flake.nix: The entry point for the configuration.
inventory.nix: Defines the fleet inventory (host types, counts, and device-specific overrides).
users.nix: Defines user accounts, passwords, and package sets.
hosts/: Contains the logic for generating host configurations and hardware-specific types.
sw/: Software modules (Desktop, Kiosk, Python, Neovim, etc.).

Quick Start

Updating the System

The system includes a utility script update-system that handles rebuilding and switching configurations. It automatically detects if it is running on a Surface tablet and offloads the build to a more powerful host if necessary.

To apply changes to the current system:

update-system

This command pulls the latest configuration from GitHub and rebuilds the system.

If your configuration uses external flakes (e.g., via flakeUrl), you may need to allow impure evaluation:

update-system --impure

Manual Rebuilds

If you need to rebuild manually or target a specific host:

# Local build
sudo nixos-rebuild switch --flake .

# Build for a specific host
sudo nixos-rebuild switch --flake .#nix-laptop1

Updating Flake Inputs

To update the lockfile (nixpkgs, home-manager versions, etc.):

nix flake update

Configuration Guide

Adding a New User

Open users.nix.
Add a new entry to modules.users.accounts.
Generate a hashed password using mkpasswd -m sha-512 (requires whois package or similar).
Commit and push.

Assigning Users to Hosts

By default, only root and engr-ugaif are enabled. To enable a specific student user on a specific device:

Open inventory.nix.
Locate the host type (e.g., nix-laptop).
Add or update the devices section for the specific index:

nix-laptop = {
  count = 2;
  devices = {
    "1" = { extraUsers = [ "student_username" ]; };
  };
};

Using External Flakes for User Configuration

Users can manage their own Home Manager configuration in a separate flake repository. To use this:

Open users.nix.
In the user's configuration block, set the flakeUrl option:

hdh20267 = {
  # ... other settings ...
  flakeUrl = "github:hdh20267/dotfiles";
};

The external flake must provide a homeManagerModules.default output. Note that using this feature may require running update-system --impure if the flake is not locked in the system's flake.lock.

Adding a New Host

Open inventory.nix.
Increment the count for the relevant host type.
The new host will be named sequentially (e.g., nix-laptop3).

Development

Python Environment

The system comes with pixi and uv for Python project management. It is recommended to use these tools for project-specific environments rather than installing global Python packages.

pixi init my_project
cd my_project
pixi add pandas numpy