As an exercise to learn some new technologies, I made a to-do MVP app. These are the technologies I wanted to check out:

• Go - a modern and friendly-to-use programming language
• Atlas - a tool to declaratively manage your database schemas
• Nix and Nix flakes - A reproducible package manager

In this post I give them each a mini-review.

Architecture

The app consists of a PostgreSQL database inside a container whose schema is managed using Atlas. The CLI app is written in Go with huh for the UI and pq to interact with the database. Nix is used as a package manager, for the developer environment and as a container image builder. You can view the code here.

Go

Go is wonderful language. It gets out of the way and allows you to solve the problem at hand.

I give Go 5 stars! ⭐⭐⭐⭐⭐

Atlas

While SQL technically follows a declarative paradigm, altering table schemas breaks this property. Atlas attempts to tackle this issue by keeping the current state of your schema as either hcl or SQL code. hcl is a configuration language that’s easy on the eyes.

table "users" {
  schema = schema.example
  column "id" {
    null = false
    type = int
  }
  column "name" {
    null = true
    type = varchar(100)
  }
  primary_key {
    columns = [column.id]
  }
}

If you want a new column or table, you simply append it to the snippet above. Simple as that. Changing the name of a column will cause the old column to be dropped and a new one created, removing all the data in the process. You first need to perform an ALTER COLUMN... before applying the schema using Atlas, which sadly takes the declarative magic away.

Atlas receives 4 stars for now, although I’m sure more pain points will become apparent when it’s used to perform migration in production environments. ⭐⭐⭐⭐

Nix

The promise of Nix is the ability to build and run our code far into the future. No more build errors or missing dependencies. While it does achieve this, a lot is left to be desired. The entire system is quite complex, having a steep learning curve and documentation that’s a bit lacking in some places. Despite this, it’s still a tool I hope to use more often in the future. No longer having to install different package managers or build from source simply to get the correct version of a package is bliss.

The closest thing I’ve seen that simply delivers the packages you want is pkgx. And it does this with the simplicity that I wish Nix had. It however has its own quirks and its package repository is not that sizable for the time being.

The process of making a Go package with Nix Flakes is pretty messy. The documentation on it is again quite short. First, you have to set the vendorHash to null and run go mod vendor. But also don’t forget to commit everything or Nix won’t be able to see all the files resulting in cryptic errors. When you’re ready to release, you can obtain a vendorHash by setting it to lib.fakeHash and removing the vendor folder. And don’t forget to commit!

Overall Nix and Flakes, while hard to learn, promise the “It just works” dream. I can’t help but feel like every package manager should be more declarative in the future. Therefore it receives a solid 4 stars. ⭐⭐⭐⭐