I enjoy building things with a language in order to learn it, and I’m sure you do too. So, let’s build a simple server with Rust and Axum.

What is Axum?

Axum is a web framework built on top of hyper and tower. It is designed to be both easy to use and performant.

Setting Up Your Project

First, you’ll need to create a new Rust project. You can do this by running the following command:

cargo new simple_server

Next, you’ll need to add the axum and tokio dependencies to your Cargo.toml file:

[dependencies]
axum = "0.7.5"
tokio = { version = "1", features = ["full"] }

Creating Your Server

Now that you have your project set up, you can start building your server. Open up a file called main.rs in the src directory of your project and add the following code:

use axum::{routing::get, Router};

#[tokio::main]
async fn main() {
    let app = Router::new().route("/", get(|| async { "Hello, World!" }));

    let listener = tokio::net::TcpListener::bind("0.0.0.0:4000").await.unwrap();
    axum::serve(listener, app).await.unwrap();
}

Awesome, you’ve just created a simple server that listens on port 4000 and responds with Hello, World! when you navigate to http://localhost:4000.

Let’s break it down Now

We start by importing the necessary modules from the axum crate.

use axum::{routing::get, Router};

We define a main function that is marked as async using the #[tokio::main] attribute.

#[tokio::main]
async fn main() {

We create a new Router using the Router::new() function and define a single route that responds with Hello, World! when the root path is accessed.

let app = Router::new().route("/", get(|| async { "Hello, World!" }));

We bind the server to localhost:4000 using tokio::net::TcpListener::bind("0.0.0.0:4000").await.unwrap().

let listener = tokio::net::TcpListener::bind("0.0.0.0:4000").await.unwrap();

Finally, we serve the app using axum::serve(listener, app).await.unwrap().

axum::serve(listener, app).await.unwrap();

Running Your Server

To run your server, you can use the following command:

cargo run

You should see the following output:

   Compiling simple_server v0.1.0 (/Users/elliotforbes/simple_server)
    Finished dev [unoptimized + debuginfo] target(s) in 0.23s
     Running `target/debug/simple_server`

Now, navigate to http://localhost:4000 in your browser, and you should see Hello, World! displayed on the page.