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:

nixos-generate-config --root /mnt

2. Clone and apply

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:

# 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:

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.