Nix(OS) Configurations

This repository contains configurations for various programs & Nix(OS). This Nix(OS) section of this repository is located in the nixos directory.

Pre Requisites

Install Home Manager CLI

nix-channel --add https://github.com/nix-community/home-manager/archive/master.tar.gz home-manager
nix-channel --update
nix-shell '<home-manager>' -A install

Using Docker Compose to Check Configs

docker compose run --remove-orphans check

File Structure

nixos/hosts

• The hosts contains the configuration.nix files for each of my computers that runs NixOS.
• Each host is assigned a separate folder.
• The configuration that flake.nix uses is decided by the hostname of the system.
• The creation of users is managed by the configuration.nix but all the user related configuration is handled by home-manager. The common link between the created user and configured user is just the username. This means that users with the same name on all systems will be configured the same way if home-manager is used configure the user.

users

• The users directory is the home-manager section of the configuration.
• Each username has a username.nix file that contains user level home-manager managed configurations.
• The users/shared directory contains modules that are shared across multiple users.

secrets

• This directory contains a secrets.json file (encrypted using git crypt). which should contain a JSON object.
• This JSON object is made available to both the home-manager user configurations in users & system configurations in hosts via the secrets function parameter.

flake.nix

This is the entry point for both the home-manager & NixOS.

NixOS

Modifications

After making any changes in the hosts directory, you can install the changes to the current host configuration into NixOS using the following command on the host.

sudo nixos-rebuild switch --flake .

# OR

rake nix:os:install

Formatting

nix fmt

Upgrading

Since we are using a flake.lock file, we need to update the flake using the command below and rebuild the system as normal.

# TO BE RUN FROM THE ROOT OF THIS CLONED REPOSITORY
nix flake update

# OR

rake nix:flake:update

Home-Manager

Modifications

Any modifications to the nixos/users directory can be installed using this home-manager command

home-manager switch --flake './nixos' -j 4 --impure

# OR 

rake nix:home:install

• --impure flag is required because nixGL uses builtins.currentTime as an impure parameter to force the rebuild on each access.