[devkit][bugfix] Add check for trace.NoOpTracerProvider to avoid cr…

…ash (#3407)

# Description

In some cases (we have observed in runtime scenario, related to mlflow),
tracer provider can be set as `trace.NoOpTracerProvider`, which does not
have method `add_span_processor` and lead to error. This PR adds a check
on that to avoid such crash.

# All Promptflow Contribution checklist:
- [x] **The pull request does not introduce [breaking changes].**
- [x] **CHANGELOG is updated for new features, bug fixes or other
significant changes.**
- [x] **I have read the [contribution guidelines](../CONTRIBUTING.md).**
- [ ] **Create an issue and link to the pull request to get dedicated
review from promptflow team. Learn more: [suggested
workflow](../CONTRIBUTING.md#suggested-workflow).**

## General Guidelines and Best Practices
- [x] Title of the pull request is clear and informative.
- [x] There are a small number of commits, each of which have an
informative message. This means that previously merged commits do not
appear in the history of the PR. For more information on cleaning up the
commits in your PR, [see this
page](https://github.com/Azure/azure-powershell/blob/master/documentation/development-docs/cleaning-up-commits.md).

### Testing Guidelines
- [x] Pull request includes test coverage for the included changes.

src/promptflow-devkit/CHANGELOG.md

@@ -1,5 +1,10 @@
 # promptflow-devkit package
 
+## v1.13.0 (Upcoming)
+
+### Bugs Fixed
+- Fix incompatibility with `trace.NoOpTracerProvider` when set exporter to prompt flow service.
+
 ## v1.12.0 (2024.06.11)
 
 ### Improvements

src/promptflow-devkit/promptflow/_sdk/_tracing.py

@@ -550,6 +550,10 @@ def setup_exporter_to_pfs() -> None:
         tracer_provider: TracerProvider = trace.get_tracer_provider()
         if is_exporter_setup_skipped():
             _logger.debug("exporter setup is skipped according to environment variable.")
+        elif isinstance(tracer_provider, trace.NoOpTracerProvider):
+            _logger.warning(
+                "tracer provider is set to NoOpTracerProvider, skip setting exporter to prompt flow service."
+            )
         else:
             if not getattr(tracer_provider, TRACER_PROVIDER_PFS_EXPORTER_SET_ATTR, False):
                 _logger.info("have not set exporter to prompt flow service, will set it...")

src/promptflow-devkit/tests/sdk_cli_test/unittests/test_trace.py

@@ -33,7 +33,7 @@
     TRACE_LIST_DEFAULT_LIMIT,
     ContextAttributeKey,
 )
-from promptflow._sdk._tracing import start_trace_with_devkit
+from promptflow._sdk._tracing import setup_exporter_to_pfs, start_trace_with_devkit
 from promptflow._sdk._utilities.tracing_utils import WorkspaceKindLocalCache, append_conditions, parse_protobuf_span
 from promptflow.client import PFClient
 from promptflow.exceptions import UserErrorException
@@ -196,6 +196,20 @@ def test_pfs_invocation_failed_in_start_trace(self):
             start_trace_with_devkit(collection=str(uuid.uuid4()))
             assert monitor_func.call_count == 0
 
+    @pytest.mark.usefixtures("reset_tracer_provider")
+    def test_no_op_tracer_provider(self, monkeypatch: pytest.MonkeyPatch, caplog: pytest.LogCaptureFixture):
+        # logger with "promptflow." prefix cannot be captured by caplog, so patch the logger for this test
+        with patch("promptflow._sdk._tracing._logger", logging.getLogger(__name__)):
+            with caplog.at_level(level=logging.WARNING):
+                monkeypatch.setenv(OTEL_EXPORTER_OTLP_ENDPOINT, "http://dummy-endpoint")
+                trace.set_tracer_provider(trace.NoOpTracerProvider())
+                setup_exporter_to_pfs()
+                monkeypatch.delenv(OTEL_EXPORTER_OTLP_ENDPOINT)
+            assert (
+                "tracer provider is set to NoOpTracerProvider, skip setting exporter to prompt flow service."
+                in caplog.text
+            )
+
 
 @pytest.mark.unittest
 @pytest.mark.sdk_test

src/promptflow/CHANGELOG.md

@@ -1,4 +1,10 @@
 # Release History
+
+## v1.13.0 (Upcoming)
+
+### Bugs Fixed
+- Fix incompatibility with `trace.NoOpTracerProvider` when set exporter to prompt flow service.
+
 ## v1.12.0 (2024.06.11)
 
 ### Bugs fixed