Nix Configuration

Overview

This is my NixOS + MacOS Nix shared configuration. It is based on merging two configurations:

• nixos-config: This facilitates sharing packages between computers, I strongly recommend it as a base configuration to use as a base.
• neusis: This is the config used for multiple servers in at the Broad Institute’s Imaging Platform. I use it to support multiple users on NixOS alongside Darwin.

Set up

I haven’t set it up from scratch in a new set of computers, but I will update it once I do.

Usage

Update home (Linux and Darwin)

The standalone home-manager entrypoint works the same on both platforms. It re-activates the user-level bits (dotfiles, user packages, fish/git/atuin config, user services / launchd agents) without touching system defaults, Homebrew, or /etc/nix/nix.custom.conf, and does not need sudo.

home-manager switch --flake .#your-username@your-hostname

Available entrypoints:

• amunoz@moby (Linux)
• alan@darwin001 (Darwin)
• amunozgo@darwin002 (Darwin)

System rebuild

System-level changes (kernel/services on NixOS; Homebrew/dock/macOS defaults/launchd on Darwin) still go through the platform-specific rebuild.

NixOS

sudo nixos-rebuild switch --flake .#moby

Darwin

Requires sudo for Homebrew and system defaults. The flake exposes two Darwin configurations that share machines/darwin and only differ in user:

• darwin001 → user alan
• darwin002 → user amunozgo

nix --extra-experimental-features 'nix-command flakes' build .#darwinConfigurations.darwin001.system &&
  sudo ./result/sw/bin/darwin-rebuild switch --flake .#darwin001

Swap darwin001 for darwin002 on the other Mac.

Where should I add packages?

Relative to the root folder of the repo.

	System-wide	home
NixOS	modules/nixos/packages.nix	homes/$USER/packages.nix
Darwin		modules/darwin/packages.nix
Both	modules/shared/packages.nix	[WIP] modules/shared/home-manager.nix

System-wide Darwin packages is not supported yet.

File structure

├── flake.lock
├── flake.nix
├── homes
│   ├── amunoz
│   │   ├── home.nix
│   │   ├── id_ed25519.pub
│   │   ├── moby.nix
│   │   └── packages.nix
│   ├── $USER # per-user specific config
│   │   ├── home.nix
│   │   ├── id_rsa.pub
│   │   ├── moby.nix
│   │   └── packages.nix
│   ├── darwin001
│   │   └── default.nix
│   └── moby # per-server specific config
│       ├── default.nix
│       ├── disko.nix
│       ├── filesystem.nix
│       └── hardware-configuration.nix
├── modules # Shared packages and config files
│   ├── darwin
│   │   └── packages.nix
│   ├── home-manager
│   │   └── default.nix
│   ├── nixos
│   │   ├── default.nix
│   │   └── packages.nix
│   └── shared
│       ├── config
│       │   └── emacs
│       │       ├── config.org
│       │       ├── init.el
│       ├── home-manager.nix
│       └── packages.nix
└── shell.nix
  

Current work

• Trimming the fat
• Isolate GPU packages and services
• Getting a deeper understanding of the system
• Add secrets
• Manage firefox from nix