feat: Enable passing explicit urls to exclude from instrumentation in fastapi

Author: cdvv7788

instrumentation/opentelemetry-instrumentation-fastapi/README.rst

@@ -51,6 +51,11 @@ Usage
 
     FastAPIInstrumentor.instrument_app(app)
 
+You can also pass the list of urls to exclude explicitly to the instrumentation call:
+
+.. code-block:: python
+    from opentelemetry.util.http import ExcludeList
+    FastAPIInstrumentor.instrument_app(app, ExcludeList("client/.*/info,healthcheck"))
 
 References
 ----------

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

@@ -32,13 +32,19 @@ class FastAPIInstrumentor(BaseInstrumentor):
     _original_fastapi = None
 
     @staticmethod
-    def instrument_app(app: fastapi.FastAPI, tracer_provider=None):
-        """Instrument an uninstrumented FastAPI application.
-        """
+    def instrument_app(
+        app: fastapi.FastAPI,
+        tracer_provider=None,
+        excluded_urls=None,
+    ):
+        """Instrument an uninstrumented FastAPI application."""
         if not getattr(app, "is_instrumented_by_opentelemetry", False):
+            if excluded_urls is None:
+                excluded_urls = _excluded_urls
+
             app.add_middleware(
                 OpenTelemetryMiddleware,
-                excluded_urls=_excluded_urls,
+                excluded_urls=excluded_urls,
                 span_details_callback=_get_route_details,
                 tracer_provider=tracer_provider,
             )
@@ -47,6 +53,7 @@ def instrument_app(app: fastapi.FastAPI, tracer_provider=None):
     def _instrument(self, **kwargs):
         self._original_fastapi = fastapi.FastAPI
         _InstrumentedFastAPI._tracer_provider = kwargs.get("tracer_provider")
+        _InstrumentedFastAPI._excluded_urls = kwargs.get("excluded_urls")
         fastapi.FastAPI = _InstrumentedFastAPI
 
     def _uninstrument(self, **kwargs):
@@ -55,12 +62,18 @@ def _uninstrument(self, **kwargs):
 
 class _InstrumentedFastAPI(fastapi.FastAPI):
     _tracer_provider = None
+    _excluded_urls = None
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
+        excluded_urls = (
+            _InstrumentedFastAPI._excluded_urls
+            if _InstrumentedFastAPI._excluded_urls is not None
+            else _excluded_urls
+        )
         self.add_middleware(
             OpenTelemetryMiddleware,
-            excluded_urls=_excluded_urls,
+            excluded_urls=excluded_urls,
             span_details_callback=_get_route_details,
             tracer_provider=_InstrumentedFastAPI._tracer_provider,
         )

instrumentation/opentelemetry-instrumentation-fastapi/tests/test_fastapi_instrumentation.py

@@ -22,7 +22,7 @@
 from opentelemetry.sdk.resources import Resource
 from opentelemetry.semconv.trace import SpanAttributes
 from opentelemetry.test.test_base import TestBase
-from opentelemetry.util.http import get_excluded_urls
+from opentelemetry.util.http import get_excluded_urls, ExcludeList
 
 
 class TestFastAPIManualInstrumentation(TestBase):
@@ -31,6 +31,17 @@ def _create_app(self):
         self._instrumentor.instrument_app(app)
         return app
 
+    def _create_app_explicit_excluded_urls(self):
+        app = self._create_fastapi_app()
+        to_exclude = "/user/123,/foobar"
+        excluded_urls = [
+            excluded_url.strip() for excluded_url in to_exclude.split(",")
+        ]
+        self._instrumentor.instrument_app(
+            app, excluded_urls=ExcludeList(excluded_urls)
+        )
+        return app
+
     def setUp(self):
         super().setUp()
         self.env_patch = patch.dict(
@@ -84,6 +95,17 @@ def test_fastapi_excluded_urls(self):
         spans = self.memory_exporter.get_finished_spans()
         self.assertEqual(len(spans), 0)
 
+    def test_fastapi_excluded_urls_not_env(self):
+        """Ensure that given fastapi routes are excluded when passed explicitly (not in the environment)"""
+        app = self._create_app_explicit_excluded_urls()
+        client = TestClient(app)
+        client.get("/user/123")
+        spans = self.memory_exporter.get_finished_spans()
+        self.assertEqual(len(spans), 0)
+        client.get("/foobar")
+        spans = self.memory_exporter.get_finished_spans()
+        self.assertEqual(len(spans), 0)
+
     @staticmethod
     def _create_fastapi_app():
         app = fastapi.FastAPI()
@@ -124,6 +146,24 @@ def _create_app(self):
         self._instrumentor.instrument(tracer_provider=tracer_provider)
         return self._create_fastapi_app()
 
+    def _create_app_explicit_excluded_urls(self):
+        resource = Resource.create({"key1": "value1", "key2": "value2"})
+        tracer_provider, exporter = self.create_tracer_provider(
+            resource=resource
+        )
+        self.memory_exporter = exporter
+
+        to_exclude = "/user/123,/foobar"
+        excluded_urls = [
+            excluded_url.strip() for excluded_url in to_exclude.split(",")
+        ]
+        self._instrumentor.uninstrument()  # Disable previous instrumentation (setUp)
+        self._instrumentor.instrument(
+            tracer_provider=tracer_provider,
+            excluded_urls=ExcludeList(excluded_urls),
+        )
+        return self._create_fastapi_app()
+
     def test_request(self):
         self._client.get("/foobar")
         spans = self.memory_exporter.get_finished_spans()