nix-flakes.nix: inherit from upstream nix-flakes.nix

Author: ShamrockLee

modules/environment/nix-flakes.nix

@@ -5,7 +5,7 @@
 # (Copyright (c) 2003-2022 Eelco Dolstra and the Nixpkgs/NixOS contributors,
 # licensed under MIT License as well)
 
-{ config, lib, pkgs, ... }:
+{ config, lib, pkgs, nixpkgs, ... }:
 
 with lib;
 
@@ -14,79 +14,8 @@ let
 in
 
 {
-  ###### interface
-
-  options = {
-    nix = {
-      registry = mkOption {
-        type = types.attrsOf (types.submodule (
-          let
-            referenceAttrs = with types; attrsOf (oneOf [
-              str
-              int
-              bool
-              package
-            ]);
-          in
-          { config, name, ... }:
-          {
-            options = {
-              from = mkOption {
-                type = referenceAttrs;
-                example = { type = "indirect"; id = "nixpkgs"; };
-                description = "The flake reference to be rewritten.";
-              };
-              to = mkOption {
-                type = referenceAttrs;
-                example = { type = "github"; owner = "my-org"; repo = "my-nixpkgs"; };
-                description = "The flake reference <option>from</option> is rewritten to.";
-              };
-              flake = mkOption {
-                type = types.nullOr types.attrs;
-                default = null;
-                example = literalExpression "nixpkgs";
-                description = ''
-                  The flake input <option>from</option> is rewritten to.
-                '';
-              };
-              exact = mkOption {
-                type = types.bool;
-                default = true;
-                description = ''
-                  Whether the <option>from</option> reference needs to match exactly. If set,
-                  a <option>from</option> reference like <literal>nixpkgs</literal> does not
-                  match with a reference like <literal>nixpkgs/nixos-20.03</literal>.
-                '';
-              };
-            };
-            config = {
-              from = mkDefault { type = "indirect"; id = name; };
-              to = mkIf (config.flake != null) (mkDefault
-                {
-                  type = "path";
-                  path = config.flake.outPath;
-                } // filterAttrs
-                (n: _: n == "lastModified" || n == "rev" || n == "revCount" || n == "narHash")
-                config.flake);
-            };
-          }
-        ));
-        default = { };
-        description = "A system-wide flake registry.";
-      };
-    };
-  };
-
-
-  ###### implementation
-
-  config = {
-    environment.etc = {
-      "nix/registry.json".text = builtins.toJSON {
-        version = 2;
-        flakes = mapAttrsToList (_n: v: { inherit (v) from to exact; }) cfg.registry;
-      };
-    };
-  };
-
+  imports = [
+    # Use options and config from upstream nix-flakes.nix
+    "${nixpkgs}nixos/modules/config/nix-flakes.nix"
+  ];
 }