[ATO-2105] Implement functionality to create custom spans

changelog/1075.improvement.md

@@ -0,0 +1 @@
+Implement functionality that enables creating additional spans within custom actions.

rasa_sdk/tracing/instrumentation/instrumentation.py

@@ -17,6 +17,7 @@
 from rasa_sdk.executor import ActionExecutor
 from rasa_sdk.forms import ValidationAction
 from rasa_sdk.tracing.instrumentation import attribute_extractors
+from rasa_sdk.tracing.tracer_register import ActionExecutorTracerRegister
 
 # The `TypeVar` representing the return type for a function to be wrapped.
 S = TypeVar("S")
@@ -132,13 +133,15 @@ def instrument(
     if action_executor_class is not None and not class_is_instrumented(
         action_executor_class
     ):
+        tracer = tracer_provider.get_tracer(action_executor_class.__module__)
         _instrument_method(
-            tracer_provider.get_tracer(action_executor_class.__module__),
+            tracer,
             action_executor_class,
             "run",
             attribute_extractors.extract_attrs_for_action_executor,
         )
         mark_class_as_instrumented(action_executor_class)
+        ActionExecutorTracerRegister().register_tracer(tracer)
 
     if validation_action_class is not None and not class_is_instrumented(
         validation_action_class

rasa_sdk/tracing/tracer_register.py

@@ -0,0 +1,23 @@
+from typing import Optional
+from rasa_sdk.utils import Singleton
+from opentelemetry.trace import Tracer
+
+
+class ActionExecutorTracerRegister(metaclass=Singleton):
+    """Represents a provider for ActionExecutor tracer."""
+
+    tracer: Optional[Tracer] = None
+
+    def register_tracer(self, tracer: Tracer) -> None:
+        """Register an ActionExecutor tracer.
+        Args:
+            trace: The tracer to register.
+        """
+        self.tracer = tracer
+
+    def get_tracer(self) -> Optional[Tracer]:
+        """Get the ActionExecutor tracer.
+        Returns:
+            The tracer.
+        """
+        return self.tracer

rasa_sdk/utils.py

@@ -46,6 +46,28 @@ class Button(dict):
     pass
 
 
+class Singleton(type):
+    """Singleton metaclass."""
+
+    _instances: Dict[Any, Any] = {}
+
+    def __call__(cls, *args: Any, **kwargs: Any) -> Any:
+        """Call the class.
+
+        Args:
+            *args: Arguments.
+            **kwargs: Keyword arguments.
+        """
+        if cls not in cls._instances:
+            cls._instances[cls] = super(Singleton, cls).__call__(*args, **kwargs)
+
+        return cls._instances[cls]
+
+    def clear(cls) -> None:
+        """Clear the class."""
+        cls._instances = {}
+
+
 def all_subclasses(cls: Any) -> List[Any]:
     """Returns all known (imported) subclasses of a class."""
     return cls.__subclasses__() + [

tests/tracing/instrumentation/test_action_executor.py

@@ -1,13 +1,17 @@
-from typing import Any, Dict, Sequence, Text, Optional
-
 import pytest
+
+from typing import Any, Dict, Sequence, Text, Optional
+from unittest.mock import Mock
+from pytest import MonkeyPatch
 from opentelemetry.sdk.trace import ReadableSpan, TracerProvider
 from opentelemetry.sdk.trace.export.in_memory_span_exporter import InMemorySpanExporter
+from opentelemetry import trace
 
 from rasa_sdk.tracing.instrumentation import instrumentation
 from tests.tracing.instrumentation.conftest import MockActionExecutor
 from rasa_sdk.types import ActionCall
 from rasa_sdk import Tracker
+from rasa_sdk.tracing.tracer_register import ActionExecutorTracerRegister
 
 
 @pytest.mark.parametrize(
@@ -56,3 +60,31 @@ async def test_tracing_action_executor_run(
     assert captured_span.name == "MockActionExecutor.run"
 
     assert captured_span.attributes == expected
+
+
+def test_instrument_action_executor_run_registers_tracer(
+    tracer_provider: TracerProvider, monkeypatch: MonkeyPatch
+) -> None:
+    component_class = MockActionExecutor
+
+    mock_tracer = trace.get_tracer(__name__)
+
+    register_tracer_mock = Mock()
+    get_tracer_mock = Mock(return_value=mock_tracer)
+
+    monkeypatch.setattr(
+        ActionExecutorTracerRegister, "register_tracer", register_tracer_mock()
+    )
+    monkeypatch.setattr(ActionExecutorTracerRegister, "get_tracer", get_tracer_mock)
+
+    instrumentation.instrument(
+        tracer_provider,
+        action_executor_class=component_class,
+    )
+    register_tracer_mock.assert_called_once()
+
+    provider = ActionExecutorTracerRegister()
+    tracer = provider.get_tracer()
+
+    assert tracer is not None
+    assert tracer == mock_tracer

tests/tracing/test_tracer_register.py

@@ -0,0 +1,21 @@
+from rasa_sdk.tracing.tracer_register import ActionExecutorTracerRegister
+from opentelemetry import trace
+
+
+def test_tracer_register_is_singleton() -> None:
+    tracer_register_1 = ActionExecutorTracerRegister()
+    tracer_register_2 = ActionExecutorTracerRegister()
+
+    assert tracer_register_1 is tracer_register_2
+    assert tracer_register_1.tracer is tracer_register_2.tracer
+
+
+def test_trace_register() -> None:
+    tracer_register = ActionExecutorTracerRegister()
+    assert tracer_register.get_tracer() is None
+
+    tracer = trace.get_tracer(__name__)
+    tracer_register.register_tracer(tracer)
+
+    assert tracer_register.tracer == tracer
+    assert tracer_register.get_tracer() == tracer