# Cryodev NixOS Configuration Documentation

Welcome to the documentation for the **cryodev** NixOS infrastructure.

## Quick Links

### Getting Started

- [Prerequisites](getting-started/prerequisites.md) - Required tools
- [Adding a New Raspberry Pi](getting-started/new-client.md) - Complete workflow for new clients
- [SD Image Reference](getting-started/sd-image.md) - Details on image building
- [First Installation (Server)](getting-started/first-install.md) - Bootstrap for x86_64 hosts
- [Reinstallation](getting-started/reinstall.md) - Reinstall with hardware changes

### Services

- [SOPS Secrets](services/sops.md) - Secret management with sops-nix
- [Headscale](services/headscale.md) - Self-hosted Tailscale server
- [Headplane](services/headplane.md) - Web UI for Headscale
- [Tailscale](services/tailscale.md) - Mesh VPN client
- [Mailserver](services/mailserver.md) - Email stack (Postfix/Dovecot)
- [Forgejo](services/forgejo.md) - Git hosting with CI/CD
- [Netdata](services/netdata.md) - Monitoring and alerting

### Deployment

- [Continuous Deployment](deployment/cd.md) - Push- and pull-based deployment
- [DNS Configuration](deployment/dns.md) - Required DNS records

## Architecture

```
                    Internet
                        |
                   cryodev.xyz
                        |
              +-------------------+
              |   cryodev-main    |
              |   (x86_64 Server) |
              +-------------------+
              | - Headscale       |
              | - Headplane       |
              | - Forgejo         |
              | - Mailserver      |
              | - Netdata Parent  |
              +-------------------+
                        |
               Tailscale Mesh VPN
                        |
              +-------------------+
              |   cryodev-pi      |
              | (Raspberry Pi 4)  |
              +-------------------+
              | - Tailscale       |
              | - Netdata Child   |
              | - Comin (GitOps)  |
              +-------------------+
```

## Installation Scenarios

| Scenario | Description | Guide |
|----------|-------------|-------|
| **New Raspberry Pi** | Create config, build image, flash | [new-client.md](getting-started/new-client.md) |
| **First Installation (Server)** | x86_64 host, manual installation | [first-install.md](getting-started/first-install.md) |
| **Reinstallation** | Existing host, new hardware | [reinstall.md](getting-started/reinstall.md) |

For Raspberry Pi: [SD Image Reference](getting-started/sd-image.md)

## Directory Structure

```
.
├── flake.nix           # Entry point, inputs and outputs
├── constants.nix       # Central configuration (domains, IPs, ports)
├── hosts/              # Host-specific configurations
│   ├── cryodev-main/
│   └── cryodev-pi/
├── modules/            # Reusable NixOS modules
│   └── nixos/
├── pkgs/               # Custom packages
├── overlays/           # Nixpkgs overlays
├── templates/          # Templates for new hosts
├── scripts/            # Helper scripts (install.sh)
├── apps/               # Nix apps (rebuild)
└── lib/                # Helper functions (utils.nix)
```

## Deployment Strategies

| Host | Strategy | Tool | Description |
|------|----------|------|-------------|
| `cryodev-main` | Pull-based | Comin | Polls the repository for changes |
| `cryodev-pi` | Pull-based | Comin | Polls the repository for changes |