[Core] Add method for setting span status (Azure#40703)

Spans started by `OpenTelemetryTracer` in core return an OpenTelemetry
span. The set_status on this method requires that a user imports
`opentelemetry` types for `StatusCode` enums.

We want to avoid SDK developers needing to import
`opentelemetry` in order to set a span status, however in all cases so
far where a user is setting a status, it's to set it to ERROR.  Here, we are adding a
utility method on the `OpenTelemetryTracer` class to enable setting an
error status on a provided span.

Signed-off-by: Paul Van Eck <[email protected]>

Author: pvaneck

sdk/core/azure-core/CHANGELOG.md

@@ -4,6 +4,8 @@
 
 ### Features Added
 
+- Added a `set_span_error_status` method to the `OpenTelemetryTracer` class. This method allows users to set the status of a span to `ERROR` after it has been created. #40703
+
 ### Breaking Changes
 
 ### Bugs Fixed

sdk/core/azure-core/azure/core/tracing/opentelemetry.py

@@ -12,6 +12,7 @@
     Span,
     SpanKind as OpenTelemetrySpanKind,
     Link as OpenTelemetryLink,
+    StatusCode,
 )
 from opentelemetry.trace.propagation import get_current_span as get_current_span_otel
 from opentelemetry.propagate import extract, inject
@@ -161,6 +162,17 @@ def use_span(cls, span: Span, *, end_on_exit: bool = True) -> Iterator[Span]:
         ) as active_span:
             yield active_span
 
+    @staticmethod
+    def set_span_error_status(span: Span, description: Optional[str] = None) -> None:
+        """Set the status of a span to ERROR with the provided description, if any.
+
+        :param span: The span to set the ERROR status on.
+        :type span: ~opentelemetry.trace.Span
+        :param description: An optional description of the error.
+        :type description: str
+        """
+        span.set_status(StatusCode.ERROR, description=description)
+
     def _parse_links(self, links: Optional[Sequence[Link]]) -> Optional[Sequence[OpenTelemetryLink]]:
         if not links:
             return None

sdk/core/azure-core/tests/test_tracer_otel.py

@@ -354,3 +354,25 @@ def test_tracer_caching_different_args():
 
     assert tracer1 is tracer2
     assert tracer1 is not tracer3
+
+
+def test_tracer_set_span_error(tracing_helper):
+    """Test that the tracer's set_span_status method works correctly."""
+    tracer = get_tracer()
+    assert tracer
+
+    with tracer.start_as_current_span(name="ok-span") as span:
+        tracer.set_span_error_status(span)
+
+    with tracer.start_as_current_span(name="ok-span") as span:
+        tracer.set_span_error_status(span, "This is an error")
+
+    # Verify status on finished spans
+    finished_spans = tracing_helper.exporter.get_finished_spans()
+    assert len(finished_spans) == 2
+
+    assert finished_spans[0].status.status_code == OtelStatusCode.ERROR
+    assert finished_spans[0].status.description is None
+
+    assert finished_spans[1].status.status_code == OtelStatusCode.ERROR
+    assert finished_spans[1].status.description == "This is an error"