# cyper-servers

NixOS flake configuration for x86_64 server infrastructure.

## Hosts

| Host | IP | DNS | Role |
|------|----|-----|------|
| `cyper-controller` | `192.168.2.2` (static) | `127.0.0.1`, `1.1.1.1` | k3s master, PostgreSQL, DNS/DHCP |
| `cyper-node1` | `192.168.2.30` (static) | `192.168.2.2` | k3s agent |
| `cyper-node2` | `192.168.2.31` (static) | `192.168.2.2` | k3s agent |
| `cyper-cluster` | DHCP | `1.1.1.1`, `8.8.8.8` | k3s agent, Helm |
| `cyper-cloud` | DHCP | `1.1.1.1`, `8.8.8.8` | Cloud tooling (Terraform, AWS CLI) |

## Directory Structure

```
cyper-servers/
├── flake.nix                        # Main flake — declares all hosts
├── nixos/
│   ├── default.nix                  # Shared NixOS config (users, SSH, Nix settings)
│   ├── hardware.nix                 # x86_64 bootloader & filesystem config
│   ├── settings.nix                 # Locale & timezone
│   └── packages.nix                 # Common system packages
├── home/                            # Home Manager (shared across all hosts)
│   ├── default.nix
│   ├── packages.nix
│   ├── git.nix
│   ├── shell.nix
│   └── neovim/
└── hosts/
    ├── services/
    │   ├── k3s-master.nix           # Reusable k3s server module
    │   └── k3s-agent.nix            # Reusable k3s agent module
    ├── cyper-controller/
    │   ├── configuration.nix        # Static IP, imports master + postgres + dns
    │   ├── postgres.nix             # PostgreSQL (x86_64 tuned)
    │   └── dns.nix                  # dnsmasq DNS + DHCP server
    ├── cyper-node1/
    │   └── configuration.nix        # Static 192.168.2.30, k3s agent
    ├── cyper-node2/
    │   └── configuration.nix        # Static 192.168.2.31, k3s agent
    ├── cyper-cluster/
    │   └── configuration.nix        # DHCP, k3s agent + Helm
    └── cyper-cloud/
        └── configuration.nix        # DHCP, Terraform + AWS CLI
```

## Quick Start

### 1. Install NixOS on each machine

Boot from a standard NixOS x86_64 ISO and partition your disk with labels `boot` (FAT32) and `nixos` (ext4), then:

```bash
nixos-generate-config --root /mnt
```

### 2. Clone and apply

```bash
git clone <your-repo> /etc/nixos
cd /etc/nixos
nixos-rebuild switch --flake .#cyper-controller   # on the controller
nixos-rebuild switch --flake .#cyper-node1        # on node1
# ... etc
```

### 3. k3s cluster setup

After `cyper-controller` is up, retrieve the node token and apply it on each agent:

```bash
# On cyper-controller:
cat /var/lib/rancher/k3s/server/node-token

# On each agent, set the token in the k3s service environment:
# Edit hosts/services/k3s-agent.nix and add:
#   tokenFile = "/etc/k3s-token";
# Then create /etc/k3s-token with the token value and rebuild.
```

## Customization

### Change username

Edit `flake.nix`:
```nix
primaryUser = "your-username";
```

### Add packages per host

Edit `hosts/<hostname>/configuration.nix` and add to `environment.systemPackages`.

### Adjust PostgreSQL

Edit `hosts/cyper-controller/postgres.nix` — memory settings are pre-tuned for x86_64 with 8GB+ RAM.

### DNS entries

Edit `hosts/cyper-controller/dns.nix` to add static A records or adjust DHCP ranges.

## Locale & Timezone

Defaults (same as cyper-rpi):
- **Timezone**: `Europe/Berlin`
- **Locale**: `en_US.UTF-8` with German regional settings

Change in `nixos/settings.nix`.