Wait wait wait, so we're not talking about nix yet?

Well, no! The service we have is pretty simple, and I want to complicate things a bit, to show how things would work in both the Dockerfile and the nix scenario.

And because I don't like contrived examples, we're going to do something somewhat real-world: we're going to geo-locate visitors, and track how many visits we get from each country.

Now that our service is production-ready, it's time to deploy it somewhere.

There's a lot of ways to approach this: what we are going to do, though, is build a docker image. Or, I should say, an OCI image.

This is still a series about Nix, but again: because the best way to see the benefits of Nix is to do it without Nix first, we'll use only Docker's tooling to build the image.

Our catscii program does everything we want it to do, except that it's a command-line application rather than a web server. Let's fix that.

The documentation for the axum crate tells us how to make a basic web server, and we honestly don't need much more than that.

So let's add axum:

amos@miles:~/catscii$ cargo add axum@0.6
    Updating crates.io index
      Adding axum =0.6 to dependencies.
             Features:
             + form
             + http1
             + json
             + matched-path
             + original-uri
             + query
             + tokio
             + tower-log
             - __private_docs
             - headers
             - http2
             - macros
             - multipart
             - w

Now that our development environment is all set up, let's make something useful!

From a VS Code window connected to our VM (as we just set up), let's make a new Rust project:

amos@miles:~$ cargo new catscii
     Created binary (application) `catscii` package

And open it in a new VSCode window:

amos@miles:~$ code catscii

I often give bits and pieces of advice on how to build Rust stuff the comfy way. But it can be hard to see how everything comes together, especially when it comes to, say, deploying a web service in production.

So, let's start from the very beginning (setting up a Linux VM), and march together towards the objective: a production-grade Rust web service, built with Nix.

Some bugs are merely fun. Others are simply delicious!

Today's pick is the latter.

(It may be tempting to skip that section, but reproducing an issue is an important part of figuring it out, so.)

I've never used Emacs before, so let's install it. I do most of my computing on an era-appropriate Ubuntu, today it's Ubuntu 22.10, so I just need to:

This time around, we're porting a solution from C++ to Rust and seeing how it feels, how it performs, and what we can learn about both languages by doing that.

See Day 17 for the rationale re: porting solutions rather than writing my own from scratch. TL;DR is: it's better than nothing, and we can still focus about learning Rust rather than spending entire days fighting off-by-one errors.