Add http.target to Django duration metric attributes (#2624)

Author: alexmojaki

CHANGELOG.md

@@ -31,6 +31,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#2652](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2652))
 - `opentelemetry-instrumentation-aiohttp-client` Implement new semantic convention opt-in migration
   ([#2673](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2673))
+- `opentelemetry-instrumentation-django` Add `http.target` to Django duration metric attributes
+  ([#2624](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2624))
 
 ### Breaking changes
 

instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware/otel_middleware.py

@@ -315,6 +315,12 @@ def process_view(self, request, view_func, *args, **kwargs):
                     route = getattr(match, "route", None)
                     if route:
                         span.set_attribute(SpanAttributes.HTTP_ROUTE, route)
+                        duration_attrs = request.META[
+                            self._environ_duration_attr_key
+                        ]
+                        # Metrics currently use the 1.11.0 schema, which puts the route in `http.target`.
+                        # TODO: use `http.route` when the user sets `OTEL_SEMCONV_STABILITY_OPT_IN`.
+                        duration_attrs[SpanAttributes.HTTP_TARGET] = route
 
     def process_exception(self, request, exception):
         if self._excluded_urls.url_disabled(request.build_absolute_uri("?")):

instrumentation/opentelemetry-instrumentation-django/tests/test_middleware.py

@@ -480,7 +480,8 @@ def test_wsgi_metrics(self):
         ]
         _recommended_attrs = {
             "http.server.active_requests": _active_requests_count_attrs,
-            "http.server.duration": _duration_attrs,
+            "http.server.duration": _duration_attrs
+            | {SpanAttributes.HTTP_TARGET},
         }
         start = default_timer()
         for _ in range(3):