Add conditionals and assertions

desktop.nix

@@ -451,6 +451,13 @@ let
   ''}";
 in
 {
+  assertions = [
+    {
+      assertion = config.users.users ? "vili";
+      message = "User 'vili' needed for desktop!";
+    }
+  ];
+
   environment.systemPackages = with pkgs; [
     i3status
     rofi

hardware-specific/amd-laptop.nix

@@ -8,7 +8,7 @@
   boot.initrd.kernelModules = [ "amdgpu" ];
 
   services = {
-    xserver = {
+    xserver = pkgs.lib.mkIf config.services.xserver.enable {
       videoDrivers = [
         "amdgpu"
         "modesetting"

hardware-specific/keychron-q11.nix

@@ -1,7 +1,7 @@
 # Config for Keychron Q11 keyboard
 { config, pkgs, ... }:
 {
-  environment.systemPackages = with pkgs; [ via ];
+  environment.systemPackages = with pkgs; if config.services.xserver.enable then [ via ] else [ ];
 
   # Keychron Q11
   services.udev.extraRules = ''

hardware-specific/trackball.nix

@@ -1,6 +1,13 @@
 # Config for my Logitech trackball
 { config, pkgs, ... }:
 {
+  assertions = [
+    {
+      assertion = config.services.xserver.enable;
+      message = "Trackball does not work without a desktop!";
+    }
+  ];
+
   disabledModules = [ "services/hardware/libinput.nix" ];
 
   nixpkgs.overlays = [

services/game-streaming.nix

@@ -1,6 +1,13 @@
 # Game streaming software (and possibly services in future)
 { config, pkgs, ... }:
 {
+  assertions = [
+    {
+      assertion = config.services.xserver.enable;
+      message = "Game streaming does not work without a desktop!";
+    }
+  ];
+
   environment.systemPackages = with pkgs; [
     moonlight-qt
     parsec-bin

services/redshift.nix

@@ -1,6 +1,12 @@
 # Redshift bluelight reducer
 { config, pkgs, ... }:
 {
+  assertions = [
+    {
+      assertion = config.services.xserver.enable;
+      message = "Redshift does not work without a desktop!";
+    }
+  ];
   services = {
     redshift = {
       executable = "/bin/redshift-gtk";

services/vaultwarden.nix

@@ -1,4 +1,4 @@
-# Nextcloud instance
+# Vaultwarden instance
 { config, pkgs, ... }:
 {
   networking.firewall.allowedTCPPorts = [