How do you make a GET request in Rust?

Question

I noticed that Rust doesn't have a builtin library to deal with HTTP, it only has a net module that deals with raw IP and TCP protocols.

I need to take a &str of the URL, make a HTTP GET request, and if successful return either a String or &str that corresponds to the HTML or JSON or other response in string form.

It would look something like:

use somelib::http;

let response = http::get(&"http://stackoverflow.com");
match response {
    Some(suc) => suc,
    None => panic!
}

Solution 1

Take a look at Hyper.

Sending a GET request is as simple as this.

let client = Client::new();

let res = client.get("http://example.domain").send().unwrap();
assert_eq!(res.status, hyper::Ok);

You can find more examples in the documentation.

Edit: It seems that Hyper got a bit more complicated since they started to use Tokio. Here is updated version.

extern crate futures;
extern crate hyper;
extern crate tokio_core;

use std::io::{self, Write};
use futures::{Future, Stream};
use hyper::Client;
use tokio_core::reactor::Core;


fn main() {
    let mut core = Core::new().unwrap();
    let client = Client::new(&core.handle());

    let uri = "http://httpbin.org/ip".parse().unwrap();
    let work =
        client.get(uri).and_then(|res| {
            println!("Response: {}", res.status());

            res.body().for_each(|chunk| {
                io::stdout()
                    .write_all(&chunk)
                    .map_err(From::from)
            })
        });
    core.run(work).unwrap();
}

And here are the required dependencies.

[dependencies]
futures = "0.1"
hyper = "0.11"
tokio-core = "0.1"

Solution 2

The current best practice for this particular problem is to use the reqwest crate, as specified in the Rust Cookbook. This code is slightly adapted from the cookbook to run standalone:

extern crate reqwest; // 0.9.18

use std::io::Read;

fn run() -> Result<(), Box<dyn std::error::Error>> {
    let mut res = reqwest::get("http://httpbin.org/get")?;
    let mut body = String::new();
    res.read_to_string(&mut body)?;

    println!("Status: {}", res.status());
    println!("Headers:\n{:#?}", res.headers());
    println!("Body:\n{}", body);

    Ok(())
}

As the cookbook mentions, this code will be executed synchronously.

See also:

• How can I perform parallel asynchronous HTTP GET requests with reqwest?

Solution 3

Try to go for reqwest:

extern crate reqwest;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut res = reqwest::get("https://httpbin.org/headers")?;

    // copy the response body directly to stdout
    std::io::copy(&mut res, &mut std::io::stdout())?;

    Ok(())
}

Comments

[Matthieu M.]

This kind of question is off-topic on Stack Overflow, so it likely will be closed. If you haven't found your answer by then, I invite you to check the Rust tag wiki Getting Help section which details other venues for open-ended questions.

[marmistrz]

This no longer works, since hyper::Client::new takes some handle argument.

[Erik Berkun-Drevnig]

Unfortunately reqwest requires OpenSSL so not good if you are doing cross compiling

[Shepmaster]

An answer that suggests reqwest already exists. Please be very clear about what benefit this new answer provides compared to the existing one.

[Luis San Martin]

previous answer doesn't compile this onr does :)

[Shepmaster]

That's why we have the capability of making edits to existing answers. It's been edited.

[Luis San Martin]

great! but since Im a new user I cannot comment on previous answer neither edit it..

[jwh20]

Unfortunately this answer no longer compiles. Please update it or delete it.