NixOS & Nix-on-Droid Modular Configuration

✨ A modular Nix configuration with Flakes support for NixOS and Nix-on-Droid ❄️ Snowflake-inspired infrastructure for your systems

🚀 Quick Start

Requirements

• For NixOS: NixOS 25.05 (Warbler) or newer, Flakes enabled in /etc/nixos/configuration.nix:

  { nix.settings.experimental-features = [ "nix-command" "flakes" ]; }

• For Nix-on-Droid: Android device with Nix-on-Droid installed from F-Droid.

Initial Setup on NixOS

# Generate hardware configuration
sudo rm -rf /etc/nixos/*; sudo nixos-generate-config
# Build and activate configuration
sudo nixos-rebuild switch --flake .#$(hostname) --impure

Initial Setup on Nix-on-Droid (e.g., potatoPhone)

# Clone the repository
nix run nixpkgs#git -- clone https://codeberg.org/ponfertato/nixcfg ~/.config/nixpkgs
# Build and activate configuration for your device
nix-on-droid switch --flake ~/.config/nixpkgs#potatoPhone

---

📂 Structure

nixcfg/
├── flake.nix                 # ❄️ Flakes entry point for NixOS and Nix-on-Droid
├── profiles/                 # 🧩 Modular system profiles (base, desktop, users, etc.)
│   ├── base/                 # 🖥️ Core system settings, Nix settings
│   ├── common/               # 👤 User configurations (groups, packages)
│   ├── desktop/              # 🖥️ Base GUI environment (KDE Plasma, X, audio, printing)
│   ├── laptop/               # 💻 Laptop-specific settings (Bluetooth, fingerprint)
│   ├── mobile/               # 📱 Common settings for Nix-on-Droid devices (packages, locale)
│   ├── networking/           # 🌐 Network and firewall settings
│   └── workstation/          # 💻 Workstation-specific settings (Wake-on-LAN)
├── hosts/                    # 🖥️ Host-specific configs (hostname, kernel params, user packages)
│   ├── potatoLaptop/         # 💻 Configuration for potatoLaptop
│   │   └── default.nix       # ⚙️ Host settings (hostname, kernelParams, packages)
│   ├── potatoWork/           # 💻 Configuration for potatoWork
│   │   └── default.nix       # ⚙️ Host settings (hostname, kernelParams, packages)
│   ├── potatoPhone/          # 📱 Configuration for potatoPhone (Nix-on-Droid)
│   │   └── default.nix       # ⚙️ Host settings (hostname, packages)
│   └── potatoTablet/         # 📱 Configuration for potatoTablet (Nix-on-Droid)
│       └── default.nix       # ⚙️ Host settings (hostname, packages)
└── modules/                  # 🧩 Reusable NixOS modules (Docker, Flatpak, Ollama)
    ├── docker.nix            # 🐳 Docker configuration module
    ├── flatpak.nix           # 📦 Flatpak configuration module
    ├── ollama.nix            # 🤖 Ollama service configuration module
    └── home-manager/         # 👤 Home Manager user environment
        ├── common.nix        # 🏠 Core settings (bash, git, firefox, aliases)
        ├── packages.nix      # 📦 User packages (apps, tools)
        ├── potatoLaptop.nix  # 💻 Configuration for potatoLaptop (host-specific packages)
        └── potatoWork.nix    # 💻 Configuration for potatoWork (host-specific packages)

---

🔄 Maintenance

Full System Update (recommended)

nix-update-inputs && nix-apply-system && nix-apply-user

Update Only User Environment (fast, no sudo)

nix-apply-user

Update Only System (NixOS)

nix-apply-system

Update Only Flake Inputs (dependencies)

nix-update-inputs

Manual Update (if needed)

# Update flake inputs (nixpkgs, hardware, etc.)
nix flake update
# Rebuild and activate the system (NixOS) with hardware config regeneration
sudo nixos-generate-config && sudo nixos-rebuild switch --flake .#$(hostname) --impure
# Rebuild and activate the system (Nix-on-Droid)
nix-on-droid switch --flake .#<device_name>

Garbage Collection

nix-gc

Package Search

nix-search <package>          # in stable (nixos-25.05)
nix-search-unstable <package> # in unstable

---

✨ Key Features

• 🔄 Automatic Updates: Weekly GC and auto-upgrade (NixOS)
• 🧩 Modular Design: Easy to maintain and extend via profiles and separated modules
• 💻 Multi-Device Support: Share configs between NixOS and Nix-on-Droid machines
• 🛡️ Reproducible Builds: Fully declarative configuration with Flakes
• ⚙️ Optimized Nix Settings: Includes custom substituters for faster builds
• 👤 Declarative User Environment: Managed via Home Manager (apps, aliases, dotfiles)

---

🛠️ Customization

Create New Profile

1. Add profiles/new-profile/ directory.
2. Create profiles/new-profile/default.nix containing the NixOS or Nix-on-Droid module.
3. Import the profile in flake.nix for the desired host configuration.

Create New Module

1. Add modules/new-module.nix.
2. Import the module in flake.nix for the desired host configuration.

Hardware Configuration (NixOS only)

• Hardware-specific settings (kernel, CPU microcode, graphics drivers) are managed separately in /etc/nixos/hardware-configuration.nix.
• This file is typically generated by nixos-generate-config and can be manually edited or supplemented with nixos-hardware modules if needed.
• The configuration is included in flake.nix to ensure reproducibility and compatibility with nixos-rebuild.

Manage User Environment

• Core settings (bash, git, firefox, aliases) are defined in:

  modules/home-manager/common.nix
  

• User packages are defined in:

  modules/home-manager/packages.nix
  

• Host-specific packages are defined in:

  modules/home-manager/potatoWork.nix
  modules/home-manager/potatoLaptop.nix
  

• After changes, apply with:

  nix-apply-user