Add nodes and privileges to nodeinfo

I didn't add it to /api/v1/instance
I was wondering if I should, but since it e.g. also didn't show staff, it felt better not to

lib/pleroma/web/nodeinfo/nodeinfo.ex

@@ -49,6 +49,10 @@ defmodule Pleroma.Web.Nodeinfo.Nodeinfo do
           enabled: false
         },
         staffAccounts: staff_accounts,
+        roles: %{
+          admin: Config.get([:instance, :admin_privileges]),
+          moderator: Config.get([:instance, :moderator_privileges])
+        },
         federation: federation,
         pollLimits: Config.get([:instance, :poll_limits]),
         postFormats: Config.get([:instance, :allowed_post_formats]),

test/pleroma/web/node_info_test.exs

@@ -3,7 +3,7 @@
 # SPDX-License-Identifier: AGPL-3.0-only
 
 defmodule Pleroma.Web.NodeInfoTest do
-  use Pleroma.Web.ConnCase
+  use Pleroma.Web.ConnCase, async: false
 
   import Pleroma.Factory
 
@@ -40,6 +40,19 @@ defmodule Pleroma.Web.NodeInfoTest do
     assert admin.ap_id in result["metadata"]["staffAccounts"]
   end
 
+  test "nodeinfo shows roles and privileges", %{conn: conn} do
+    clear_config([:instance, :moderator_privileges], [:cofe])
+    clear_config([:instance, :admin_privileges], [:suya, :cofe])
+
+    conn =
+      conn
+      |> get("/nodeinfo/2.1.json")
+
+    assert result = json_response(conn, 200)
+
+    assert %{"admin" => ["suya", "cofe"], "moderator" => ["cofe"]} == result["metadata"]["roles"]
+  end
+
   test "nodeinfo shows restricted nicknames", %{conn: conn} do
     conn =
       conn