content: add first shitty draft of nixos post

src/posts/2024-08-10-i-wasted-half-my-summer-on-nixos.md

@@ -0,0 +1,121 @@
+---
+author: "Youwen Wu"
+authorTwitter: "@youwen"
+desc: "some thoughts"
+image: "./images/gradient-ascent.jpg"
+keywords: "haskell, blog, functional programming"
+lang: "en"
+title: "i wasted half my summer setting up NixOS"
+updated: "2024-05-25T12:00:00Z"
+---
+
+Here's what I've been up to since the start of the summer: after a month long
+fender-bender with functional programming and the mathematicians up in the ivory
+tower at Haskell Industries™, I spent a month setting up an esoteric Linux
+distribution likely conceived of by bitter Haskell theorists who were fed up
+with the fact that the real world and computers were stateful and wanted to do
+something about it.
+
+This distribution, of course, was NixOS. And I guess you could consider the
+following either a case study or an autopsy of a real user of it.
+
+## what even is NixOS?
+
+It's somewhat difficult to explain the concept of Nix/NixOS to even the average
+Linux user. It's simple, really: Nix is a tool described and developed by Eelco
+Dolstra in his Ph.D thesis, _The Purely Functional Software Deployment Model_,
+where he shows how to implement a tool which atomically resolves dependencies
+through the use of derivations, which are pure functions that encode the build
+process of a package...
+
+The majority of readers have likely left at this point immediately after the
+mention of _Ph.D thesis_. If you are still reading, I presume that the previous
+word salad either made some semblance of sense to you, or you're masochistic
+enough that you're willing to sit through a seminar about esoteric and
+overcomplicated concepts - both great qualities for a Nix user to have.
+
+First of all, if you've never heard of Nix, it may be hard to get a straight
+answer for what it is. And that's because it's many different things. Nix, by
+itself, is a package manager which can be installed on any distro that can also
+help create _reproducible_ environments declaratively. This means that you can
+use it to install packages like a regular package manager:
+
+```bash
+# Arch Linux
+$ pacman -S neofetch
+
+# Nix
+$ nix-env -i neofetch
+```
+
+Or, you can define a shell environment in a `nix` file, and it will fetch all
+the required packages and throw you into an environment with them available,
+_without polluting your global PATH_. This is powerful for specifying all the
+packages needed to develop on a project, with their exact version, and have them
+all automatically available to developers without affecting their system
+installations. This feature of Nix is used to manage
+[this blog](https://github.com/youwen5/blog), in fact. You can also define build
+scripts in this file, so Nix can also be used as a simple build tool, like
+**Make**.
+
+There are many more features of Nix, but I don't intend for this post to be a
+full introduction to Nix or even a simple tutorial. There's enough of that over
+at [nix.dev](https://nix.dev/) and the wonderful
+[NixOS and Flakes Book](https://nixos-and-flakes.thiscute.world/).
+
+But the defining factor of Nix, which makes it different from other tools like
+`direnv` which do similar things, is its **reproducible builds**. Through a
+concept called "derivations", Nix encodes _exactly_ how a package is built, down
+to the patches and compiler options. It also requires the exact dependencies be
+specified - Nix cannot access system-wide programs while building.
+
+This means that the slightest change to a build process will result in a
+different derivation. And this means that, in theory, if a derivation builds on
+one machine, it should also build on every other machine, exactly the same way.
+It solves the "it works on my machine issue", without any virtualisation a la
+Docker.
+
+### NixOS is a different kind of operating system
+
+Most Linux distributions are really just some set of base software and a package
+manager (usually the defining aspect for power users). NixOS is a Linux
+distribution that uses Nix as its principle package manager. But it's also more
+than that.
+
+The principle issue I have with Arch (and every other distro) is that
+fundamentally, it pretty much does what every distro after Slackware has tried
+to do: provide the user with a base working system and a package manager that
+can efficiently install and manage software. Arch just happens to contain a
+pretty decent package manager with massive repositories and a minimal set of
+base software, which aligns exactly with the goal of \*nix enthusiasts.
+
+When I say that NixOS is a new kind of operating system, I don't mean that it
+has a novel kernel, or even a new init system or completely new userspace
+components. At the end of the day, you'll be running the same Linux applications
+on the same Linux kernel you know. Strictly speaking, it is just another set of
+base packages running on the Linux kernel, with the Nix package manager.
+
+What makes NixOS different is its completely new approach to system management
+and configuration from everything else that has been tried in the last two
+decades [^1]. In a traditional distribution, you are provided with a tool to
+fetch packages and install them into your system. That's all well and good, but
+what about the rest? How do you manage the rest of your system configuration?
+How do you manage already installed packages, like updating or removing them
+cleanly? How do you deal with a system in a broken state, or with mismatching
+dependency versions (the so-called dependency hell)? As a user, how can you set
+up a system from scratch automatically with all the little things configured
+like you want?
+
+Nix and NixOS claims to solve all of these issues and more. Let's see if it
+lives up to its promises.
+
+### system configuration
+
+Most critical system components need some form of configuration, usually by text
+file. Most distributions provide no built-in way to manage these. Also,
+third-party solutions are mostly unwieldy.
+
+[^1]:
+    Well, there's the _other distro_: [GNU Guix](https://guix.gnu.org/)
+    (pronounced _geeks_), which is a fork of Nix released in 2019 that aims to
+    achieve similar goals.