Adding metric collection as part of instrumentations - Django (#1230)

instrumentation/opentelemetry-instrumentation-django/CHANGELOG.md

@@ -11,6 +11,8 @@ Released 2020-10-13
 - Changed span name extraction from request to comply semantic convention ([#992](https://github.com/open-telemetry/opentelemetry-python/pull/992)) 
 - Added support for `OTEL_PYTHON_DJANGO_TRACED_REQUEST_ATTRS` ([#1154](https://github.com/open-telemetry/opentelemetry-python/pull/1154))
 - Added capture of http.route ([#1226](https://github.com/open-telemetry/opentelemetry-python/issues/1226))
+- Add support for tracking http metrics
+  ([#1230](https://github.com/open-telemetry/opentelemetry-python/pull/1230))
 
 ## Version 0.13b0
 

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

@@ -18,12 +18,18 @@ from django.conf import settings
 
 from opentelemetry.configuration import Configuration
 from opentelemetry.instrumentation.django.middleware import _DjangoMiddleware
+from opentelemetry.instrumentation.django.version import __version__
 from opentelemetry.instrumentation.instrumentor import BaseInstrumentor
+from opentelemetry.instrumentation.metric import (
+    HTTPMetricRecorder,
+    HTTPMetricType,
+    MetricMixin,
+)
 
 _logger = getLogger(__name__)
 
 
-class DjangoInstrumentor(BaseInstrumentor):
+class DjangoInstrumentor(BaseInstrumentor, MetricMixin):
     """An instrumentor for Django
 
     See `BaseInstrumentor`
@@ -57,6 +63,11 @@ class DjangoInstrumentor(BaseInstrumentor):
             settings_middleware = list(settings_middleware)
 
         settings_middleware.insert(0, self._opentelemetry_middleware)
+        self.init_metrics(
+            __name__, __version__,
+        )
+        metric_recorder = HTTPMetricRecorder(self.meter, HTTPMetricType.SERVER)
+        setattr(settings, "OTEL_METRIC_RECORDER", metric_recorder)
         setattr(settings, "MIDDLEWARE", settings_middleware)
 
     def _uninstrument(self, **kwargs):

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

@@ -12,8 +12,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import time
 from logging import getLogger
 
+from django.conf import settings
+
 from opentelemetry.configuration import Configuration
 from opentelemetry.context import attach, detach
 from opentelemetry.instrumentation.django.version import __version__
@@ -41,11 +44,16 @@ except ImportError:
     MiddlewareMixin = object
 
 _logger = getLogger(__name__)
+_attributes_by_preference = [
+    ["http.scheme", "http.host", "http.target"],
+    ["http.scheme", "http.server_name", "net.host.port", "http.target"],
+    ["http.scheme", "net.host.name", "net.host.port", "http.target"],
+    ["http.url"],
+]
 
 
 class _DjangoMiddleware(MiddlewareMixin):
-    """Django Middleware for OpenTelemetry
-    """
+    """Django Middleware for OpenTelemetry"""
 
     _environ_activation_key = (
         "opentelemetry-instrumentor-django.activation_key"
@@ -88,6 +96,21 @@ class _DjangoMiddleware(MiddlewareMixin):
         except Resolver404:
             return "HTTP {}".format(request.method)
 
+    @staticmethod
+    def _get_metric_labels_from_attributes(attributes):
+        labels = {}
+        labels["http.method"] = attributes.get("http.method", "")
+        for attrs in _attributes_by_preference:
+            labels_from_attributes = {
+                attr: attributes.get(attr, None) for attr in attrs
+            }
+            if set(attrs).issubset(attributes.keys()):
+                labels.update(labels_from_attributes)
+                break
+        if attributes.get("http.flavor"):
+            labels["http.flavor"] = attributes.get("http.flavor")
+        return labels
+
     def process_request(self, request):
         # request.META is a dictionary containing all available HTTP headers
         # Read more about request.META here:
@@ -96,6 +119,9 @@ class _DjangoMiddleware(MiddlewareMixin):
         if self._excluded_urls.url_disabled(request.build_absolute_uri("?")):
             return
 
+        # pylint:disable=W0212
+        request._otel_start_time = time.time()
+
         environ = request.META
 
         token = attach(extract(get_header_from_environ, environ))
@@ -110,8 +136,13 @@ class _DjangoMiddleware(MiddlewareMixin):
             ),
         )
 
+        attributes = collect_request_attributes(environ)
+        # pylint:disable=W0212
+        request._otel_labels = self._get_metric_labels_from_attributes(
+            attributes
+        )
+
         if span.is_recording():
-            attributes = collect_request_attributes(environ)
             attributes = extract_attributes_from_object(
                 request, self._traced_request_attrs, attributes
             )
@@ -176,6 +207,10 @@ class _DjangoMiddleware(MiddlewareMixin):
                 "{} {}".format(response.status_code, response.reason_phrase),
                 response,
             )
+            # pylint:disable=W0212
+            request._otel_labels["http.status_code"] = str(
+                response.status_code
+            )
             request.META.pop(self._environ_span_key)
 
             request.META[self._environ_activation_key].__exit__(
@@ -187,4 +222,14 @@ class _DjangoMiddleware(MiddlewareMixin):
             detach(request.environ.get(self._environ_token))
             request.META.pop(self._environ_token)
 
+        try:
+            metric_recorder = getattr(settings, "OTEL_METRIC_RECORDER", None)
+            if metric_recorder is not None:
+                # pylint:disable=W0212
+                metric_recorder.record_server_duration_range(
+                    request._otel_start_time, time.time(), request._otel_labels
+                )
+        except Exception as ex:  # pylint: disable=W0703
+            _logger.warning("Error recording duration metrics: %s", ex)
+
         return response

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

@@ -23,6 +23,8 @@ from django.test.utils import setup_test_environment, teardown_test_environment
 
 from opentelemetry.configuration import Configuration
 from opentelemetry.instrumentation.django import DjangoInstrumentor
+from opentelemetry.sdk.util import get_dict_as_key
+from opentelemetry.test.test_base import TestBase
 from opentelemetry.test.wsgitestutil import WsgiTestBase
 from opentelemetry.trace import SpanKind
 from opentelemetry.trace.status import StatusCanonicalCode
@@ -53,7 +55,7 @@ urlpatterns = [
 _django_instrumentor = DjangoInstrumentor()
 
 
-class TestMiddleware(WsgiTestBase):
+class TestMiddleware(TestBase, WsgiTestBase):
     @classmethod
     def setUpClass(cls):
         super().setUpClass()
@@ -121,6 +123,26 @@ class TestMiddleware(WsgiTestBase):
         self.assertEqual(span.attributes["http.status_code"], 200)
         self.assertEqual(span.attributes["http.status_text"], "OK")
 
+        self.assertIsNotNone(_django_instrumentor.meter)
+        self.assertEqual(len(_django_instrumentor.meter.metrics), 1)
+        recorder = _django_instrumentor.meter.metrics.pop()
+        match_key = get_dict_as_key(
+            {
+                "http.flavor": "1.1",
+                "http.method": "GET",
+                "http.status_code": "200",
+                "http.url": "http://testserver/traced/",
+            }
+        )
+        for key in recorder.bound_instruments.keys():
+            self.assertEqual(key, match_key)
+            # pylint: disable=protected-access
+            bound = recorder.bound_instruments.get(key)
+            for view_data in bound.view_datas:
+                self.assertEqual(view_data.labels, key)
+                self.assertEqual(view_data.aggregator.current.count, 1)
+                self.assertGreaterEqual(view_data.aggregator.current.sum, 0)
+
     def test_not_recording(self):
         mock_tracer = Mock()
         mock_span = Mock()
@@ -180,6 +202,23 @@ class TestMiddleware(WsgiTestBase):
         )
         self.assertEqual(span.attributes["http.route"], "^error/")
         self.assertEqual(span.attributes["http.scheme"], "http")
+        self.assertIsNotNone(_django_instrumentor.meter)
+        self.assertEqual(len(_django_instrumentor.meter.metrics), 1)
+        recorder = _django_instrumentor.meter.metrics.pop()
+        match_key = get_dict_as_key(
+            {
+                "http.flavor": "1.1",
+                "http.method": "GET",
+                "http.url": "http://testserver/error/",
+            }
+        )
+        for key in recorder.bound_instruments.keys():
+            self.assertEqual(key, match_key)
+            # pylint: disable=protected-access
+            bound = recorder.bound_instruments.get(key)
+            for view_data in bound.view_datas:
+                self.assertEqual(view_data.labels, key)
+                self.assertEqual(view_data.aggregator.current.count, 1)
 
     @patch(
         "opentelemetry.instrumentation.django.middleware._DjangoMiddleware._excluded_urls",