nixos-config/nixos/machines/robi/network-wireguard.nix

{ pkgs, config, ... }:
{
  # networking.firewall.trustedInterfaces = [ "wg0" ];
  networking.firewall.allowedUDPPorts = [ 51820 ];
  sops.secrets.wireguard_private = { };
  boot.kernel.sysctl."net.ipv4.ip_forward" = true;

  # Enable WireGuard
  networking.wg-quick.interfaces = {
    # Hub and Spoke Setup
    # https://www.procustodibus.com/blog/2020/11/wireguard-hub-and-spoke-config/
    wg0 = {
      address = [ "10.100.0.1/32" ];
      listenPort = 51820; # to match firewall allowedUDPPorts (without this wg uses random port numbers)
      privateKeyFile = config.sops.secrets.wireguard_private.path;
      mtu = 1280;

      postUp = ''
        ${pkgs.iptables}/bin/iptables -A FORWARD -i wg0 -j ACCEPT
      '';
      postDown = ''
        ${pkgs.iptables}/bin/iptables -D FORWARD -i wg0 -j ACCEPT
      '';

      # clients
      peers = [
        {
          # chungus
          publicKey = "wb54y/fG8ocSH9QrDmfajez/fUcJBZK369xLu37XBHk=";
          allowedIPs = [ "10.100.0.2/32" ];
        }
        {
          # sterni
          publicKey = "SdMRgC5IM7dywzZxLAHm45cpj9J3IENTMClZm1BxbV4=";
          allowedIPs = [ "10.100.0.3/32" ];
        }
        {
          # iphone
          publicKey = "XPVzH+wBLsqukTHHjngkGJhYN0nRdQ7esadiimMJQnI=";
          allowedIPs = [ "10.100.0.4/32" ];
        }
        {
          # tina
          publicKey = "RZsuQfWfAQLMm45ZiuNLBwcpL+GEbPYTRTrASFzMCFQ=";
          allowedIPs = [ "10.100.0.5/32" ];
        }
        {
          # cream
          publicKey = "R1Vk1DDG/LsVU0HHRDmOJshXOVnNzPVbuv5hP7ZSGEQ=";
          allowedIPs = [ "10.100.0.6/32" ];
        }
      ];
    };
  };
}