My avatar logoInom Turdikulov

3 min read

NixOS

NixOS is a Linux distribution based on the Nix package manager and build system. It supports reproducible and declarative system-wide configuration management as well as atomic upgrades and rollbacks, although it can additionally support imperative package and user management. In NixOS, all components of the distribution — including the kernel, installed packages and system configuration files — are built by Nix from pure functions called Nix expressions.
— NixOS Wiki

NixOS is my current favorite Linux distribution. I like their features and trying to use it everywhere where it’s possible. Arch Linux is also good (minimal), but I like the NixOS approach more.

Features

  • Declarative configuration model (Nix language, global configuration file).
  • Reliable and atomic upgrades (same result on different machines, atomic. upgrades which are resistant to power failures).
  • Rollbacks (boot menu with previous configurations).
  • Reproducible system configurations (easily clone system across many machines).
  • Source-based model with binary cache (flexible build configuration, change package options)
  • Consistency (rebuild all dependencies when core packages are updated).
  • Multi-user package management (users can install packages without root).

  • 80,000 official packages (Nixpkgs), special packages with easily configurable options (NixOS options, > 10000 options).

  • Documentation and community (Guides and Tutorials, NixOS wiki, Discourse, Matrix, GitHub).

Cleanup old generations

Native nix commands:

nix-env --list-generations
 
nix-collect-garbage --delete-older-than 30d
# or nix-collect-garbage --delete-old
 
# recommeneded to sometimes run as sudo to collect additional garbage
# in my case it's very actual, since I use a lot system packages
sudo nix-collect-garbage --delete-older-than 30d
# or sudo nix-collect-garbage --delete-old
 
# After the garbage collection, you can run the following command to remove
# boot entries that are no longer valid:
sudo nixos-rebuild switch

TODO: own hey utility?

hey gc; sudo hey gc
sudo /run/current-system/bin/switch-to-configuration boot

Get revision/hash for fetchFromGitHub/fetchit

For example this repo: https://github.com/cli/cli

# SHA256
nix-shell -p nix-prefetch-git jq --run \
  "nix hash to-sri sha256:\$(nix-prefetch-git --url https://github.com/cli/cli --quiet --rev v2.20.2 | jq -r '.sha256')"
 
# sha256
nix-shell -p nix-prefetch-git jq --run \
  "nix hash to-sri sha256:\$(nix-prefetch-git --url https://github.com/iturdikulov/dwm-flexipatch --quiet | jq -r '.sha256')"
 
# REV
nix-shell -p nix-prefetch-git jq --run "nix-prefetch-git --url https://github.com/cli/cli --quiet --rev v2.20.2 | jq -r '.rev'"
 
# HASH
nix-shell -p nix-prefetch-git jq --run "nix-prefetch-git --url https://github.com/iturdikulov/dwm-flexipatch --quiet | jq -r '.hash'"

LD_LIBRARY_PATH issues

This can happen when importing python libraries: Solution: add ${stdenv.cc.cc.lib}/lib/libstdc++.so.6 to the LD_LIBRARY_PATH.

A sample shell.nix:

{ pkgs ? (import <nixpkgs> {}).pkgs }:
with pkgs;
mkShell {
  buildInputs = [
    python3Packages.virtualenv # run virtualenv .
    python3Packages.pyqt5 # avoid installing via pip
    python3Packages.pyusb # fixes the pyusb 'No backend available' when installed directly via pip
  ];
  shellHook = ''
    # fixes libstdc++ issues and libgl.so issues
    LD_LIBRARY_PATH=${stdenv.cc.cc.lib}/lib/:/run/opengl-driver/lib/
    # fixes xcb issues :
    QT_PLUGIN_PATH=${qt5.qtbase}/${qt5.qtbase.qtPluginPrefix}
  '';
}

PCI passthrough

TODO:

  • linux kernel flake + le9ec
  • test Plasma/Wayland
  • pipewire low-latency + rtkit

Configurations

Backlinks

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