NixOS Configuration

This repository contains a modular NixOS configuration for managing multiple host systems using Nix flakes. The configuration is designed to be maintainable, reusable, and organized around a clear separation of concerns.

🖥️ Host Systems

The configuration currently manages three host systems:

• pluto (x86_64-linux) - Desktop system
• juno (x86_64-linux) - Tablet system
• charon (aarch64-linux) - Lenovo ThinkPad X13s

📁 Repository Structure

nixos/
├── hosts/           # Host-specific configurations
│   ├── _shared.nix  # Common configuration shared across all hosts
│   ├── pluto.nix    # Configuration for pluto host
│   ├── juno.nix     # Configuration for juno host
│   └── charon.nix   # Configuration for charon host
├── hardware/        # Hardware-specific configurations
│   ├── pluto.nix    # Hardware configuration for pluto
│   ├── juno.nix     # Hardware configuration for juno
│   └── charon.nix   # Hardware configuration for charon
├── users/           # User account configurations
│   └── maik.nix     # User configuration for maik
├── gui/             # Desktop environment configurations
│   ├── gnome.nix    # GNOME desktop environment
│   ├── plasma.nix   # KDE Plasma desktop environment
│   ├── sway.nix     # Sway window manager
│   └── niri.nix     # Niri window manager
├── capabilities/    # Modular capability configurations
│   ├── chipcards.nix    # Smart card support
│   ├── fan2go.nix       # Fan control
│   ├── gnupg.nix        # GnuPG configuration
│   ├── pipewire.nix     # PipeWire audio system
│   ├── printing.nix     # Printing support
│   ├── scanning.nix     # Document scanning
│   ├── ssh.nix          # SSH configuration
│   ├── steam.nix        # Steam gaming platform
│   ├── vscode.nix       # Visual Studio Code
│   └── vscodium.nix     # VSCodium (open source VS Code)
├── patches/         # Custom patches and modifications
├── flake.nix        # Main flake configuration
└── flake.lock       # Locked dependency versions

🏗️ Architecture

The configuration follows a modular approach:

1. Shared Configuration: Common settings applied to all hosts are defined in hosts/_shared.nix
2. Host-Specific: Each host imports the shared configuration and adds its own customizations
3. Hardware Abstraction: Hardware-specific settings are separated into dedicated files
4. Capability Modules: Features like audio, printing, and development tools are modularized
5. Desktop Environments: GUI configurations are kept separate and can be mixed and matched

🚀 Getting Started

Prerequisites

• NixOS installed on your system
• Nix flakes enabled in your configuration
• Git for cloning the repository

Initial Setup

1. Clone this repository:

   git clone <repository-url>
   cd nixos

2. Build and switch to a configuration:

   # For the juno host
   sudo nixos-rebuild switch --flake .#juno
   
   # For the charon host  
   sudo nixos-rebuild switch --flake .#charon
   
   # For the pluto host
   sudo nixos-rebuild switch --flake .#pluto

Development Environment

A development shell is provided with useful tools:

nix develop

This includes:

• gitMinimal - Git version control
• nil - Nix language server
• alejandra - Nix code formatter

🔧 Configuration Features

Shared Features (All Hosts)

• Boot Configuration: Systemd-boot with silent boot process
• Time Zone: Europe/Berlin
• Localization: German locale and keyboard layout
• Security: Immutable users, sudo access for wheel group
• Storage: zram swap, fscrypt home directories
• Network: NFS automount for shared storage
• Nix Settings: Flakes enabled, automatic garbage collection, auto-upgrades

Host-Specific Features

Juno (Tablet)

• GNOME desktop environment with GDM
• Power optimization for mobile use
• Bluetooth and WiFi support
• Custom audio equalizer for StarLabs speakers
• Syncthing for file synchronization

Charon (ARM Laptop)

• KDE Plasma desktop environment
• Lenovo ThinkPad X13s ARM support via nixos-x13s
• Autologin with greetd
• Kodi media center
• Custom audio equalizer for X13s speakers
• Podman containerization

Available Capabilities

• Audio: PipeWire with low-latency audio
• Printing: CUPS with driver support
• Scanning: SANE document scanning
• Development: VS Code/VSCodium with extensions
• Security: GnuPG, SSH, smart card support
• Gaming: Steam (when enabled)
• System: Fan control, power management

🛠️ Customization

Adding a New Host

1. Create hardware configuration: hardware/newhost.nix
2. Create host configuration: hosts/newhost.nix
3. Add to flake.nix nixosConfigurations
4. Import desired capabilities and GUI modules

Adding New Capabilities

1. Create a new module in capabilities/
2. Follow the existing pattern of exposing configuration options
3. Import the capability in relevant host configurations

User Management

User configurations are defined in users/. To add a new user:

1. Create users/username.nix
2. Define user account, SSH keys, and shell preferences
3. Import in relevant host configurations

📦 Dependencies

The configuration uses:

• nixpkgs: NixOS 25.05 (stable)
• nixos-x13s: ARM laptop support for ThinkPad X13s

🔄 Maintenance

Updates

The system is configured for automatic updates via system.autoUpgrade, but you can manually update:

# Update flake inputs
nix flake update

# Rebuild with new inputs
sudo nixos-rebuild switch --flake .#<hostname>

Garbage Collection

Automatic garbage collection is enabled, but you can manually clean up:

# Collect garbage older than 7 days
sudo nix-collect-garbage --delete-older-than 7d

# Optimize nix store
sudo nix-store --optimize

📝 Contributing

When making changes:

1. Test configurations in a VM or on non-production systems first
2. Use alejandra to format Nix code
3. Keep the modular structure intact
4. Document any new capabilities or significant changes

🔒 Security Notes

• Users are immutable (defined in configuration)
• SSH is configured with public key authentication only
• Home directories use fscrypt encryption
• Firewall is enabled with specific port allowances
• Automatic security updates are enabled

📞 Support

This is a personal NixOS configuration. For general NixOS help:

• NixOS Manual
• Nix Package Search
• NixOS Discourse