feat(system): add Flatpak support

chore(system): replace test data with abort messages

system/flake.nix

@@ -37,8 +37,7 @@
     }:
     let
       ###*** IMPORTANT: Please set your system's hostname here ***###
-      #hostName = builtins.abort "Please set the 'hostName' variable in flake.nix";
-      hostName = "myHost";
+      hostName = builtins.abort "Please set the 'hostName' variable in flake.nix";
 
       /*
         What kind of system are you running NixOS on?

system/host/configuration.nix

@@ -57,6 +57,14 @@ in
     # Change the default text editor. Options are "emacs", "nano", or "vim".
     editor = "nano";
 
+    ui.flatpak = {
+      # Enable Flatpak support.
+      enable = false;
+
+      # Define Flatpak packages to install.
+      packages = [ ];
+    };
+
     # Additional system packages to install.
     packages = [ ];
 

system/host/hardware-configuration.nix

@@ -1,63 +1 @@
-#builtins.abort "Please run 'nixos-generate-config --show-hardware-config' and copy the output into hardware-configuration.nix"
-
-# Surface Laptop Go 1st gen
-{
-  config,
-  lib,
-  pkgs,
-  modulesPath,
-  ...
-}:
-{
-  imports = [ (modulesPath + "/installer/scan/not-detected.nix") ];
-
-  boot = {
-    initrd = {
-      availableKernelModules = [
-        "xhci_pci"
-        "nvme"
-        "usb_storage"
-        "usbhid"
-        "sd_mod"
-      ];
-      kernelModules = [ ];
-      luks.devices."luks-5a91100b-8ed9-4090-b1d8-d8291000fe38".device = "/dev/disk/by-uuid/5a91100b-8ed9-4090-b1d8-d8291000fe38";
-    };
-
-    kernelModules = [ "kvm-intel" ];
-    extraModulePackages = [ ];
-  };
-
-  fileSystems = {
-    "/" = {
-      device = "/dev/disk/by-uuid/76d67291-5aed-4f2a-b71f-1c2871cefe24";
-      fsType = "btrfs";
-      options = [ "subvol=@,compress=zstd,discard" ];
-    };
-    "/boot" = {
-      device = "/dev/disk/by-uuid/0C53-A645";
-      fsType = "vfat";
-    };
-  };
-
-  swapDevices = [
-    {
-      device = "/swapfile";
-      size = 4096;
-    }
-  ];
-
-  networking = {
-    # 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`.
-    useDHCP = lib.mkDefault true;
-    # networking.interfaces.wlp0s20f3.useDHCP = lib.mkDefault true;
-
-    # Set the hostname.
-    #hostName = "Dimaga";
-  };
-
-  hardware.cpu.intel.updateMicrocode = lib.mkDefault config.hardware.enableRedistributableFirmware;
-}
+builtins.abort "Please run 'nixos-generate-config --show-hardware-config' and copy the output into hardware-configuration.nix"

system/modules/ui/desktops/kde.nix

@@ -20,6 +20,15 @@ in
   config = lib.mkIf cfg.enable {
     aux.system.ui.desktops.enable = true;
 
+    programs.dconf.enable = true;
+
+    # Fix blank messages in KMail. See https://nixos.wiki/wiki/KDE#KMail_Renders_Blank_Messages
+    environment.sessionVariables = {
+      NIX_PROFILES = "${pkgs.lib.concatStringsSep " " (
+        pkgs.lib.reverseList config.environment.profiles
+      )}";
+    };
+
     services = {
       displayManager.sddm.enable = true;
       desktopManager.plasma6.enable = true;

system/modules/ui/flatpak.nix

@@ -0,0 +1,85 @@
+# Enable support for Flatpak applications
+{
+  nix-flatpak,
+  pkgs,
+  config,
+  lib,
+  ...
+}:
+
+let
+  cfg = config.aux.system.ui.flatpak;
+in
+with lib;
+{
+  options = {
+    aux.system.ui.flatpak = {
+      enable = mkEnableOption (mdDoc "Enables Flatpak support.");
+      packages = lib.mkOption {
+        description = "Flatpak packages to install.";
+        type = lib.types.listOf lib.types.str;
+        default = [ ];
+        example = lib.literalExpression "[ \"com.valvesoftware.Steam\" ]";
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    # Enable Flatpak
+    services.flatpak = {
+      enable = true;
+
+      # Manage all Flatpak packages and remotes
+      uninstallUnmanaged = true;
+
+      # Enable automatic updates alongside nixos-rebuild
+      update.onActivation = true;
+
+      # Add remote(s)
+      remotes = [
+        {
+          name = "flathub";
+          location = "https://dl.flathub.org/repo/flathub.flatpakrepo";
+        }
+      ];
+
+      # Install base Flatpaks. For details, see https://github.com/gmodena/nix-flatpak
+      packages = cfg.packages;
+    };
+
+    # Workaround for getting Flatpak apps to use system fonts, icons, and cursors
+    # For details (and source), see https://github.com/NixOS/nixpkgs/issues/119433#issuecomment-1767513263
+    # NOTE: If fonts in Flatpaks appear incorrect (like squares), run this command to regenerate the font cache:
+    #  flatpak list --columns=application | xargs -I %s -- flatpak run --command=fc-cache %s -f -v
+    system.fsPackages = [ pkgs.bindfs ];
+    fileSystems =
+      let
+        mkRoSymBind = path: {
+          device = path;
+          fsType = "fuse.bindfs";
+          options = [
+            "ro"
+            "resolve-symlinks"
+            "x-gvfs-hide"
+          ];
+        };
+        aggregatedIcons = pkgs.buildEnv {
+          name = "system-icons";
+          paths = with pkgs; [
+            (lib.mkIf config.aux.system.ui.gnome.enable gnome.gnome-themes-extra)
+            (lib.mkIf config.aux.system.ui.kde.enable kdePackages.breeze-icons)
+          ];
+          pathsToLink = [ "/share/icons" ];
+        };
+        aggregatedFonts = pkgs.buildEnv {
+          name = "system-fonts";
+          paths = config.fonts.packages;
+          pathsToLink = [ "/share/fonts" ];
+        };
+      in
+      {
+        "/usr/share/icons" = mkRoSymBind "${aggregatedIcons}/share/icons";
+        "/usr/local/share/fonts" = mkRoSymBind "${aggregatedFonts}/share/fonts";
+      };
+  };
+}