# NixOS / Nix-Darwin's Submodules

This directory contains modular NixOS and Nix-Darwin configurations organized by platform and
functionality.

## Current Structure

```
modules/
├── README.md
├── base/                    # Common configuration for all platforms
│   ├── default.nix
│   ├── fonts.nix           # System font configuration
│   ├── nix.nix            # Nix package manager settings
│   ├── overlays.nix       # Package overlays
│   ├── packages.nix       # Essential system packages
│   ├── security.nix       # Basic security settings
│   └── users.nix          # User management
├── darwin/                  # macOS-specific modules
│   ├── README.md
│   ├── apps.nix           # macOS applications
│   ├── default.nix
│   ├── nix-core.nix       # Core Nix configuration
│   ├── security.nix       # macOS security settings
│   ├── ssh.nix           # SSH configuration
│   ├── system.nix        # System-level settings
│   └── users.nix         # macOS user management
└── nixos/                   # NixOS-specific modules
    ├── base/               # Base NixOS configuration
    │   ├── auditd.nix     # Audit trail for root sessions and credentials
    │   ├── btop.nix       # System resource monitor
    │   ├── btrbk.nix      # Local btrfs snapshots
    │   ├── core.nix       # Core system settings
    │   ├── default.nix
    │   ├── i18n.nix       # Internationalization
    │   ├── locate.nix     # locate/updatedb file search
    │   ├── monitoring.nix # System monitoring
    │   ├── networking/    # Network configuration
    │   ├── nix.nix        # Nix settings
    │   ├── packages.nix   # System packages
    │   ├── restic-backup.nix # Encrypted off-host backups (see ../BACKUP.md)
    │   ├── ssh.nix        # SSH daemon configuration
    │   ├── trash.nix      # Trash retention cleanup
    │   ├── user-group.nix # User and group management
    │   └── zram.nix       # ZRAM swap configuration
    ├── desktop.nix         # Desktop environment configuration
    ├── desktop/            # Desktop-specific modules
    │   ├── canokey.nix    # CanoKey hardware token
    │   ├── computer-use.nix # Headless X11/i3 session for AI agents
    │   ├── default.nix
    │   ├── fhs.nix        # FHS environment
    │   ├── fonts.nix      # Desktop fonts
    │   ├── gaming.nix     # Gaming support
    │   ├── misc.nix       # Miscellaneous desktop settings
    │   ├── networking/    # Network-related desktop configs
    │   ├── nix.nix        # Desktop Nix settings
    │   ├── peripherals.nix # Peripheral device configuration
    │   ├── power.nix      # Power management
    │   ├── security.nix   # Desktop security settings
    │   ├── ssh.nix        # Desktop SSH configuration
    │   ├── containers.nix # Container engines (podman/docker)
    │   └── xdg.nix       # XDG base directory settings
    └── server/             # Server-specific modules
        ├── qemu-guest-hardware-configuration.nix
        ├── qemu-guest.nix  # VM guest base module (libvirt/QEMU guests)
        ├── server-aarch64.nix
        └── server.nix
```

System hardening modules (kernel baseline, AppArmor, app sandboxes) live under
[`../hardening/`](../hardening/README.md).

## Module Categories

### 1. **Base Modules** (`base/`)

Common configuration shared between NixOS and macOS:

- System fonts and localization
- Essential packages and tools
- Basic security settings
- User management
- Package overlays

### 2. **macOS Modules** (`darwin/`)

macOS-specific configuration:

- macOS applications and system settings
- Security configurations tailored for macOS
- SSH and system-level settings
- Package compatibility fixes

### 3. **NixOS Modules** (`nixos/`)

Platform-specific NixOS configuration:

- **Base**: Core system settings and services
- **Desktop**: Desktop environment and GUI applications
- **Server**: Server-specific optimizations and services

## Usage

There is no automatic platform detection. Each host's entry under `outputs/<system>/src/` lists its
imports explicitly:

- **NixOS Systems**: import `nixos/` modules
- **macOS Systems**: import `darwin/` modules
- **Both**: import `base/` modules for shared configuration