feat(otel): env variable for disabling llm_request and llm_response in spans

The default without the variable set is to keep the content in spans to keep backward compatible behavior for existing users.

This allows to enable tracing without potential PII data from request and response. Google GenAI instrumentation lib requires an explicit opt-in to enable request and response content - see https://github.com/open-telemetry/opentelemetry-python-contrib/tree/main/instrumentation-genai/opentelemetry-instrumentation-google-genai#enabling-message-content.

PiperOrigin-RevId: 820351154

tests/unittests/telemetry/test_spans.py

@@ -13,6 +13,7 @@
 # limitations under the License.
 
 import json
+import os
 from typing import Any
 from typing import Dict
 from typing import Optional
@@ -23,6 +24,7 @@ from google.adk.agents.llm_agent import LlmAgent
 from google.adk.models.llm_request import LlmRequest
 from google.adk.models.llm_response import LlmResponse
 from google.adk.sessions.in_memory_session_service import InMemorySessionService
+from google.adk.telemetry.tracing import ADK_CAPTURE_MESSAGE_CONTENT_IN_SPANS
 from google.adk.telemetry.tracing import trace_agent_invocation
 from google.adk.telemetry.tracing import trace_call_llm
 from google.adk.telemetry.tracing import trace_merged_tool_calls
@@ -371,3 +373,147 @@ def test_trace_merged_tool_calls_sets_correct_attributes(
       expected_calls, any_order=True
   )
   mock_event_fixture.model_dumps_json.assert_called_once_with(exclude_none=True)
+
+
+@pytest.mark.asyncio
+async def test_call_llm_disabling_request_response_content(
+    monkeypatch, mock_span_fixture
+):
+  """Test trace_call_llm doesn't set request and response attributes if env is set to false"""
+  # Arrange
+  monkeypatch.setenv(ADK_CAPTURE_MESSAGE_CONTENT_IN_SPANS, 'false')
+  monkeypatch.setattr(
+      'opentelemetry.trace.get_current_span', lambda: mock_span_fixture
+  )
+
+  agent = LlmAgent(name='test_agent')
+  invocation_context = await _create_invocation_context(agent)
+  llm_request = LlmRequest(
+      model='gemini-pro',
+      contents=[
+          types.Content(
+              role='user',
+              parts=[types.Part(text='Hello, how are you?')],
+          ),
+      ],
+  )
+  llm_response = LlmResponse(
+      turn_complete=True,
+      finish_reason=types.FinishReason.STOP,
+  )
+
+  # Act
+  trace_call_llm(invocation_context, 'test_event_id', llm_request, llm_response)
+
+  # Assert
+  assert not any(
+      call_obj.args[0] == 'gcp.vertex.agent.llm_request'
+      and call_obj.args[1] != {}
+      for call_obj in mock_span_fixture.set_attribute.call_args_list
+  ), "Attribute 'gcp.vertex.agent.llm_request' was incorrectly set on the span."
+
+  assert not any(
+      call_obj.args[0] == 'gcp.vertex.agent.llm_response'
+      and call_obj.args[1] != {}
+      for call_obj in mock_span_fixture.set_attribute.call_args_list
+  ), (
+      "Attribute 'gcp.vertex.agent.llm_response' was incorrectly set on the"
+      ' span.'
+  )
+
+
+def test_trace_tool_call_disabling_request_response_content(
+    monkeypatch,
+    mock_span_fixture,
+    mock_tool_fixture,
+    mock_event_fixture,
+):
+  """Test trace_tool_call doesn't set request and response attributes if env is set to false"""
+  # Arrange
+  monkeypatch.setenv(ADK_CAPTURE_MESSAGE_CONTENT_IN_SPANS, 'false')
+  monkeypatch.setattr(
+      'opentelemetry.trace.get_current_span', lambda: mock_span_fixture
+  )
+
+  test_args: Dict[str, Any] = {'query': 'details', 'id_list': [1, 2, 3]}
+  test_tool_call_id: str = 'tool_call_id_002'
+  test_event_id: str = 'event_id_dict_002'
+  dict_function_response: Dict[str, Any] = {
+      'data': 'structured_data',
+      'count': 5,
+  }
+
+  mock_event_fixture.id = test_event_id
+  mock_event_fixture.content = types.Content(
+      role='user',
+      parts=[
+          types.Part(
+              function_response=types.FunctionResponse(
+                  id=test_tool_call_id,
+                  name='test_function_1',
+                  response=dict_function_response,
+              )
+          ),
+      ],
+  )
+
+  # Act
+  trace_tool_call(
+      tool=mock_tool_fixture,
+      args=test_args,
+      function_response_event=mock_event_fixture,
+  )
+
+  # Assert
+  assert not any(
+      call_obj.args[0] == 'gcp.vertex.agent.tool_call_args'
+      and call_obj.args[1] != {}
+      for call_obj in mock_span_fixture.set_attribute.call_args_list
+  ), (
+      "Attribute 'gcp.vertex.agent.tool_call_args' was incorrectly set on the"
+      ' span.'
+  )
+
+  assert not any(
+      call_obj.args[0] == 'gcp.vertex.agent.tool_response'
+      and call_obj.args[1] != {}
+      for call_obj in mock_span_fixture.set_attribute.call_args_list
+  ), (
+      "Attribute 'gcp.vertex.agent.tool_response' was incorrectly set on the"
+      ' span.'
+  )
+
+
+def test_trace_merged_tool_disabling_request_response_content(
+    monkeypatch,
+    mock_span_fixture,
+    mock_event_fixture,
+):
+  """Test trace_merged_tool doesn't set request and response attributes if env is set to false"""
+  # Arrange
+  monkeypatch.setenv(ADK_CAPTURE_MESSAGE_CONTENT_IN_SPANS, 'false')
+  monkeypatch.setattr(
+      'opentelemetry.trace.get_current_span', lambda: mock_span_fixture
+  )
+
+  test_response_event_id = 'merged_evt_id_001'
+  custom_event_json_output = (
+      '{"custom_event_payload": true, "details": "merged_details"}'
+  )
+  mock_event_fixture.model_dumps_json.return_value = custom_event_json_output
+
+  # Act
+  trace_merged_tool_calls(
+      response_event_id=test_response_event_id,
+      function_response_event=mock_event_fixture,
+  )
+
+  # Assert
+  assert not any(
+      call_obj.args[0] == 'gcp.vertex.agent.tool_response'
+      and call_obj.args[1] != {}
+      for call_obj in mock_span_fixture.set_attribute.call_args_list
+  ), (
+      "Attribute 'gcp.vertex.agent.tool_response' was incorrectly set on the"
+      ' span.'
+  )