Conditionally create server spans for falcon

CHANGELOG.md

@@ -13,7 +13,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#817](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/817))
 - `opentelemetry-instrumentation-kafka-python` added kafka-python module instrumentation.
   ([#814](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/814))
-
+- `opentelemetry-instrumentation-falcon` Falcon: Conditionally create SERVER spans
+  ([#867](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/867))
 ### Fixed
 
 - `opentelemetry-instrumentation-django` Django: Conditionally create SERVER spans

instrumentation/opentelemetry-instrumentation-falcon/src/opentelemetry/instrumentation/falcon/__init__.py

@@ -109,6 +109,7 @@ def response_hook(span, req, resp):
 from opentelemetry.instrumentation.utils import (
     extract_attributes_from_object,
     http_status_to_status_code,
+    get_token_context_span_kind
 )
 from opentelemetry.propagate import extract
 from opentelemetry.semconv.trace import SpanAttributes
@@ -195,12 +196,15 @@ def __call__(self, env, start_response):
 
         start_time = _time_ns()
 
-        token = context.attach(extract(env, getter=otel_wsgi.wsgi_getter))
+        token, ctx, span_kind = get_token_context_span_kind(env, getter=otel_wsgi.wsgi_getter)
+
         span = self._tracer.start_span(
             otel_wsgi.get_default_span_name(env),
-            kind=trace.SpanKind.SERVER,
+            context=ctx,
+            kind=span_kind,
             start_time=start_time,
         )
+
         if span.is_recording():
             attributes = otel_wsgi.collect_request_attributes(env)
             for key, value in attributes.items():
@@ -216,7 +220,8 @@ def _start_response(status, response_headers, *args, **kwargs):
                 status, response_headers, *args, **kwargs
             )
             activation.__exit__(None, None, None)
-            context.detach(token)
+            if token is not None:
+                context.detach(token)
             return response
 
         try:
@@ -227,7 +232,8 @@ def _start_response(status, response_headers, *args, **kwargs):
                 exc,
                 getattr(exc, "__traceback__", None),
             )
-            context.detach(token)
+            if token is not None:
+                context.detach(token)
             raise
 
 

instrumentation/opentelemetry-instrumentation-falcon/tests/test_falcon.py

@@ -16,6 +16,7 @@
 
 from falcon import testing
 
+from opentelemetry import trace
 from opentelemetry.instrumentation.falcon import FalconInstrumentor
 from opentelemetry.instrumentation.propagators import (
     TraceResponsePropagator,
@@ -264,3 +265,18 @@ def test_hooks(self):
         self.assertEqual(
             span.attributes["request_hook_attr"], "value from hook"
         )
+
+
+class TestFalconInstrumentationWrappedWithOtherFramework(TestFalconBase):
+    def test_mark_span_internal_in_presence_of_span_from_other_framework(self):
+        tracer = trace.get_tracer(__name__)
+        with tracer.start_as_current_span(
+            "test", kind=trace.SpanKind.SERVER
+        ) as parent_span:
+            self.client().simulate_request(method="GET", path="/hello")
+            span = self.memory_exporter.get_finished_spans()[0]
+            assert span.status.is_ok
+            self.assertEqual(trace.SpanKind.INTERNAL, span.kind)
+            self.assertEqual(
+                span.parent.span_id, parent_span.get_span_context().span_id
+            )

opentelemetry-instrumentation/src/opentelemetry/instrumentation/utils.py

@@ -14,12 +14,14 @@
 
 from typing import Dict, Sequence
 
+from opentelemetry import context, trace
 from wrapt import ObjectProxy
 
 # pylint: disable=unused-import
 # pylint: disable=E0611
 from opentelemetry.context import _SUPPRESS_INSTRUMENTATION_KEY  # noqa: F401
 from opentelemetry.trace import StatusCode
+from opentelemetry.propagate import extract
 
 
 def extract_attributes_from_object(
@@ -67,3 +69,29 @@ def unwrap(obj, attr: str):
     func = getattr(obj, attr, None)
     if func and isinstance(func, ObjectProxy) and hasattr(func, "__wrapped__"):
         setattr(obj, attr, func.__wrapped__)
+
+
+def get_token_context_span_kind(env, getter):
+    """Based on presence of active span, extracts context and initializes token and span_kind 
+
+    Args:
+        env : object which contains values that are
+            used to construct a Context. This object
+            must be paired with an appropriate getter
+            which understands how to extract a value from it.
+        getter : an object which contains a get function that can retrieve zero
+            or more values from the carrier and a keys function that can get all the keys
+            from carrier. 
+    """
+
+    token = ctx = span_kind = None
+
+    if trace.get_current_span() is trace.INVALID_SPAN:
+        ctx = extract(env, getter=getter)
+        token = context.attach(ctx)
+        span_kind = trace.SpanKind.SERVER
+    else:
+        ctx = context.get_current()
+        span_kind = trace.SpanKind.INTERNAL
+
+    return token, ctx, span_kind