bash <(curl -L https://nixos.org/nix/install) --daemon

nix-shell -p nix-info --run "nix-info -m"

# 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
    ];

  # Use the systemd-boot EFI boot loader.
  boot.loader.systemd-boot.enable = true;
  boot.loader.efi.canTouchEfiVariables = true;

  # networking.hostName = "nixos"; # 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 = "Europe/Amsterdam";

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

  # Select internationalisation properties.
  i18n.defaultLocale = "en_US.UTF-8";
  #  console = {
  # font = "Lat2-Terminus16";
  # keyMap = "us";
  # useXkbConfig = true; # use xkb.options in tty.
  #  };

  # Enable the X11 windowing system.
  # services.xserver.enable = true;

  # Configure keymap in X11
  # services.xserver.xkb.layout = "us";
  # services.xserver.xkb.options = "eurosign:e,caps:escape";

  # Enable CUPS to print documents.
  # services.printing.enable = true;

  # Enable sound.
  # hardware.pulseaudio.enable = true;
  # OR
  # services.pipewire = {
  #   enable = true;
  #   pulse.enable = true;
  # };

  # Enable touchpad support (enabled default in most desktopManager).
  services.libinput.enable = false;

  #enable avahi-daemon
  services.avahi = {
    enable = true;
    ipv6 = true;
    ipv4 = true;
    publish = {
        enable = true;
        addresses = true;
    };
#   nssmdns4 = true;
  };

  # guest additions
  # not very useful unless desktop enabled, or maybe it just does not work at all
  #virtualisation.virtualbox.guest.enable = true;

  # Define a user account. Don't forget to set a password with ‘passwd’.
  users.users.cherry = {
    isNormalUser = true;
    extraGroups = [ "wheel" ]; # Enable ‘sudo’ for the user.
    openssh.authorizedKeys.keys = [ "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIAVcyLSWwsa8aN+v2PaS1wuHXGVhTdC+43B3eZ9j/C/M" ];
  # packages = with pkgs; [
  #     firefox
  #     tree
  #   ];
  };

  # Define a user account. Don't forget to set a password with ‘passwd’.
  users.users.root = {
    openssh.authorizedKeys.keys = [ "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIAVcyLSWwsa8aN+v2PaS1wuHXGVhTdC+43B3eZ9j/C/M" ];
  };

  # List packages installed in system profile. To search, run:
  # $ nix search wget
  # environment.systemPackages = with pkgs; [
  #   vim # Do not forget to add an editor to edit configuration.nix! The Nano editor is also installed by default.
  #   wget
  # ];

  # 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;
    hostKeys = [
        {
            path = "/etc/ssh/ssh_host_ed25519_key";
            rounds = 100;
            type = "ed25519";
        }
    ];
    settings = {
        PasswordAuthentication = false;
        PubkeyAuthentication = true;
        PermitRootLogin = "prohibit-password";
        UsePAM = false;
        ChallengeResponseAuthentication = false;
        Ciphers = [ "chacha20-poly1305@openssh.com" ];
        GatewayPorts = "Yes";
        KbdInteractiveAuthentication = false;
        KexAlgorithms = [ "curve25519-sha256" "curve25519-sha256@libssh.org" ];
        Macs = [ "hmac-sha2-256-etm@openssh.com" ];
    };
  };

  # 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?
}

{
  imports = [ ];

  boot.initrd.availableKernelModules = [ "ata_piix" "ohci_pci" "ehci_pci" "ahci" "sd_mod" "sr_mod" ];
  boot.initrd.kernelModules = [ ];
  boot.kernelModules = [ ];
  boot.extraModulePackages = [ ];

  fileSystems."/" =
    { device = "/dev/disk/by-uuid/bf0ee7f8-0397-44d6-a3f7-462b848d0912";
      fsType = "ext4";
    };

  fileSystems."/boot" =
    { device = "/dev/disk/by-uuid/B4E2-93D5";
      fsType = "vfat";
      options = [ "fmask=0077" "dmask=0077" ];
    };

  swapDevices =
    [ { device = "/dev/disk/by-uuid/2b67021b-3b31-4e2d-a521-05362ffb39f8"; }
    ];

  # Enables DHCP on each ethernet and wireless interface. In case of scripted networking
  # (the default) this is the recommended approach. When using systemd-networkd it's
  # still possible to use this option, but it's recommended to use it in conjunction
  # with explicit per-interface declarations with `networking.interfaces.<interface>.useDHCP`.
  networking.useDHCP = lib.mkDefault true;
  # networking.interfaces.enp0s3.useDHCP = lib.mkDefault true;

  nixpkgs.hostPlatform = lib.mkDefault "x86_64-linux";
  virtualisation.virtualbox.guest.enable = true;
}

nano /etc/nixos/conf*.nix
df -h .
nixos-rebuild test
nixos-rebuild boot
df -h .

nix-env --delete-generations old
nix-store --gc --print-dead
nix-store --gc --print-live
nix-store --gc

{ config, pkgs, ... }: {
  imports = [
    # builtins.fetchTarbll pins Nixos to a particular release, prevents the lastest release (24.05)from being default installed.
    (builtins.fetchTarball {
      # Pick a release version you are interested in and set its hash, e.g.
      url = "https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/archive/nixos-23.05/nixos-mailserver-nixos-23.05.tar.gz";
      # To get the sha256 of the nixos-mailserver tarball, we can use the nix-prefetch-url command:
      # release="nixos-23.05"; nix-prefetch-url "https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/archive/${release}/nixos-mailserver-${release}.tar.gz" --unpack
      sha256 = "0000000000000000000000000000000000000000000000000000";
    })
  ];

  mailserver = {
    enable = true;
    fqdn = "mail.example.com";
    domains = [ "example.com" ];

    # A list of all login accounts. To create the password hashes, use
    # nix-shell -p mkpasswd --run 'mkpasswd -sm bcrypt'
    loginAccounts = {
      "user1@example.com" = {
        hashedPasswordFile = "/a/file/containing/a/hashed/password";
        aliases = ["postmaster@example.com"];
      };
      "user2@example.com" = { ... };
    };

    # Use Let's Encrypt certificates. Note that this needs to set up a stripped
    # down nginx and opens port 80.
    certificateScheme = "acme-nginx";
  };
  security.acme.acceptTerms = true;
  security.acme.defaults.email = "security@example.com";
}