[NixOS] Add airgapped machine

nixos/base.nix

@@ -6,10 +6,6 @@
     ./essential.nix
   ];
 
-  nixpkgs.overlays = [
-    (import ../dotfiles/config/xmonad/overlay.nix)
-  ];
-
   # Allow all the things
   nixpkgs.config.allowUnfree = true;
   nixpkgs.config.permittedInsecurePackages = [
@@ -19,7 +15,6 @@
   # Disabling these waits disables the stuck on boot up issue
   systemd.services.systemd-udev-settle.enable = false;
   systemd.services.NetworkManager-wait-online.enable = false;
-  networking.firewall.enable = false;
 
   # Security
   programs.gnupg.agent = { enable = true; enableSSHSupport = true; };
@@ -30,6 +25,7 @@
     include ipsec.d/ipsec.nm-l2tp.secrets
   '';
 
+  networking.firewall.enable = false;
   networking.networkmanager = {
     enable = true;
     enableStrongSwan = true;

nixos/essential.nix

@@ -15,6 +15,9 @@ let
   python-with-my-packages = pkgs.python3.withPackages my-python-packages;
 in
 {
+  nixpkgs.overlays = [
+    (import ../dotfiles/config/xmonad/overlay.nix)
+  ];
   environment.systemPackages = with pkgs; [
     python-with-my-packages
 
@@ -75,6 +78,7 @@ in
     playerctl
 
     # Tools
+    cachix
     binutils
     gawk
     gitFull

nixos/flake.nix

@@ -78,6 +78,10 @@
         system = "aarch64-linux";
         modules = [ forAll piHardware ./machines/biskcomp.nix ];
       };
+      air-gapped-pi = nixpkgs.lib.nixosSystem {
+        system = "aarch64-linux";
+        modules = [ forAll piHardware ./machines/air-gapped-pi.nix ];
+      };
     };
   };
 }

nixos/machines/air-gapped-pi.nix

@@ -0,0 +1,13 @@
+{
+  imports = [
+    ../internet-computer.nix
+    ../raspberry-pi.nix
+    ../base.nix
+  ];
+
+  networking.hostName = "air-gapped-pi";
+  hardware.video.hidpi.enable = true;
+  networking.enable = false;
+
+  system.stateVersion = "21.05";
+}

nixos/machines/biskcomp.nix

@@ -2,6 +2,7 @@
   imports = [
     ../internet-computer.nix
     ../raspberry-pi.nix
+    ../base.nix
   ];
 
   networking.hostName = "biskcomp";

nixos/raspberry-pi.nix

@@ -1,10 +1,6 @@
 { config, pkgs, ... }:
 
 {
-  imports = [
-    ./base.nix
-  ];
-
   hardware.raspberry-pi."4".fkms-3d.enable = true;
 
   boot = {