config/systems/template/configuration.nix

{
  inputs,
  modulesPath,
  ...
}:
{
  nixpkgs.hostPlatform = "x86_64-linux";
  imports = [
    (modulesPath + "/profiles/qemu-guest.nix")
    inputs.impermanence.nixosModules.impermanence
  ];

  time.timeZone = "Europe/Amsterdam";
  i18n.defaultLocale = "en_US.UTF-8";
  networking.hostName = "nixos-template";
  networking.dhcpcd.enable = false;
  networking.useNetworkd = true;

  boot.loader.systemd-boot.enable = true;
  boot.loader.efi.canTouchEfiVariables = true;
  services.qemuGuest.enable = true;

  nix.settings.trusted-users = [
    "root"
    "@wheel"
  ];
  nix.settings.experimental-features = [
    "nix-command"
    "flakes"
  ];

  users.users."maintenance" = {
    isNormalUser = true;
    group = "maintenance";
    extraGroups = [ "wheel" ];
    password = "1234";
    openssh.authorizedKeys.keyFiles = [ ../../authorized_keys ];
  };
  users.groups."maintenance" = { };
  security.sudo.wheelNeedsPassword = false;
  services.openssh = {
    enable = true;
    settings.PasswordAuthentication = false;
    settings.KbdInteractiveAuthentication = false;
  };
  programs.ssh.startAgent = true;

  services.cloud-init = {
    enable = true;
    network.enable = true;
    config = ''
      system_info:
        distro: nixos
        network:
          renderers: [ 'networkd' ]
        default_user:
          name: ops
      users:
        - default
      ssh_pwauth: false
      chpasswd:
        expire: false
      cloud_init_modules:
        - migrator
        - seed_random
        - growpart
        - resizefs
      cloud_config_modules:
        - disk_setup
        - mounts
        - set-passwords
        - ssh
      cloud_final_modules: []
      datasource_list:
        - NoCloud
      growpart:
        devices: ['/dev/sda2']
      # Resize the filesystem along with the partition
      runcmd:
        - btrfs filesystem resize max /nix
    '';
  };

  boot.supportedFilesystems = [ "btrfs" ];
  fileSystems = {
    "/" = {
      device = "none";
      fsType = "tmpfs";
      options = [
        "defaults"
        "mode=755"
      ];
    };
    "/boot" = {
      device = "/dev/disk/by-label/boot";
      fsType = "vfat";
    };
    "/nix" = {
      device = "/dev/disk/by-label/btrfs";
      fsType = "btrfs";
      options = [
        "compress=zstd"
        "subvol=nix"
        "noatime"
      ];
    };
    "/persistent" = {
      device = "/dev/disk/by-label/btrfs";
      fsType = "btrfs";
      options = [
        "compress=zstd"
        "subvol=persistent"
        "noatime"
      ];
      autoResize = true;
      neededForBoot = true;
    };
  };

}