Django enrich_metric_attributes from Labeler if set

Author: tammy-baylis-swi

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

@@ -294,6 +294,44 @@ def response_hook(span, request, response):
 | ``SQLCOMMENTER_WITH_DB_DRIVER``     | Database driver name used by Django.                      | ``db_driver='django.db.backends.postgresql'``                             |
 +-------------------------------------+-----------------------------------------------------------+---------------------------------------------------------------------------+
 
+Custom Metrics Attributes using Labeler
+***************************************
+The Django instrumentation reads from a labeler utility that supports adding custom
+attributes to HTTP server metrics at emit time, including:
+
+- Active requests counter (``http.server.active_requests``)
+- Duration histogram (``http.server.duration``)
+- Request duration histogram (``http.server.request.duration``)
+
+The custom attributes are stored only within the context of an instrumented
+request or operation. The instrumentor does not overwrite base attributes that
+exist at the same keys as any custom attributes.
+
+
+.. code:: python
+
+    from django.http import HttpResponse
+    from opentelemetry.instrumentation._labeler import get_labeler
+    from opentelemetry.instrumentation.django import DjangoInstrumentor
+
+    DjangoInstrumentor().instrument()
+
+    # Note: urlpattern `/users/<user_id>/` mapped elsewhere
+    def my_user_view(request, user_id):
+        # Get the labeler for the current request
+        labeler = get_labeler()
+
+        # Add custom attributes to Django instrumentation metrics
+        labeler.add("user_id", user_id)
+        labeler.add("user_type", "registered")
+
+        # Or, add multiple attributes at once
+        labeler.add_attributes({
+            "feature_flag": "new_ui",
+            "experiment_group": "control"
+        })
+        return HttpResponse("Done!")
+
 API
 ---
 

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

@@ -22,6 +22,7 @@
 from django.http import HttpRequest, HttpResponse
 
 from opentelemetry.context import detach
+from opentelemetry.instrumentation._labeler import enrich_metric_attributes
 from opentelemetry.instrumentation._semconv import (
     _filter_semconv_active_request_count_attr,
     _filter_semconv_duration_attrs,
@@ -227,7 +228,9 @@ def process_request(self, request):
         )
         # Pass all of attributes to duration key because we will filter during response
         request.META[self._environ_duration_attr_key] = attributes
-        self._active_request_counter.add(1, active_requests_count_attrs)
+        self._active_request_counter.add(
+            1, enrich_metric_attributes(active_requests_count_attrs)
+        )
         if span.is_recording():
             attributes = extract_attributes_from_object(
                 request, self._traced_request_attrs, attributes
@@ -415,6 +418,9 @@ def process_response(self, request, response):
                 target = duration_attrs.get(HTTP_TARGET)
                 if target:
                     duration_attrs_old[HTTP_TARGET] = target
+                duration_attrs_old = enrich_metric_attributes(
+                    duration_attrs_old
+                )
                 self._duration_histogram_old.record(
                     max(round(duration_s * 1000), 0),
                     duration_attrs_old,
@@ -423,11 +429,16 @@ def process_response(self, request, response):
                 duration_attrs_new = _parse_duration_attrs(
                     duration_attrs, _StabilityMode.HTTP
                 )
+                duration_attrs_new = enrich_metric_attributes(
+                    duration_attrs_new
+                )
                 self._duration_histogram_new.record(
                     max(duration_s, 0),
                     duration_attrs_new,
                 )
-        self._active_request_counter.add(-1, active_requests_count_attrs)
+        self._active_request_counter.add(
+            -1, enrich_metric_attributes(active_requests_count_attrs)
+        )
 
         if activation and span:
             if exception:

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

@@ -25,6 +25,7 @@
 from django.test.utils import setup_test_environment, teardown_test_environment
 
 from opentelemetry import trace
+from opentelemetry.instrumentation._labeler import clear_labeler
 from opentelemetry.instrumentation._semconv import (
     HTTP_DURATION_HISTOGRAM_BUCKETS_NEW,
     HTTP_DURATION_HISTOGRAM_BUCKETS_OLD,
@@ -35,6 +36,9 @@
     DjangoInstrumentor,
     _DjangoMiddleware,
 )
+from opentelemetry.instrumentation.django.middleware import (
+    otel_middleware as django_otel_middleware,
+)
 from opentelemetry.instrumentation.propagators import (
     TraceResponsePropagator,
     set_global_response_propagator,
@@ -69,6 +73,7 @@
     excluded_noarg2,
     response_with_custom_header,
     route_span_name,
+    route_span_name_custom_attributes,
     traced,
     traced_template,
 )
@@ -95,6 +100,10 @@ def path(path_argument, *args, **kwargs):
     re_path(r"^excluded_noarg/", excluded_noarg),
     re_path(r"^excluded_noarg2/", excluded_noarg2),
     re_path(r"^span_name/([0-9]{4})/$", route_span_name),
+    re_path(
+        r"^span_name_custom_attrs/([0-9]{4})/$",
+        route_span_name_custom_attributes,
+    ),
     path("", traced, name="empty"),
 ]
 _django_instrumentor = DjangoInstrumentor()
@@ -117,6 +126,7 @@ def setUpClass(cls):
 
     def setUp(self):
         super().setUp()
+        clear_labeler()
         setup_test_environment()
         test_name = ""
         if hasattr(self, "_testMethodName"):
@@ -766,6 +776,111 @@ def test_wsgi_metrics(self):
                     )
         self.assertTrue(histrogram_data_point_seen and number_data_point_seen)
 
+    def test_wsgi_metrics_custom_attributes_skip_override(self):
+        expected_duration_attributes = {
+            "http.method": "GET",
+            "http.scheme": "http",
+            "http.flavor": "1.1",
+            "http.server_name": "testserver",
+            "net.host.port": 80,
+            "http.status_code": 200,
+            "http.target": "^span_name_custom_attrs/([0-9]{4})/$",
+            "custom_attr": "test_value",
+        }
+
+        response = Client().get("/span_name_custom_attrs/1234/")
+        self.assertEqual(response.status_code, 200)
+
+        metrics = self.get_sorted_metrics(SCOPE)
+        active_requests_point_seen = False
+        histogram_data_point_seen = False
+        for metric in metrics:
+            if metric.name == "http.server.active_requests":
+                data_points = list(metric.data.data_points)
+                for point in data_points:
+                    self.assertIsInstance(point, NumberDataPoint)
+                    if point.attributes.get("custom_attr") != "test_value":
+                        continue
+                    self.assertEqual(point.attributes["http.method"], "GET")
+                    active_requests_point_seen = True
+                continue
+
+            if metric.name != "http.server.duration":
+                continue
+            data_points = list(metric.data.data_points)
+            self.assertEqual(len(data_points), 1)
+            point = data_points[0]
+            self.assertIsInstance(point, HistogramDataPoint)
+            histogram_data_point_seen = True
+            self.assertDictEqual(
+                expected_duration_attributes, dict(point.attributes)
+            )
+
+        self.assertTrue(active_requests_point_seen)
+        self.assertTrue(histogram_data_point_seen)
+
+    def test_wsgi_active_requests_custom_attributes_new_semconv(self):
+        response = Client().get("/span_name_custom_attrs/1234/")
+        self.assertEqual(response.status_code, 200)
+
+        metrics = self.get_sorted_metrics(SCOPE)
+        active_requests_point_seen = False
+        for metric in metrics:
+            if metric.name != "http.server.active_requests":
+                continue
+            data_points = list(metric.data.data_points)
+            for point in data_points:
+                self.assertIsInstance(point, NumberDataPoint)
+                if point.attributes.get("custom_attr") != "test_value":
+                    continue
+                self.assertEqual(
+                    point.attributes["http.request.method"], "GET"
+                )
+                active_requests_point_seen = True
+
+        self.assertTrue(active_requests_point_seen)
+
+    def test_wsgi_active_requests_attrs_use_enrich_old_semconv(self):
+        with patch(
+            "opentelemetry.instrumentation.django.middleware.otel_middleware.enrich_metric_attributes",
+            wraps=django_otel_middleware.enrich_metric_attributes,
+        ) as mock_enrich:
+            response = Client().get("/span_name/1234/")
+            self.assertEqual(response.status_code, 200)
+
+        enriched_active_attrs_seen = False
+        for call in mock_enrich.call_args_list:
+            if not call.args:
+                continue
+            attrs = call.args[0]
+            if "http.method" in attrs and "http.status_code" not in attrs:
+                enriched_active_attrs_seen = True
+                break
+
+        self.assertTrue(enriched_active_attrs_seen)
+
+    def test_wsgi_active_requests_attrs_use_enrich_new_semconv(self):
+        with patch(
+            "opentelemetry.instrumentation.django.middleware.otel_middleware.enrich_metric_attributes",
+            wraps=django_otel_middleware.enrich_metric_attributes,
+        ) as mock_enrich:
+            response = Client().get("/span_name/1234/")
+            self.assertEqual(response.status_code, 200)
+
+        enriched_active_attrs_seen = False
+        for call in mock_enrich.call_args_list:
+            if not call.args:
+                continue
+            attrs = call.args[0]
+            if (
+                "http.request.method" in attrs
+                and "http.response.status_code" not in attrs
+            ):
+                enriched_active_attrs_seen = True
+                break
+
+        self.assertTrue(enriched_active_attrs_seen)
+
     # pylint: disable=too-many-locals
     def test_wsgi_metrics_new_semconv(self):
         _expected_metric_names = [

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

@@ -1,5 +1,7 @@
 from django.http import HttpResponse
 
+from opentelemetry.instrumentation._labeler import get_labeler
+
 
 def traced(request):  # pylint: disable=unused-argument
     return HttpResponse()
@@ -29,6 +31,13 @@ def route_span_name(request, *args, **kwargs):  # pylint: disable=unused-argumen
     return HttpResponse()
 
 
+def route_span_name_custom_attributes(request, *args, **kwargs):  # pylint: disable=unused-argument
+    labeler = get_labeler()
+    labeler.add("custom_attr", "test_value")
+    labeler.add("http.method", "POST")
+    return HttpResponse()
+
+
 def response_with_custom_header(request):
     response = HttpResponse()
     response["custom-test-header-1"] = "test-header-value-1"