feat: made impermanence create datasets for zfs and persistence

modules/nixos-modules/storage/impermanence.nix

@@ -1,33 +1,90 @@
-args @ {lib, ...}: let
-  impermanenceDatasetSubmodules = (import ./submodules/impermanenceDataset.nix) args;
+args @ {
+  lib,
+  config,
+  ...
+}: let
+  datasetSubmodules = (import ./submodules/dataset.nix) args;
+  impermanenceDatasetSubmodule = (import ./submodules/impermanenceDataset.nix) args;
+
+  permissionsToMode = permissions: let
+    permSetToDigit = permSet:
+      (
+        if permSet.read
+        then 4
+        else 0
+      )
+      + (
+        if permSet.write
+        then 2
+        else 0
+      )
+      + (
+        if permSet.execute
+        then 1
+        else 0
+      );
+
+    ownerDigit = permSetToDigit permissions.owner.permissions;
+    groupDigit = permSetToDigit permissions.group.permissions;
+    otherDigit = permSetToDigit permissions.other.permissions;
+  in
+    toString ownerDigit + toString groupDigit + toString otherDigit;
+
+  # Get the option names from both submodules to automatically determine which are impermanence-specific
+  regularDatasetEval = lib.evalModules {
+    modules = [datasetSubmodules];
+    specialArgs = args;
+  };
+  impermanenceDatasetEval = lib.evalModules {
+    modules = [impermanenceDatasetSubmodule];
+    specialArgs = args;
+  };
+
+  regularDatasetOptions = builtins.attrNames regularDatasetEval.options;
+  impermanenceDatasetOptions = builtins.attrNames impermanenceDatasetEval.options;
+
+  # Find options that are only in impermanence datasets (not in regular ZFS datasets)
+  impermanenceOnlyOptions = lib.lists.subtractLists regularDatasetOptions impermanenceDatasetOptions;
 in {
   options.storage = {
     impermanence = {
       enable = lib.mkEnableOption "should impermanence be enabled for this system";
-      # TODO: enable option implementation
-
-      # TODO: assertion that zfs needs to be enabled when impermanence is enabled
-
-      # TODO: datasets option that is a submodule that will be used to define what datasets to add to the storage system
-      #   We should by default create the `local`, `local/system/nix`, `local/system/root`, `persist` `persist/system/root`, and `persist/system/var/log` datasets
-      #   We should also create datasets for systemd modules that have have impermanence enabled for them
 
       datasets = lib.mkOption {
-        type = lib.types.attrsOf (lib.types.submodule impermanenceDatasetSubmodules);
+        type = lib.types.attrsOf (lib.types.submodule impermanenceDatasetSubmodule);
         default = {};
       };
-
-      # TODO: this should just live under home-manager.users.<user>.storage.impermanence
-      home-manager = lib.mkOption {
-        type = lib.types.attrsOf (lib.types.submodule ({name, ...}: {
-          enable = lib.mkEnableOption "should impermanence be enabled for this user";
-          # We should by default create the `local/home/${name}`, and `persist/home/${name}` datasets
-          datasets = lib.mkOption {
-            type = lib.types.attrsOf (lib.types.submodule impermanenceDatasetSubmodules);
-            default = {};
-          };
-        }));
-      };
     };
   };
+
+  config = lib.mkIf config.storage.impermanence.enable (lib.mkMerge [
+    {
+      environment.persistence =
+        lib.mapAttrs (datasetName: dataset: {
+          enable = true;
+          hideMounts = true;
+          directories = lib.mapAttrsToList (path: dirConfig: {
+            directory = path;
+            user = dirConfig.owner.name;
+            group = dirConfig.group.name;
+            mode = permissionsToMode dirConfig;
+          }) (lib.filterAttrs (_: dirConfig: dirConfig.enable) dataset.directories);
+          files = lib.mapAttrsToList (path: fileConfig: {
+            file = path;
+            user = fileConfig.owner.name;
+            group = fileConfig.group.name;
+            mode = permissionsToMode fileConfig;
+          }) (lib.filterAttrs (_: fileConfig: fileConfig.enable) dataset.files);
+        })
+        config.storage.impermanence.datasets;
+    }
+    (lib.mkIf config.storage.zfs.enable {
+      storage.zfs.datasets =
+        lib.mapAttrs (
+          datasetName: dataset:
+            builtins.removeAttrs dataset impermanenceOnlyOptions
+        )
+        config.storage.impermanence.datasets;
+    })
+  ]);
 }