Hello Rust!

This is an example app demonstrating how to deploy a Rust program on Fly.io

Structure

App

Warp-based "hello world" app, as simple as it can get.

Binding to all addresses

Noticed this line?

    warp::serve(routes)
        // ipv6 + ipv6 any addr
        .run(([0, 0, 0, 0, 0, 0, 0, 0], 8080))
        .await;

This listens to all addresses on both IPv4 and IPv6, on port 8080. It's important to do this because your app would otherwise need to know about the 172.19.0.0/16 IP it should bind to specifically. Binding to IPv6 is not required, but is likely a good idea going forward.

fly.toml

A fairly standard fly.toml configuration, except for the cmd override:

[experimental]
cmd = "./hello" # should be the name of the binary you want to run

Dockerfile

The most efficient way to create a Docker image for a Rust app is a simple Dockerfile.

Our Dockerfile is heavily commented, but here's a short rundown:

Copy Cargo.{toml,lock} and build dependencies
Copy whole project and cargo install it

.dockerignore

You definitely want to ignore /target since this can get pretty hefty, adding to the build context's size, and slow down builds significantly.

Deploy

fly launch

fly-apps / hello-rust