Split configuration into reusable modules

modules/darwin/mac-portable.nix

@@ -0,0 +1,58 @@
+{ pkgs, primaryUser, ... }:
+{
+  nixpkgs.config.allowUnfree = true;
+
+  system.primaryUser = primaryUser;
+  users.users.${primaryUser} = {
+    home = "/Users/${primaryUser}";
+    shell = pkgs.zsh;
+  };
+
+  security.pam.services.sudo_local.touchIdAuth = true;
+
+  system = {
+    startup.chime = false;
+
+    defaults = {
+      loginwindow = {
+        GuestEnabled = false;
+        DisableConsoleAccess = true;
+      };
+
+      finder = {
+        AppleShowAllFiles = true; # hidden files
+        AppleShowAllExtensions = true; # file extensions
+        _FXShowPosixPathInTitle = true; # title bar full path
+        ShowPathbar = true; # breadcrumb nav at bottom
+        ShowStatusBar = true; # file count & disk space
+      };
+
+      NSGlobalDomain = {
+        NSAutomaticSpellingCorrectionEnabled = false;
+        NSAutomaticCapitalizationEnabled = false;
+        NSAutomaticPeriodSubstitutionEnabled = false;
+        NSAutomaticWindowAnimationsEnabled = false;
+      };
+    };
+  };
+
+  # Create /etc/zshrc that loads the nix-darwin environment.
+  programs.zsh.enable = true;
+
+  nix-homebrew = {
+    # Initial install of homebrew.
+    enable = true;
+    user = primaryUser;
+    autoMigrate = true;
+  };
+  homebrew = {
+    enable = true;
+    onActivation = {
+      cleanup = "zap";
+      autoUpdate = false;
+      upgrade = true;
+    };
+  };
+
+  system.stateVersion = 6; # Never change.
+}