Why everyone is switching to NixOS ?

★ Ｌ０Ｗｉｇｈ@sh.itjust.works to Linux@lemmy.ml – 15 points –

Hi everyone!

I saw that NixOS is getting popularity recently. I really have no idea why and how this OS works. Can you guys help me understanding all of this ?

Thanks !

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I'm really not sure of where this would be anymore usefull than a simple bash script to install all packages you need since it doesn't do configs and that rollbacks are supported by some filesystems already. Also Having version specific dependencies is already a thing for flatpacks and such

A simple bash script is not reproducible or deterministic. Also a filesystem rollback is not the same as NixOS's generation based rollback.

Also, NixOS doesn't just install packages, all system configuration is done declaratively, which would be a very bad idea to do via a bash script.

I have to check a little harder on what it does since I saw in a vid that you still needed to add your own if statement to get it working I assumed a simple

pacman -Qk xorg-xrtrop 2> /dev/null && sudo pacman --noconfirm -S package1 package2 package3 || echo 'I aint got no x, idiot'

would do the job as well

I'd recommend reading some more; especially w.r.t. imperative vs. declarative.

In NixOS, you'd do something like this:

{ config, ... }:

{
  environment.systemPackages = if config.services.xserver.enabled then [
    package1
    package2
    package3
  ] else [
    # You could optionally make headless packages available here
  ];
}

You don't need to understand the exact semantics here but you can look at it like JSON but with functions. This is not a "program", the end-result is just data. You're not modifying some stateful system state with new state from an uncontrolled source (i.e. the Arch repos) but rather just "outputting" a different dataset.
NixOS then builds a concrete system out of this pure data specification. In this concrete system, those packages' executables are available in the "global" PATH.

You say "I want a system where x y z are installed" and it does it for you in a standardised manner. With the bash script, you explicitly tell it each step ("install x; install y; install z"). This pure data nature is what's meant by declarative.
This distinction rules out whole classes of issues you simply cannot run into with NixOS.

Another aspect is that, as long as you use the same revision of Nixpkgs and the same config file, you can re-create the exact same system (almost bit-for-bit). If you were to run your bash script in a year's time however, you'd get an entirely different system with totally different revisions of software and therefore possibly entirely different behaviour.
This is what's meant by reproducibility.

You can achieve some of the same things NixOS does using imperative tools but nowhere near the same quality.

Part of the purpose of NixOS is providing a means to build a reproducible environment that's easy to configure, migrate, and rollout. You can absolutely handle configuration of many different programs using either flakes or the native modules provided by nix. You can customize your entire system from firewall entries, to users and their shells, to the kernel itself and the kernel modules you'd want it to load, all in a single file or multiple files. If you want to try doing all those things in bash scripts, good luck and please share your experiences but don't expect it to be as easy as the Nix ecosystem.

so it does handle more than just conditional packages like the other zealots make it sound like

Wayyy more. You can move all of your dotfiles to Nix config. And deploy it with Nix based infrastructure.