nixos/collectd: allow accessing the final package with applied plugins and minimalPackage (#506074)

nixos/modules/services/monitoring/collectd.nix

@@ -46,6 +46,20 @@ in
 
     package = lib.mkPackageOption pkgs "collectd" { };
 
+    finalPackage = lib.mkOption {
+      readOnly = true;
+      default = minimalPackage;
+      defaultText = lib.literalExpression ''
+        if config.services.collectd.buildMinimalPackage then
+          cfg.package.override {
+            enabledPlugins = [ "syslog" ] ++ builtins.attrNames cfg.plugins;
+          }
+        else
+          cfg.package
+      '';
+      description = "The final package being used after applying plugins and minimalPackage.";
+    };
+
     buildMinimalPackage = lib.mkOption {
       default = false;
       description = ''

pkgs/tools/system/collectd/default.nix

@@ -11,10 +11,10 @@
   flex,
   perl,
   nixosTests,
-  ...
-}@args:
+  enabledPlugins ? null,
+}:
 let
-  plugins = callPackage ./plugins.nix args;
+  plugins = callPackage ./plugins.nix { inherit enabledPlugins; };
 in
 stdenv.mkDerivation (finalAttrs: {
   pname = "collectd";

pkgs/tools/system/collectd/plugins.nix

@@ -45,7 +45,6 @@
   # Defaults to `null` for all supported plugins (except xen, which is marked as
   # insecure), otherwise a list of plugin names for a custom build
   enabledPlugins ? null,
-  ...
 }:
 
 let