# Edit this configuration file to define what should be installed on
# your system. Help is available in the configuration.nix(5) man page, on
# https://search.nixos.org/options and in the NixOS manual (`nixos-help`).

{ config, lib, pkgs, ... }:

{
  imports =
    [
      # Include the results of the hardware scan.
      ./hardware-configuration.nix
    ];

  nix.settings.experimental-features = [ "nix-command" "flakes" ];
  nixpkgs.config.allowUnfree = true;

  # Use the extlinux boot loader. (NixOS wants to enable GRUB by default)
  boot.loader.grub.enable = false;
  # Enables the generation of /boot/extlinux/extlinux.conf
  boot.loader.generic-extlinux-compatible.enable = true;

  # For k3s
  boot.kernel.sysctl = { "net.ipv4.ip_forward" = 1; };

  networking.hostName = "nixos-rpi"; # Define your hostname.
  # Pick only one of the below networking options.
  networking.wireless.enable = true; # Enables wireless support via wpa_supplicant.
  # networking.networkmanager.enable = true;  # Easiest to use and most distros use this by default.

  # Set your time zone.
  time.timeZone = "America/New_York";

  # Configure network proxy if necessary
  # networking.proxy.default = "http://user:password@proxy:port/";
  # networking.proxy.noProxy = "127.0.0.1,localhost,internal.domain";

  # [Unit]
  # Description=Lightweight Kubernetes
  # Documentation=https://k3s.io
  # Wants=network-online.target
  # After=network-online.target

  # [Install]
  # WantedBy=multi-user.target

  # [Service]
  # Type=${SYSTEMD_TYPE}
  # EnvironmentFile=-/etc/default/%N
  # EnvironmentFile=-/etc/sysconfig/%N
  # EnvironmentFile=-${FILE_K3S_ENV}
  # KillMode=process
  # Delegate=yes
  # # Having non-zero Limit*s causes performance problems due to accounting overhead
  # # in the kernel. We recommend using cgroups to do container-local accounting.
  # LimitNOFILE=1048576
  # LimitNPROC=infinity
  # LimitCORE=infinity
  # TasksMax=infinity
  # TimeoutStartSec=0
  # Restart=always
  # RestartSec=5s
  # ExecStartPre=/bin/sh -xc '! /usr/bin/systemctl is-enabled --quiet nm-cloud-setup.service 2>/dev/null'
  # ExecStartPre=-/sbin/modprobe br_netfilter
  # ExecStartPre=-/sbin/modprobe overlay
  # ExecStart=${BIN_DIR}/k3s \\
  #     ${CMD_K3S_EXEC}

  # Adapted from https://get.k3s.io/
  systemd.services.k3s = {
    description = "Lightweight Kubernetes";
    documentation = [ "https://k3s.io" ];
    serviceConfig = {
      Type = "notify";
      # EnvironmentFile = "-/etc/default/%N";
      # EnvironmentFile = "-/etc/sysconfig/%N";
      # EnvironmentFile = -${FILE_K3S_ENV};
      KillMode = "process";
      Delegate = "yes";
      # Having non-zero Limit*s causes performance problems due to accounting overhead
      # in the kernel. We recommend using cgroups to do container-local accounting.
      LimitNOFILE = 1048576;
      LimitNPROC = "infinity";
      LimitCORE = "infinity";
      TasksMax = "infinity";
      TimeoutStartSec = 0;
      Restart = "always";
      RestartSec = "5 s";
      # ExecStartPre = /bin/sh - xc '! /usr/bin/systemctl is-enabled --quiet nm-cloud-setup.service 2>/dev/null';
      # ExecStartPre = -/sbin/modprobe br_netfilter;
      # ExecStartPre = -/sbin/modprobe overlay;
      ExecStart = "${pkgs.k3s}/bin/k3s server --write-kubeconfig-mode=644";
    };
    after = [ "network-online.target" ];
    wants = [ "network-online.target" ];
    wantedBy = [ "multi-user.target" ];
  };

  systemd.services.k3s.enable = true;

  # Define a user account. Don't forget to set a password with ‘passwd’.
  users.users.nixos = {
    isNormalUser = true;
    extraGroups = [ "wheel" ]; # Enable ‘sudo’ for the user.
    packages = with pkgs; [ ];
  };

  # List packages installed in system profile. To search, run:
  # $ nix search wget
  environment.systemPackages = with pkgs; [
    docker
    git
    k3s
    nodejs_21
    nodePackages.pnpm
    pulumi
    pulumiPackages.pulumi-language-nodejs
    slirp4netns # required by k3s
    vim
  ];

  # Some programs need SUID wrappers, can be configured further or are
  # started in user sessions.
  # programs.mtr.enable = true;
  # programs.gnupg.agent = {
  #   enable = true;
  #   enableSSHSupport = true;
  # };

  # List services that you want to enable:

  # Enable the OpenSSH daemon.
  services.openssh.enable = true;

  # Open ports in the firewall.
  # networking.firewall.allowedTCPPorts = [ ... ];
  # networking.firewall.allowedUDPPorts = [ ... ];
  # Or disable the firewall altogether.
  networking.firewall.enable = false;

  # Copy the NixOS configuration file and link it from the resulting system
  # (/run/current-system/configuration.nix). This is useful in case you
  # accidentally delete configuration.nix.
  # system.copySystemConfiguration = true;

  # This option defines the first version of NixOS you have installed on this particular machine,
  # and is used to maintain compatibility with application data (e.g. databases) created on older NixOS versions.
  #
  # Most users should NEVER change this value after the initial install, for any reason,
  # even if you've upgraded your system to a new NixOS release.
  #
  # This value does NOT affect the Nixpkgs version your packages and OS are pulled from,
  # so changing it will NOT upgrade your system - see https://nixos.org/manual/nixos/stable/#sec-upgrading for how
  # to actually do that.
  #
  # This value being lower than the current NixOS release does NOT mean your system is
  # out of date, out of support, or vulnerable.
  #
  # Do NOT change this value unless you have manually inspected all the changes it would make to your configuration,
  # and migrated your data accordingly.
  #
  # For more information, see `man configuration.nix` or https://nixos.org/manual/nixos/stable/options#opt-system.stateVersion .
  system.stateVersion = "24.05"; # Did you read the comment?

}