WebSockets in Rust

Introduction

Today I'll show you how you can write incredibly fast code in Rust. This is

part one of a tutorial series.

This is an intermediate tutorial, if you are unfamiliar with Rust basics I

would suggest reading the Rust book for free at https://doc.rust-lang.org/stable/book/.

Project Setup

Lets dive right in.

cargo new rust-tutorial
cd rust-tutorial

Let's build our websocket server.

Edit your Cargo.toml and add `ws` to your

[dependencies].

Your Cargo.toml should now look something like this.

[package]
name = "rust-tutorial"
version = "0.1.0"
authors = ["Sean Behan <codebam@riseup.net>"]
edition = "2018"

[dependencies]
ws = "*"

Building the WebSocket Server

Import our libraries.

use ws::listen;

Start a websocket listener.

fn main() {
    listen("127.0.0.1:5000", |out| {
        move |msg: ws::Message| {
            // handle the msg here
        }
    }
}

Handling Messages

We'll respond to recieved messages and just echo them back for now.

Of course you could easily pass this data into any function and use it to

generate a response. In fact the incoming and outgoing data doesn't even have

to be text.

out.send(format!("recieved message: {}", msg.into_text().unwrap())).unwrap();
out.close(ws::CloseCode::Normal)

Testing the Server

If we connect to this now using websocat, which can be installed with `cargo

install websocat`, we can see the server echos back messages that we send to

it.

$ websocat ws://127.0.0.1:5000
hello world
recieved message: hello world

This isn't that interesting. It's cool that we can do all this in just 8 lines

of Rust though!

Next Steps

In the next part of this series I'll show you how to use use

`tokio` to create an asyncronous server so we can

manage simultaneous connections. Stay tuned!