Machine Management

These notes are still a work-in-progress and are currently largely for my personal use only.

Home-Manager Example

Install Nix standalone:

curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | sh -s -- install

Set proper Nix settings in /etc/nix/nix.conf:

substituters = https://cache.nixos.org/ https://github-public.cachix.org
trusted-public-keys = cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY= github-public.cachix.org-1:xofQDaQZRkCqt+4FMyXS5D6RNenGcWwnpAXRXJ2Y5kc=
narinfo-cache-positive-ttl = 0
narinfo-cache-negative-ttl = 0
experimental-features = nix-command flakes auto-allocate-uids

Add these Nix channels via nix-channel --add URL NAME:

$ nix-channel --list
home-manager https://github.com/nix-community/home-manager/archive/release-25.05.tar.gz
nixpkgs https://nixos.org/channels/nixos-25.05

Install home-manager: https://nix-community.github.io/home-manager/index.xhtml#sec-install-standalone

Example home.nix file for personal use:

{ config, pkgs, lib, ... }:
let
  user = "andrew";
  homedir = "/home/${user}";
  anixsrc = ./path/to/sources/anixpkgs/.;
in with import ../dependencies.nix; {
  home.username = user;
  home.homeDirectory = homedir;
  programs.home-manager.enable = true;

  imports = [
    "${anixsrc}/pkgs/nixos/components/opts.nix"
    "${anixsrc}/pkgs/nixos/components/base-pkgs.nix"
    "${anixsrc}/pkgs/nixos/components/base-dev-pkgs.nix"
    "${anixsrc}/pkgs/nixos/components/x86-rec-pkgs.nix"
    "${anixsrc}/pkgs/nixos/components/x86-graphical-pkgs.nix"
    "${anixsrc}/pkgs/nixos/components/x86-graphical-dev-pkgs.nix"
    "${anixsrc}/pkgs/nixos/components/x86-graphical-rec-pkgs.nix"
  ];

  mods.opts.standalone = true;
  mods.opts.homeDir = homedir;
  mods.opts.homeState = "23.05";
  mods.opts.browserExec = "google-chrome-stable";
}

*-rec-* packages can be removed for non-recreational use.

Symlink to ~/.config/home-manager/home.nix.

Corresponding ~/.bashrc:

export NIX_PATH=$HOME/.nix-defexpr/channels:/nix/var/nix/profiles/per-user/root/channels${NIX_PATH:+:$NIX_PATH}
. "$HOME/.nix-profile/etc/profile.d/hm-session-vars.sh"
export NIXPKGS_ALLOW_UNFREE=1
# alias code='codium'
# eval "$(direnv hook bash)"

Build and Deploy a Raspberry Pi NixOS SD Configuration

Since the hardware configuration for the Raspberry Pi is well understood, it makes sense to skip the installer step and deploy a fully-fledged clusure instead.

nixos-generate -f sd-aarch64 --system aarch64-linux -c /path/to/anixpkgs/pkgs/nixos/configurations/config.nix [-I nixpkgs=/path/to/alternative/nixpkgs]

nix-shell -p zstd --run "unzstd -d /nix/store/path/to/image.img.zst"

sudo dd if=/path/to/image.img of=/dev/sdX bs=4096 conv=fsync status=progress

On the Pi, connect to the internet, copy over SSH keys (maybe no need for /root/.ssh/) and then set up the Nix channel(s):

sudo nix-channel --add https://nixos.org/channels/nixos-[NIXOS-VERSION] nixos
sudo nix-channel --update

Note that the nixos-generate step may not have "aarch-ified" the anixpkgs packages (that's something for me to look into) so the anix-upgrade setup steps are especially important:

Make a ~/sources directory
Symlink the configuration file even if it doesn't exist yet
Run anix-upgrade to aarch-ify everything

Build a Raspberry Pi NixOS SD Installer Image

nixos-generate -f sd-aarch64-installer --system aarch64-linux -c /path/to/rpi/config.nix [-I nixpkgs=/path/to/alternative/nixpkgs]

nix-shell -p zstd --run "unzstd -d /nix/store/path/to/image.img.zst"

sudo dd if=/path/to/image.img of=/dev/sdX bs=4096 conv=fsync status=progress

On the Pi, copy over SSH keys (including to /root/.ssh/!) and then set up the Nix channel:

sudo nix-channel --add https://nixos.org/channels/nixos-[NIXOS-VERSION] nixos
sudo nix-channel --update

Installation Instructions on a New Machine

Sources

https://nixos.wiki/wiki/NixOS_Installation_Guide
https://alexherbo2.github.io/wiki/nixos/install-guide/

Note: You can replace steps 1-8 with a kexec kernel load and disk formatting with disko:

Build the installation ISO with NIXPKGS_ALLOW_UNFREE=1 nix-build '<nixpkgs/nixos>' -A config.system.build.isoImage -I nixos-config=pkgs/nixos/installers/personal.nix
Plug in a USB stick large enough to accommodate the image.
Find the right device with lsblk or fdisk -l. Replace /dev/sdX with the proper device (do not use /dev/sdX1 or partitions of the disk; use the whole disk /dev/sdX).
Burn ISO to USB stick with dd if=result/iso/[...]linux.iso of=/dev/sdX bs=4M status=progress conv=fdatasync
On the new machine, one-time boot UEFI into the USB stick on the computer (will need to disable Secure Boot from BIOS first)
Login as the user andrew
Connect to the internet
Within the installer, run sudo anix-install
If everything went well, reboot
On the next reboot, login as user andrew again
Connect to the internet
Run anix-init
Enjoy!

Upgrading NixOS versions with `anixpkgs`

Aside from the source code changes in anixpkgs, ensure that your channels have been updated for the root user:

# e.g., upgrading to 25.05:
home-manager https://github.com/nix-community/home-manager/archive/release-25.05.tar.gz
nixos https://nixos.org/channels/nixos-25.05
nixpkgs https://nixos.org/channels/nixos-25.05

sudo nix-channel --update. Then upgrade with

anix-upgrade [source specification] --local --boot

Cloud Syncing

The following mount points are recommended (using rclone to set up):

dropbox:secrets -> rclone copy -> ~/secrets
dropbox:configs-> rclone copy -> ~/configs
dropbox:Games -> rclone copy -> ~/games
box:data -> rclone copy -> ~/data
box:.devrc -> rclone copy -> ~/.devrc
drive:Documents -> rclone copy -> ~/Documents

Build a NixOS ISO Image

TODO (untested); work out hardware configuration portion.

nixos-generate -f iso -c /path/to/personal/configuration.nix [-I nixpkgs=/path/to/alternative/nixpkgs]

sudo dd if=/path/to/nixos.iso of=/dev/sdX bs=4M conv=fsync status=progress

Keyboard shortcuts

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