NixOS

For each machine, there is a top-level directory, e.g. yodaTab.

Build and Switch

• https://nixos.wiki/wiki/Nixos-rebuild

Directly change to new config and make it default:

sudo nixos-rebuild -I nixos-config=yodaTab/configuration.nix switch

System updates

• https://superuser.com/a/1604695

sudo nix-channel --update

# The -s param does currently not work for both, .nix and .json file.
# Workaround: https://github.com/nmattia/niv/pull/133#issuecomment-703322261
#
#niv --sources-file=yodaTab/nix/sources.json update
#
(cd yodaTab && niv update)

Then run nixos-rebuild switch, see above.

Garbage Collection

• https://nixos.org/manual/nix/stable/package-management/garbage-collection.html
• https://discourse.nixos.org/t/why-doesnt-nix-collect-garbage-remove-old-generations-from-efi-menu/17592/4

For all profiles:

sudo nix-collect-garbage --delete-older-than 14d

Remove old generations from EFI:

sudo /run/current-system/bin/switch-to-configuration boot

Install Home Manager with niv

niv:

Easy dependency management for Nix projects.

Nix is a very powerful tool for building code and setting up environments. niv complements it by making it easy to describe and update remote dependencies (URLs, GitHub repos, etc). It is a simple, practical alternative to Nix flakes.

https://github.com/nmattia/niv

Niv is an easy dependency management for Nix projects with package pinning.

https://github.com/mikeroyal/NixOS-Guide

Home Manager:

[Home Manager] allows declarative configuration of user specific (non-global) packages and dotfiles.

To avoid breaking users' configurations, Home Manager is released in branches corresponding to NixOS releases ( e.g. release-23.05).

Home Manager provides both the channel-based setup and the flake-based one.

https://github.com/nix-community/home-manager

Check your channel:

sudo nix-channel --list
#=> nixos https://nixos.org/channels/nixos-23.05

Use the corresponding branch:

(cd yodaTab && niv add nix-community/home-manager -n home-manager -b release-23.05)

disko and nixos-anywhere

• Introductory presentation: https://pad.lassul.us/cccamp-workshop
• disko: https://github.com/nix-community/disko
• nixos-anywhere: https://github.com/numtide/nixos-anywhere/

# TODO (!)

BTRFS Swap file

• https://nixos.wiki/wiki/Btrfs#Swap_file
• https://wiki.archlinux.org/title/btrfs#Swap_file

Summary:

• Create subvolume @swap directly below top-level subvolume.
• Mount at /swap
• Create swapfile: sudo btrfs filesystem mkswapfile --size 8g --uuid clear /swap/swapfile
• Regenerate hardware-configuration: sudo nixos-generate-config --dir yodaTab
• Add swapDevices = [ { device = "/swap/swapfile"; } ]; to hardware configuration and run nixos-rebuild switch (see above).

Automount Encrypted Drive

• Generate and add keyfile to LUKS device
• luksOpen and mount drive, e.g. to /mnt/data1
• Re-generate hardware configuration:

sudo nixos-generate-config --dir yodaTab

GNOME extensions

• https://github.com/nix-community/home-manager/issues/284#issuecomment-531384656
• https://github.com/nix-community/home-manager/issues/284#issuecomment-1321199263
  • Search for packaged extensions: https://search.nixos.org/packages?channel=23.05&from=0&size=50&sort=relevance&type=packages&query=gnomeExtensions
  • One has to re-login after changes: https://github.com/nix-community/home-manager/issues/284#issuecomment-1328269433

# TODO

Run an AppImage

• https://nixos.wiki/wiki/Appimage

# Note how your shell prefix changes.
nix-shell --packages appimage-run

# Inside the shell, you can run an AppImage:
appimage-run ~/Downloads/ubports-installer_0.10.0_linux_x86_64.AppImage

General Notes

• There is controversy about flakes, rather use channels (e.g. with niv)

Nix Pills

• https://nixos.org/guides/nix-pills/pr01

It provides a tutorial introduction into the Nix package manager and Nixpkgs package collection, in the form of short chapters called 'pills'.

Thesis

There are two (?) theses about Nix. One is https://edolstra.github.io/pubs/phd-thesis.pdf

Search for packages

• https://search.nixos.org/packages?channel=23.05

Search for options

• https://search.nixos.org/options?channel=23.05
  • Or man configuration.nix
• https://mipmip.github.io/home-manager-option-search
  • Or man home-configuration.nix

Search wich package owns a file

# Note how your shell prefix changes.
nix-shell --packages nix-index

# Inside the shell:

# Either build the index manually (requires >8GB RAM)
nix-index
# Or download weekly build:
mkdir -p ~/.cache/nix-index/ && wget -q -N https://github.com/nix-community/nix-index-database/releases/latest/download/index-x86_64-linux -O ~/.cache/nix-index/files

# Then search for a file
nix-locate -w '/bash'

References

Some references to websites that helped me create this repository:

• https://github.com/Misterio77/nix-starter-configs
• https://github.com/mikeroyal/NixOS-Guide#getting-started

TODOs

• FDE remote SSH unlock: https://nixos.wiki/wiki/Remote_LUKS_Unlocking
• Impermanence, opt-in to persistence: https://github.com/Misterio77/nix-starter-configs/tree/main#try-opt-in-persistance
• nix-shell / lorri
  • https://ghedam.at/15978/an-introduction-to-nix-shell
    • docker-compose.yml for services and nix-shell to run the code