added stuff

nyx/modules/options/system/impermanence.nix

@@ -0,0 +1,87 @@
+{
+  config,
+  lib,
+  ...
+}: let
+  inherit (lib) mkEnableOption mkOption literalExpression;
+
+  cfg = config.modules.system.impermanence;
+in {
+  options.modules.system.impermanence = {
+    enable = mkOption {
+      default = cfg.root.enable || cfg.home.enable;
+      readOnly = true;
+      description = ''
+        Internal option for deciding if Impermanence module is enabled
+        based on the values of `modules.system.impermanence.root.enable`
+        and `modules.system.impermanence.home.enable`.
+      '';
+    };
+
+    root = {
+      enable = mkEnableOption ''
+        the Impermanence module for persisting important state directories.
+        By default, Impermanence will not touch user's $HOME, which is not
+        ephemeral unlike root.
+      '';
+
+      extraFiles = mkOption {
+        default = [];
+        example = literalExpression ''["/etc/nix/id_rsa"]'';
+        description = ''
+          Additional files in the root to link to persistent storage.
+        '';
+      };
+
+      extraDirectories = mkOption {
+        default = [];
+        example = literalExpression ''["/var/lib/libvirt"]'';
+        description = ''
+          Additional directories in the root to link to persistent
+          storage.
+        '';
+      };
+    };
+
+    home = {
+      enable = mkEnableOption ''
+        the Impermanence module for persisting important state directories.
+        This option will also make user's home ephemeral, on top of the root subvolume
+      '';
+
+      mountDotfiles = mkOption {
+        default = true;
+        description = ''
+          Whether the repository with my configuration flake should be bound to a location
+          in $HOME after a rebuild. It will symlink ''${self} to ~/.config/nyx where I
+          usually put my configuration files
+        '';
+      };
+
+      extraFiles = mkOption {
+        default = [];
+        example = literalExpression ''
+          [
+            ".gnupg/pubring.kbx"
+            ".gnupg/sshcontrol"
+            ".gnupg/trustdb.gpg"
+            ".gnupg/random_seed"
+          ]
+        '';
+        description = ''
+          Additional files in the home directory to link to persistent
+          storage.
+        '';
+      };
+
+      extraDirectories = mkOption {
+        default = [];
+        example = literalExpression ''[".config/gsconnect"]'';
+        description = ''
+          Additional directories in the home directory to link to
+          persistent storage.
+        '';
+      };
+    };
+  };
+}