starlette/fastapi: fix error on host-based routing

Fix #3506

Author: frankie567

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

@@ -428,8 +428,11 @@ def _get_route_details(scope):
     for starlette_route in app.routes:
         match, _ = starlette_route.matches(scope)
         if match == Match.FULL:
-            route = starlette_route.path
-            break
+            try:
+                route = starlette_route.path
+            except AttributeError:
+                # routes added via host routing won't have a path attribute
+                route = scope.get("path")
         if match == Match.PARTIAL:
             route = starlette_route.path
     return route

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

@@ -207,6 +207,7 @@ async def _():
             return {"message": "ok"}
 
         app.mount("/sub", app=sub_app)
+        app.host("testserver2", sub_app)
 
         return app
 
@@ -263,6 +264,10 @@ def test_sub_app_fastapi_call(self):
             span.attributes[SpanAttributes.HTTP_URL],
         )
 
+    def test_host_fastapi_call(self):
+        client = TestClient(self._app, base_url="https://testserver2")
+        client.get("/")
+
 
 class TestBaseAutoFastAPI(TestBaseFastAPI):
     @classmethod

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

@@ -355,7 +355,11 @@ def _get_route_details(scope: dict[str, Any]) -> str | None:
     for starlette_route in app.routes:
         match, _ = starlette_route.matches(scope)
         if match == Match.FULL:
-            route = starlette_route.path
+            try:
+                route = starlette_route.path
+            except AttributeError:
+                # routes added via host routing won't have a path attribute
+                route = scope.get("path")
             break
         if match == Match.PARTIAL:
             route = starlette_route.path

instrumentation/opentelemetry-instrumentation-starlette/tests/test_starlette_instrumentation.py

@@ -18,7 +18,7 @@
 
 from starlette import applications
 from starlette.responses import PlainTextResponse
-from starlette.routing import Mount, Route
+from starlette.routing import Host, Mount, Route
 from starlette.testclient import TestClient
 from starlette.websockets import WebSocket
 
@@ -140,6 +140,10 @@ def test_sub_app_starlette_call(self):
                 span.attributes[SpanAttributes.HTTP_URL],
             )
 
+    def test_host_starlette_call(self):
+        client = TestClient(self._app, base_url="http://testserver2")
+        client.get("/")
+
     def test_starlette_route_attribute_added(self):
         """Ensure that starlette routes are used as the span name."""
         self._client.get("/user/123")
@@ -298,6 +302,7 @@ def sub_home(_):
                 Route("/user/{username}", home),
                 Route("/healthzz", health),
                 Mount("/sub", app=sub_app),
+                Host("testserver2", sub_app),
             ],
         )