--- title: You Don't Need NixOS date: 2024-07-24 keywords: [nix, nixos, linux] subtitle: _Why you should consider Nix Devshells and Home-Manager rather than NixOS if you want to get into Nix_ --- > You're on vacation and you wish to get some food. You find a restaurant, > Ubuntu — an unusual name, perhaps African — but it's right next to your > hotel. You enjoy the food and, feeling emboldened, you decide to try more > places. You venture further out, trying different restaurants like Popos and > Arch. Sure, each time the accent is a little heavier and harder to understand, > but it's manageable. > > Finally, one day, you venture further than ever before and find a charming > little place called Nixos. Greek, perhaps? No problem, you think. After your > difficulties at Arch’s, this should be a piece of cake. But you quickly > realize not a single person there speaks a word of English, not even Google > Translate can save you. Desperately, you try to order anything, but nothing > comes out right. Humbled, you walk back, cursing the restaurant for your > terrible experience. Many people tend to view [NixOS](https://nixos.org/) as "just another distro", and therefore tend to jump straight from Ubuntu/Arch/whatever into NixOS, only to then immediately start complaining that the learning curve is essentially a great cliff. It has certainly been my own experience, but I will argue that there are better ways to approach it. Nix is definitely not an all-or-nothing. It essentially functions as a swiss army knife that addresses the problem of: > _"software runs on computer A, now make it run the same way on computer B"_ There are different "levels" of Nix: - **Nix as a unix package manager:** Nixpkgs has over 80.000 packages so instead of using pacman, apt or homebrew to get your packages you can use Nix instead. Simply run `nix profile install nixpkgs#cowsay`[^1] to permanently install the cowsay package. This is particularly useful on debian-based systems, as apt has an annoyingly small package set. Think of it like the AUR for Arch, but on any distro - even MacOS! - **Nix as a temporary package manager:** Want to quickly run a package but don't want to pollute your system environment with one-off packages? Write `nix shell nixpkgs#cowsay` to get a shell environment with the package cowsay. Want to just _run_ the binary in the cowsay package? Use `nix run nixpkgs#cowsay`. - **Nix as a build environment:** Ever had a repo or piece of code with poorly documented dependencies? Sometimes there are even hidden undeclared dependencies (package that may be default on Ubuntu but not on Arch!). You can include a Nix flake in your repo with build instructions such that anyone with Nix can run `nix build github:github-account/repo` to build your software. - **Nix for a reproducible dotfile managements:** You can use [Home Manager](https://github.com/nix-community/home-manager) to create a _declarative_, _reproducible_ home environment containing all your dotfile configurations and all your packages. Quickly get all your tools, configured as you want on any unix-system in ~15 minutes. - **NixOS for a reproducible linux system:** You can use Nix to configure your entire system: Declaratively install programs, configure and run services (Syncthing, Plex, whatever), configure user programs (like a tiling window manager), anything you want to do on a linux system, but _declaratively_. Notice, you don't even have to switch out apt, homebrew or pacman/AUR for Nix, nor do you have to manage two package managing states with Nix. You can choose to only use it for temporary package environments (`nix run`/`nix shell`) and temporary developments/build environments (`nix develop`/`nix build`). Starting on a "lower level" of Nix would help out a lot and avoid a lot of the more esoteric issues one might have on the "higher levels", while reaping most of the same benefits. You certainly don't have to do what I did and take the plunge directly on something as complex as NixOS, just to fall down and faceplant the concrete below. ## How I used Nix I started using NixOS after having to migrate my Arch configuration, and finding everything a complete mess. What had I configured? What had I installed? What state did I want to keep? Arch did not give me the proper tools to organize this, and I considered writing a bash script myself that set everything up. It seemed hacky and error-prone though, but then I discovered NixOS and knew that this was exactly the tool I needed! Learning to use NixOS was rough though. I spent a lot of time just getting basic stuff to work, and this was despite coming from Arch. Everything had to be done the "Nix Way", and as I maximized for reproducibility, I ended up playing whack-a-mole with countless of tedious issues. All of it for increasingly diminishing returns. So I ended up abandoning NixOS. The final nail in the coffin was when I got a job and had to build the in-house software on my machine, and none of it were trivial examples, requiring deeper knowledge of packaging. Sure, I could have spun up Ubuntu docker containers as a clutch, but why? The NixOS/Arch way of setting up everything manually became too tedious anyways, and I wanted something that _just worked._ I don't want to try to build a package from a github description just to find out that my "snowflake distro" doesn't support a weird pseudostandard that most of the other distros does. I also don't have time to configure every little thing such as bluetooth modules or wifi, I want to have a starting point that gets me the day-to-day features I need and _then_ configure my tooling around that. So I ended up installing PopOS. ## How I _currently_ use Nix The entirety of my Linux journey was: > Kubuntu → Arch → NixOS → PopOS I had arrived back in the land of statefulness and I found myself longing for just a little of that sweet reproducibility and declarability that I had given up. I then recalled something that I had been researching before; [Home Manager](https://github.com/nix-community/home-manager). I never really got the point from my NixOS point of view, but sitting on PopOS it was a lifesaver. I quickly discovered that I could have a "Just Works™" distro with 80% of the benefits of Nix with 20% of the headaches. I could create a reproducible, declarative toolbox using home manager and let PopOS handle all the boring bells and whistles you'd expect from a modern distro. This unfortunately meant that Nix couldn't handle the system-level stuff that I _do_ want to configure, like tweaking PopOS, setting up docker or routing my traffic through a VPN. Sure, I won't have a 100% reproducibility this way, however I save myself from almost all of the pains I had previously. If anything should fail the "Nix Way" I could easily fall back on statefully installing or configuring whatever program I needed on the fly, so I always had an "escape hatch". I gained the ability to bring my toolbox on any unix[^2] machine with just two commands: ```sh # Install Nix curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | sh -s -- install # Install configuration using flakes for the chosen "$MACHINE" (like "work-laptop") nix run home-manager/master -- switch -b backup --flake .#"$MACHINE" ``` This is great! I can now have my toolbox on my work laptop, home laptop, NAS or even my Steam Deck, no matter the flavor of linux they're running. Here is some of the uses I happily use Nix for today: - As a build-tool geared for reproducibility for various software projects - I use a [Nix flake](https://gist.github.com/rasmus-kirk/c56267f2256a5b1326eefdcb2da33d92) to reproducibly compile pandoc-flavoured markdown into pdf's[^3]. It can also run a script that waits for `$file.md` files to change and then compile it into `$file.pdf`. - I use Home Manager to manage all my dotfiles and user-level packages. - I use NixOS on my Raspberry Pi NAS to self-host various services. - Both my home-manager and NixOS configurations are declared in a single [Nix flake](https://github.com/rasmus-kirk/nix-home-manager). Okay, maybe you _should_ use NixOS. I do, after all, still use it today on my server. In that context it's excellent, I get to have a declarative server environment with top-notch reproducibility, all without using Docker! But just installing it on your main work machine is, in my opinion, not the best way to use NixOS, nor is it the best way to get into Nix. It should be reserved for situations where there's clear benefits or for enthusiasts. If you already use NixOS and you're happy with your choice, I see no reason to change your workflow, but I benefitted from changing mine. Using Nix is software heaven when it works, but as soon as you stray from the "happy path" you quickly find your way to software hell. While I learned a lot from my own journey, and _now_ certainly find myself comfortable using this complicated, messy but altogether wonderful tool, I find that some people new to Nix are tempted to follow the same path that I did, but the "hard way" isn't always best way. So don't use NixOS, _use Nix_. > This article is also available [in raw markdown](./index.md) > Discuss at [Hacker News](https://news.ycombinator.com/item?id=41057688) or [Reddit](https://old.reddit.com/r/NixOS/comments/1eb6tcf/dont_use_nixos/) [^1]: Note that this is using the "new" experimental features: `nix-command` and `flakes`. [^2]: If I ran MacOS then not _all_ packages will be available, as the program itself needs to also target Darwin, but you get the point. [^3]: On that same note, I am using Nix and pandoc-flavored markdown to build this very site!