NixOS Configuration

A declarative, modular NixOS/Home Manager flake configuration managing multiple systems with a tag-based architecture for maximum code reuse and flexibility.

Hosts

Host	Type	System	Version	Description
rotterdam	Desktop	x86_64-linux	NixOS Unstable	Primary workstation with gaming, development
io	Laptop	x86_64-linux	NixOS Unstable	Mobile workstation
alexandria	Server/NAS	x86_64-linux	NixOS 25.05	Personal server running Nextcloud, Forgejo, Jellyfin, Vaultwarden
trantor	VPS	aarch64-linux	NixOS 25.05	Oracle Cloud instance

Key Features

Architecture

• Tag-based module system - Compose configurations using tags instead of traditional inheritance
• Flake-based - Fully reproducible builds with locked dependencies
• Multi-platform - Supports both x86_64 and aarch64 architectures
• Deployment automation - Remote deployment via deploy-rs

Desktop Experience

• Niri compositor - Custom fork with auto-centering window columns
• Unified theming - Stylix-based theming
• Wayland-native - Full Wayland support
• Ephemeral root - Impermanent filesystem using BTRFS for atomic rollback capability

Self-Hosted Services

• Nextcloud - Cloud storage with calendar, contacts, and notes
• Forgejo - Self-hosted Git server
• Jellyfin - Media streaming
• Vaultwarden - Password manager backend
• LibreSpeed - Network speed testing
• All services behind Nginx and Tailscale with automatic SSL via Let's Encrypt

Security

• Agenix - Encrypted secrets management
• Tailscale - Zero-config VPN mesh network
• Firewall - Configured on all hosts
• SSH key-based authentication

Repository Structure

.
├── flake.nix                    # Main flake definition
├── utils.nix                    # Tag-based module system utilities
├── nixosConfigurations.nix      # Host definitions with tags
├── homeConfigurations.nix       # User configurations
├── deploy.nix                   # Remote deployment configuration
├── hosts/
│   ├── alexandria/              # Server-specific config
│   ├── io/                      # Laptop-specific config
│   ├── rotterdam/               # Desktop-specific config
│   ├── trantor/                 # VPS-specific config
│   └── modules/
│       ├── common/              # Shared base configuration
│       ├── desktop/             # Desktop environment setup
│       ├── server/              # Server-specific modules
│       └── [tag].nix            # Optional feature modules
├── users/
│   └── modules/                 # Home Manager configurations
│       └── [tag].nix            # Optional feature modules
├── packages/                    # Custom package definitions
└── secrets/                     # Encrypted secrets (agenix)

Tag System

Configurations are composed using tags that map to modules:

Common Tags (all hosts):

• common - Base system configuration (automatically applied)

General Tags:

• desktop - Mostly full desktop environment with Niri WM
• dev - Development tools and environments
• gaming - Steam, Heroic, gamemode, controller support
• ephemeral - Impermanent root filesystem
• networkmanager - WiFi and network management
• libvirtd - KVM/QEMU virtualization
• podman - Container runtime
• bluetooth - Bluetooth support
• fwupd - Firmware update daemon

Server Tags:

• server - Server-specific configuration

Usage

Rebuilding a Configuration

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

# Remote deployment
deploy .#hostname

Updating Dependencies

nix flake update

Adding a New Host

1. Create host directory in hosts/
2. Define configuration in nixosConfigurations.nix with appropriate tags
3. Add deployment profile in deploy.nix if needed

Dependencies

• nixpkgs - Stable (25.05) and unstable channels
• home-manager - User configuration
• agenix - Secrets management
• disko - Declarative disk partitioning
• stylix - System-wide theming
• niri-flake - Wayland compositor (custom fork)
• impermanence - Ephemeral filesystem support
• deploy-rs - Remote deployment
• nix-flatpak - Declarative Flatpak management