nixos-config/config/hosts/ursa-major/default.nix

# 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; };
  boot.kernelParams = [
    "cgroup_enable=cpuset"
    "cgroup_memory=1"
    "cgroup_enable=memory"
  ];

  networking.hostName = "ursa-major"; # 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";

  # services.earlyoom.enable = true;

  services.k3s.enable = true;
  services.k3s.role = "server";
  services.k3s.extraFlags = toString [
    # "--kubelet-arg=v=4" # Optionally add additional args to k3s
  ];

  environment.variables = {
    KUBECONFIG = "/home/nixos/.kube/config";
  };

  services.influxdb.enable = true;

  services.telegraf.enable = true;
  services.telegraf.extraConfig = {
    outputs.influxdb = {
      urls = [ "http://127.0.0.1:8086" ];
      database = "telegraf";
    };

    inputs.net = { };
    inputs.netstat = { };
    inputs.file = {
      files = [ "/sys/class/thermal/thermal_zone0/temp" ];
      name_override = "cpu_temperature";
      data_format = "value";
      data_type = "integer";
    };
    inputs.exec = {
      commands = [ "${pkgs.libraspberrypi}/bin/vcgencmd measure_temp" ];
      name_override = "gpu_temperature";
      data_format = "grok";
      grok_patterns = [ "%{NUMBER:value:float}" ];
    };
    inputs.cpu = {
      ## Whether to report per-cpu stats or not
      percpu = true;
      ## Whether to report total system cpu stats or not
      totalcpu = true;
      ## Comment this line if you want the raw CPU time metrics
      fielddrop = [ "time_*" ];
    };
    inputs.disk = {
      ## By default, telegraf gather stats for all mountpoints.
      ## Setting mountpoints will restrict the stats to the specified mountpoints.
      # mount_points = ["/"]

      ## Ignore some mountpoints by filesystem type. For example (dev)tmpfs (usually
      ## present on /run, /var/run, /dev/shm or /dev).
      ignore_fs = [ "tmpfs" "devtmpfs" ];
    };
    inputs.diskio = {
      ## By default, telegraf will gather stats for all devices including
      ## disk partitions.
      ## Setting devices will restrict the stats to the specified devices.
      # devices = ["sda", "sdb"]
      ## Uncomment the following line if you need disk serial numbers.
      # skip_serial_number = false
    };
    inputs.kernel = { };
    inputs.mem = { };
    inputs.processes = { };
    inputs.swap = { };
    inputs.system = { };
    inputs.interrupts = { };
    inputs.linux_sysctl_fs = { };
  };

  # 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; [
    git
    htop
    libraspberrypi
    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?

}