Fixed missing requester for spawned threads of SystemClient

CHANGELOG.rst

@@ -6,6 +6,8 @@ Brewtils Changelog
 TBD
 
 - Expanded PublishClient to support Registering and Unregistering commands to Topics after a plugin has been initialized
+- Fixed bug where threading a SystemClient within a plugin lost current_request context and failed to map `requester`, 
+  SystemClient will still drop the current_request context,but the requester field can be provided via `_requester`
 
 3.27.1
 ------

brewtils/rest/system_client.py

@@ -595,13 +595,16 @@ def _construct_bg_request(self, **kwargs):
         publish = kwargs.pop("_publish", None)
         topic = kwargs.pop("_topic", None)
         propagate = kwargs.pop("_propagate", None)
+        requester = kwargs.pop("_requester", None)
 
-        if parent:
+        if (
+            not requester
+            and parent
+            and getattr(brewtils.plugin.request_context, "current_request", None)
+        ):
             requester = getattr(
                 brewtils.plugin.request_context.current_request, "requester", None
             )
-        else:
-            requester = None
 
         if system_display:
             metadata["system_display_name"] = system_display

test/rest/system_client_test.py

@@ -304,6 +304,52 @@ def test_missing_field(self, monkeypatch, client, remove_kwarg):
         with pytest.raises(ValidationError):
             client._construct_bg_request(**kwargs)
 
+    def test_requester_field(self, monkeypatch, client):
+        monkeypatch.setattr(client, "_resolve_parameters", Mock())
+
+        kwargs = {
+            "_command": "",
+            "_system_name": "",
+            "_system_version": "",
+            "_instance_name": "",
+            "_requester": "test",
+        }
+
+        request = client._construct_bg_request(**kwargs)
+        assert request.requester == "test"
+
+    def test_requester_from_parent_field(self, monkeypatch, client):
+        monkeypatch.setattr(client, "_resolve_parameters", Mock())
+        monkeypatch.setattr(
+            brewtils.plugin,
+            "request_context",
+            Mock(current_request=Mock(id="1", requester="test")),
+        )
+
+        kwargs = {
+            "_command": "",
+            "_system_name": "",
+            "_system_version": "",
+            "_instance_name": "",
+        }
+
+        request = client._construct_bg_request(**kwargs)
+        assert request.requester == "test"
+
+    def test_no_requester_from_provided_parent(self, monkeypatch, client):
+        monkeypatch.setattr(client, "_resolve_parameters", Mock())
+
+        kwargs = {
+            "_command": "",
+            "_system_name": "",
+            "_system_version": "",
+            "_instance_name": "",
+            "_parent": Mock(id="1"),
+        }
+
+        request = client._construct_bg_request(**kwargs)
+        assert request.requester is None
+
     def test_positional_parameter(self, client, easy_client, mock_success):
         easy_client.create_request.return_value = mock_success