};
use sputnik::{html_escape, mime, request::SputnikParts, response::SputnikBuilder};
use std::convert::Infallible;

type Response = hyper::Response<Body>;

#[derive(thiserror::Error, Debug)]
enum Error {
    #[error("page not found")]
    NotFound(String),
    #[error("{0}")]
    FormError(#[from] FormError),
}

fn render_error(err: Error) -> (StatusCode, String) {
    match err {
        Error::NotFound(msg) => (StatusCode::NOT_FOUND, msg),
        Error::FormError(err) => (StatusCode::BAD_REQUEST, err.to_string()),
    }
}

async fn route(req: &mut Parts, body: Body) -> Result<Response, Error> {
    match (&req.method, req.uri.path()) {
        (&Method::GET, "/form") => Ok(get_form(req)),
        (&Method::POST, "/form") => post_form(req, body).await,
        _ => return Err(Error::NotFound("page not found".to_owned())),
    }
}

fn get_form(_req: &mut Parts) -> Response {
    Builder::new()
        .content_type(mime::TEXT_HTML)
        .body("<form method=post><input name=text> <button>Submit</button></form>".into())
        .unwrap()
}

#[derive(Deserialize)]
struct FormData {
    text: String,
}

async fn post_form(_req: &mut Parts, body: Body) -> Result<Response, Error> {
    let FormData { text } = body.into_form().await?;
    Ok(Builder::new()
        .content_type(mime::TEXT_HTML)
        .body(format!("hello <em>{}</em>", html_escape(text)).into())
        .unwrap())
}

async fn service(
    req: hyper::Request<hyper::Body>,
) -> Result<hyper::Response<hyper::Body>, Infallible> {
    let (mut parts, body) = req.into_parts();
    match route(&mut parts, body).await {
        Ok(mut res) => {
            for (k, v) in parts.response_headers().iter() {
                res.headers_mut().append(k, v.clone());
            }
            Ok(res)
        }
        Err(err) => {
            let (code, message) = render_error(err);
            // you can easily wrap or log errors here
            Ok(hyper::Response::builder()
                .status(code)
                .body(message.into())
                .unwrap())
        }
    }
}

#[tokio::main]
async fn main() {
    let service = make_service_fn(move |_| async move {
        Ok::<_, hyper::Error>(service_fn(move |req| service(req)))
    });

    let addr = ([127, 0, 0, 1], 8000).into();
    let server = Server::bind(&addr).serve(service);
    println!("Listening on http://{}", addr);
    server.await;
}