From 89b4e6be483a57c72865e52676c0e2ee6c3dcd13 Mon Sep 17 00:00:00 2001
From: Leighton <lechen@microsoft.com>
Date: Mon, 12 Oct 2020 14:45:10 -0400
Subject: [PATCH 01/12] django

---
 docs/examples/django/manage.py                |  6 +-
 .../instrumentation/django/__init__.py        | 21 +++---
 .../instrumentation/django/middleware.py      | 41 +++++++++++-
 .../instrumentation/requests/__init__.py      |  6 +-
 .../opentelemetry/instrumentation/metric.py   | 66 ++++++++++++++-----
 5 files changed, 104 insertions(+), 36 deletions(-)

diff --git a/docs/examples/django/manage.py b/docs/examples/django/manage.py
index 3a67dbf8296..bc2d44886b4 100755
--- a/docs/examples/django/manage.py
+++ b/docs/examples/django/manage.py
@@ -21,13 +21,13 @@
 
 
 def main():
+    os.environ.setdefault(
+        "DJANGO_SETTINGS_MODULE", "instrumentation_example.settings"
+    )
 
     # This call is what makes the Django application be instrumented
     DjangoInstrumentor().instrument()
 
-    os.environ.setdefault(
-        "DJANGO_SETTINGS_MODULE", "instrumentation_example.settings"
-    )
     try:
         from django.core.management import execute_from_command_line
     except ImportError as exc:
diff --git a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/__init__.py b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/__init__.py
index a9bd620e77c..5b2544512e0 100644
--- a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/__init__.py
+++ b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/__init__.py
@@ -18,12 +18,18 @@
 
 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`
@@ -34,16 +40,6 @@ class DjangoInstrumentor(BaseInstrumentor):
     )
 
     def _instrument(self, **kwargs):
-
-        # FIXME this is probably a pattern that will show up in the rest of the
-        # ext. Find a better way of implementing this.
-        # FIXME Probably the evaluation of strings into boolean values can be
-        # built inside the Configuration class itself with the magic method
-        # __bool__
-
-        if not Configuration().DJANGO_INSTRUMENT:
-            return
-
         # This can not be solved, but is an inherent problem of this approach:
         # the order of middleware entries matters, and here you have no control
         # on that:
@@ -57,6 +53,9 @@ def _instrument(self, **kwargs):
             settings_middleware = list(settings_middleware)
 
         settings_middleware.insert(0, self._opentelemetry_middleware)
+        self.init_metrics(__name__, __version__,)
+        metric_recorder = HTTPMetricRecorder(self.meter, HTTPMetricType.BOTH)
+        setattr(settings, "OTEL_METRIC_RECORDER", metric_recorder)
         setattr(settings, "MIDDLEWARE", settings_middleware)
 
     def _uninstrument(self, **kwargs):
diff --git a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
index 11991413eb8..6201b506e81 100644
--- a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
+++ b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
@@ -12,8 +12,12 @@
 # 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__
@@ -88,6 +92,28 @@ def _get_span_name(request):
         except Resolver404:
             return "HTTP {}".format(request.method)
 
+    @staticmethod
+    def _get_metric_labels_from_attributes(attributes):
+        labels = {}
+        labels["http.method"] = attributes.get("http.method", "")
+        if attributes.get("http.url"):
+            labels["http.url"] = attributes.get("http.url")
+        elif attributes.get("http.scheme"):
+            labels["http.scheme"] = attributes.get("http.scheme")
+            if attributes.get("http.target"):
+                labels["http.target"] = attributes.get("http.target")
+                if attributes.get("http.host"):
+                    labels["http.host"] = attributes.get("http.host")
+                elif attributes.get("net.host.port"):
+                    labels["net.host.port"] = attributes.get("net.host.port")
+                    if attributes.get("http.server_name"):
+                        labels["http.server_name"] = attributes.get("http.server_name")
+                    elif attributes.get("http.host.name"):
+                        labels["http.host.name"] = attributes.get("http.host.name")
+        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 +122,8 @@ def process_request(self, request):
         if self._excluded_urls.url_disabled(request.build_absolute_uri("?")):
             return
 
+        request.start_time = time.time()
+
         environ = request.META
 
         token = attach(extract(get_header_from_environ, environ))
@@ -110,8 +138,10 @@ def process_request(self, request):
             ),
         )
 
+        attributes = collect_request_attributes(environ)
+        request.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
             )
@@ -156,6 +186,7 @@ def process_response(self, request, response):
                 "{} {}".format(response.status_code, response.reason_phrase),
                 response,
             )
+            request.labels["http.status_code"] = str(response.status_code)
             request.META.pop(self._environ_span_key)
 
             request.META[self._environ_activation_key].__exit__(
@@ -167,4 +198,12 @@ def process_response(self, request, response):
             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:
+                metric_recorder.record_server_duration_range(
+                    request.start_time, time.time(), request.labels)
+        except Exception as ex:  # pylint: disable=W0703
+            _logger.warning("Error recording duration metrics: {}", ex)
+
         return response
diff --git a/instrumentation/opentelemetry-instrumentation-requests/src/opentelemetry/instrumentation/requests/__init__.py b/instrumentation/opentelemetry-instrumentation-requests/src/opentelemetry/instrumentation/requests/__init__.py
index 4b5f73de9e6..cf9463f4caa 100644
--- a/instrumentation/opentelemetry-instrumentation-requests/src/opentelemetry/instrumentation/requests/__init__.py
+++ b/instrumentation/opentelemetry-instrumentation-requests/src/opentelemetry/instrumentation/requests/__init__.py
@@ -45,6 +45,7 @@
 from opentelemetry.instrumentation.instrumentor import BaseInstrumentor
 from opentelemetry.instrumentation.metric import (
     HTTPMetricRecorder,
+    HTTPMetricType
     MetricMixin,
 )
 from opentelemetry.instrumentation.requests.version import __version__
@@ -135,7 +136,7 @@ def _instrumented_requests_call(
             __name__, __version__, tracer_provider
         ).start_as_current_span(span_name, kind=SpanKind.CLIENT) as span:
             exception = None
-            with recorder.record_duration(labels):
+            with recorder.record_client_duration(labels):
                 if span.is_recording():
                     span.set_attribute("component", "http")
                     span.set_attribute("http.method", method)
@@ -176,7 +177,6 @@ def _instrumented_requests_call(
                             )
                         )
                     labels["http.status_code"] = str(result.status_code)
-                    labels["http.status_text"] = result.reason
                     if result.raw and result.raw.version:
                         labels["http.flavor"] = (
                             str(result.raw.version)[:1]
@@ -253,7 +253,7 @@ def _instrument(self, **kwargs):
             __name__, __version__,
         )
         # pylint: disable=W0201
-        self.metric_recorder = HTTPMetricRecorder(self.meter, SpanKind.CLIENT)
+        self.metric_recorder = HTTPMetricRecorder(self.meter, HTTPMetricType.CLIENT)
 
     def _uninstrument(self, **kwargs):
         _uninstrument()
diff --git a/opentelemetry-instrumentation/src/opentelemetry/instrumentation/metric.py b/opentelemetry-instrumentation/src/opentelemetry/instrumentation/metric.py
index 74445cbff1b..cb582211d6c 100644
--- a/opentelemetry-instrumentation/src/opentelemetry/instrumentation/metric.py
+++ b/opentelemetry-instrumentation/src/opentelemetry/instrumentation/metric.py
@@ -28,7 +28,7 @@
 class HTTPMetricType(enum.Enum):
     CLIENT = 0
     SERVER = 1
-    # TODO: Add both
+    BOTH = 2
 
 
 class MetricMixin:
@@ -57,29 +57,59 @@ def __init__(
     ):
         super().__init__(meter)
         self._http_type = http_type
+        self._client_duration = None
+        self._server_duration = None
         if self._meter:
-            self._duration = self._meter.create_metric(
-                name="{}.{}.duration".format(
-                    "http", self._http_type.name.lower()
-                ),
-                description="measures the duration of the {} HTTP request".format(
-                    "inbound"
-                    if self._http_type is HTTPMetricType.SERVER
-                    else "outbound"
-                ),
-                unit="ms",
-                value_type=float,
-                metric_type=ValueRecorder,
-            )
+            if http_type in (HTTPMetricType.CLIENT, HTTPMetricType.BOTH):
+                self._client_duration = self._meter.create_metric(
+                    name="{}.{}.duration".format(
+                        "http", "client"
+                    ),
+                    description="measures the duration of the outbound HTTP request",
+                    unit="ms",
+                    value_type=float,
+                    metric_type=ValueRecorder,
+                )
+            if http_type is not HTTPMetricType.CLIENT:
+                self._server_duration = self._meter.create_metric(
+                    name="{}.{}.duration".format(
+                        "http", "server"
+                    ),
+                    description="measures the duration of the inbound HTTP request",
+                    unit="ms",
+                    value_type=float,
+                    metric_type=ValueRecorder,
+                )
 
     # Conventions for recording duration can be found at:
     # https://github.com/open-telemetry/opentelemetry-specification/blob/master/specification/metrics/semantic_conventions/http-metrics.md
     @contextmanager
-    def record_duration(self, labels: Dict[str, str]):
+    def record_client_duration(self, labels: Dict[str, str]):
+        if self._client_duration:
+            start_time = time()
+            try:
+                yield start_time
+            finally:
+                if self._meter:
+                    elapsed_time = (time() - start_time) * 1000
+                    self._client_duration.record(elapsed_time, labels)
+
+
+    @contextmanager
+    def record_server_duration(self, labels: Dict[str, str]):
         start_time = time()
         try:
             yield start_time
         finally:
-            if self._meter:
-                elapsed_time = (time() - start_time) * 1000
-                self._duration.record(elapsed_time, labels)
+            self.record_server_duration_range(start_time, time(), labels)
+
+
+    def record_server_duration_range(
+        self, 
+        start_time,
+        end_time,
+        labels: Dict[str, str]
+    ):
+        if self._server_duration:
+            elapsed_time = (end_time - start_time) * 1000
+            self._server_duration.record(elapsed_time, labels)

From e86964143114a0eba9ecfa060cea22bf14db91ef Mon Sep 17 00:00:00 2001
From: Leighton <lechen@microsoft.com>
Date: Mon, 12 Oct 2020 15:35:30 -0400
Subject: [PATCH 02/12] tests

---
 .../instrumentation/django/__init__.py        |  2 +-
 .../tests/test_middleware.py                  | 39 +++++++++++++++
 .../instrumentation/requests/__init__.py      |  2 +-
 .../tests/test_requests_integration.py        |  4 +-
 .../opentelemetry/instrumentation/metric.py   | 23 +++++----
 .../tests/test_metric.py                      | 49 ++++++++++++++++---
 .../src/opentelemetry/test/wsgitestutil.py    |  5 +-
 7 files changed, 100 insertions(+), 24 deletions(-)

diff --git a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/__init__.py b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/__init__.py
index 5b2544512e0..640eaf50f3e 100644
--- a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/__init__.py
+++ b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/__init__.py
@@ -54,7 +54,7 @@ def _instrument(self, **kwargs):
 
         settings_middleware.insert(0, self._opentelemetry_middleware)
         self.init_metrics(__name__, __version__,)
-        metric_recorder = HTTPMetricRecorder(self.meter, HTTPMetricType.BOTH)
+        metric_recorder = HTTPMetricRecorder(self.meter, HTTPMetricType.SERVER)
         setattr(settings, "OTEL_METRIC_RECORDER", metric_recorder)
         setattr(settings, "MIDDLEWARE", settings_middleware)
 
diff --git a/instrumentation/opentelemetry-instrumentation-django/tests/test_middleware.py b/instrumentation/opentelemetry-instrumentation-django/tests/test_middleware.py
index 4db6c485dec..70c56ef30e7 100644
--- a/instrumentation/opentelemetry-instrumentation-django/tests/test_middleware.py
+++ b/instrumentation/opentelemetry-instrumentation-django/tests/test_middleware.py
@@ -23,6 +23,7 @@
 
 from opentelemetry.configuration import Configuration
 from opentelemetry.instrumentation.django import DjangoInstrumentor
+from opentelemetry.sdk.util import get_dict_as_key
 from opentelemetry.test.wsgitestutil import WsgiTestBase
 from opentelemetry.trace import SpanKind
 from opentelemetry.trace.status import StatusCanonicalCode
@@ -89,6 +90,26 @@ def test_traced_get(self):
         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()
@@ -146,6 +167,24 @@ def test_error(self):
             span.attributes["http.url"], "http://testserver/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",
diff --git a/instrumentation/opentelemetry-instrumentation-requests/src/opentelemetry/instrumentation/requests/__init__.py b/instrumentation/opentelemetry-instrumentation-requests/src/opentelemetry/instrumentation/requests/__init__.py
index cf9463f4caa..c2995ab38e2 100644
--- a/instrumentation/opentelemetry-instrumentation-requests/src/opentelemetry/instrumentation/requests/__init__.py
+++ b/instrumentation/opentelemetry-instrumentation-requests/src/opentelemetry/instrumentation/requests/__init__.py
@@ -45,7 +45,7 @@
 from opentelemetry.instrumentation.instrumentor import BaseInstrumentor
 from opentelemetry.instrumentation.metric import (
     HTTPMetricRecorder,
-    HTTPMetricType
+    HTTPMetricType,
     MetricMixin,
 )
 from opentelemetry.instrumentation.requests.version import __version__
diff --git a/instrumentation/opentelemetry-instrumentation-requests/tests/test_requests_integration.py b/instrumentation/opentelemetry-instrumentation-requests/tests/test_requests_integration.py
index 678499e8794..f41e597b23e 100644
--- a/instrumentation/opentelemetry-instrumentation-requests/tests/test_requests_integration.py
+++ b/instrumentation/opentelemetry-instrumentation-requests/tests/test_requests_integration.py
@@ -97,7 +97,6 @@ def test_basic(self):
                 "http.flavor": "1.1",
                 "http.method": "GET",
                 "http.status_code": "200",
-                "http.status_text": "OK",
                 "http.url": "http://httpbin.org/status/200",
             }
         )
@@ -108,7 +107,7 @@ def test_basic(self):
             for view_data in bound.view_datas:
                 self.assertEqual(view_data.labels, key)
                 self.assertEqual(view_data.aggregator.current.count, 1)
-                self.assertGreater(view_data.aggregator.current.sum, 0)
+                self.assertGreaterEqual(view_data.aggregator.current.sum, 0)
 
     def test_not_foundbasic(self):
         url_404 = "http://httpbin.org/status/404"
@@ -318,7 +317,6 @@ def test_requests_exception_with_response(self, *_, **__):
             {
                 "http.method": "GET",
                 "http.status_code": "500",
-                "http.status_text": "Internal Server Error",
                 "http.url": "http://httpbin.org/status/200",
             }
         )
diff --git a/opentelemetry-instrumentation/src/opentelemetry/instrumentation/metric.py b/opentelemetry-instrumentation/src/opentelemetry/instrumentation/metric.py
index cb582211d6c..25b24abf9a8 100644
--- a/opentelemetry-instrumentation/src/opentelemetry/instrumentation/metric.py
+++ b/opentelemetry-instrumentation/src/opentelemetry/instrumentation/metric.py
@@ -85,15 +85,21 @@ def __init__(
     # https://github.com/open-telemetry/opentelemetry-specification/blob/master/specification/metrics/semantic_conventions/http-metrics.md
     @contextmanager
     def record_client_duration(self, labels: Dict[str, str]):
-        if self._client_duration:
-            start_time = time()
-            try:
-                yield start_time
-            finally:
-                if self._meter:
-                    elapsed_time = (time() - start_time) * 1000
-                    self._client_duration.record(elapsed_time, labels)
+        start_time = time()
+        try:
+            yield start_time
+        finally:
+            self.record_client_duration_range(start_time, time(), labels)
 
+    def record_client_duration_range(
+        self, 
+        start_time,
+        end_time,
+        labels: Dict[str, str]
+    ):
+        if self._client_duration:
+            elapsed_time = (end_time - start_time) * 1000
+            self._client_duration.record(elapsed_time, labels)
 
     @contextmanager
     def record_server_duration(self, labels: Dict[str, str]):
@@ -103,7 +109,6 @@ def record_server_duration(self, labels: Dict[str, str]):
         finally:
             self.record_server_duration_range(start_time, time(), labels)
 
-
     def record_server_duration_range(
         self, 
         start_time,
diff --git a/opentelemetry-instrumentation/tests/test_metric.py b/opentelemetry-instrumentation/tests/test_metric.py
index ea8724fc889..5d11dbb9b4e 100644
--- a/opentelemetry-instrumentation/tests/test_metric.py
+++ b/opentelemetry-instrumentation/tests/test_metric.py
@@ -61,26 +61,61 @@ def test_ctor(self):
         recorder = HTTPMetricRecorder(meter, HTTPMetricType.CLIENT)
         # pylint: disable=protected-access
         self.assertEqual(recorder._http_type, HTTPMetricType.CLIENT)
-        self.assertTrue(isinstance(recorder._duration, metrics.ValueRecorder))
-        self.assertEqual(recorder._duration.name, "http.client.duration")
+        self.assertTrue(isinstance(recorder._client_duration, metrics.ValueRecorder))
+        self.assertEqual(recorder._client_duration.name, "http.client.duration")
         self.assertEqual(
-            recorder._duration.description,
+            recorder._client_duration.description,
             "measures the duration of the outbound HTTP request",
         )
 
-    def test_record_duration(self):
+    def test_ctor_types(self):
         meter = metrics_api.get_meter(__name__)
         recorder = HTTPMetricRecorder(meter, HTTPMetricType.CLIENT)
+        self.assertEqual(recorder._http_type, HTTPMetricType.CLIENT)
+        self.assertTrue(isinstance(recorder._client_duration, metrics.ValueRecorder))
+        self.assertIsNone(recorder._server_duration)
+
+        recorder = HTTPMetricRecorder(meter, HTTPMetricType.SERVER)
+        self.assertEqual(recorder._http_type, HTTPMetricType.SERVER)
+        self.assertTrue(isinstance(recorder._server_duration, metrics.ValueRecorder))
+        self.assertIsNone(recorder._client_duration)
+
+        recorder = HTTPMetricRecorder(meter, HTTPMetricType.BOTH)
+        self.assertEqual(recorder._http_type, HTTPMetricType.BOTH)
+        self.assertTrue(isinstance(recorder._client_duration, metrics.ValueRecorder))
+        self.assertTrue(isinstance(recorder._server_duration, metrics.ValueRecorder))
+
+    def test_record_client_duration(self):
+        meter = metrics_api.get_meter(__name__)
+        recorder = HTTPMetricRecorder(meter, HTTPMetricType.CLIENT)
+        labels = {"test": "asd"}
+        with mock.patch("time.time") as time_patch:
+            time_patch.return_value = 5.0
+            with recorder.record_client_duration(labels):
+                labels["test2"] = "asd2"
+        match_key = get_dict_as_key({"test": "asd", "test2": "asd2"})
+        for key in recorder._client_duration.bound_instruments.keys():
+            self.assertEqual(key, match_key)
+            # pylint: disable=protected-access
+            bound = recorder._client_duration.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_record_server_duration(self):
+        meter = metrics_api.get_meter(__name__)
+        recorder = HTTPMetricRecorder(meter, HTTPMetricType.SERVER)
         labels = {"test": "asd"}
         with mock.patch("time.time") as time_patch:
             time_patch.return_value = 5.0
-            with recorder.record_duration(labels):
+            with recorder.record_server_duration(labels):
                 labels["test2"] = "asd2"
         match_key = get_dict_as_key({"test": "asd", "test2": "asd2"})
-        for key in recorder._duration.bound_instruments.keys():
+        for key in recorder._server_duration.bound_instruments.keys():
             self.assertEqual(key, match_key)
             # pylint: disable=protected-access
-            bound = recorder._duration.bound_instruments.get(key)
+            bound = recorder._server_duration.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)
diff --git a/tests/util/src/opentelemetry/test/wsgitestutil.py b/tests/util/src/opentelemetry/test/wsgitestutil.py
index 349db8f6944..1396760cf89 100644
--- a/tests/util/src/opentelemetry/test/wsgitestutil.py
+++ b/tests/util/src/opentelemetry/test/wsgitestutil.py
@@ -15,10 +15,9 @@
 import io
 import wsgiref.util as wsgiref_util
 
-from opentelemetry.test.spantestutil import SpanTestBase
+from opentelemetry.test.test_base import TestBase
 
-
-class WsgiTestBase(SpanTestBase):
+class WsgiTestBase(TestBase):
     def setUp(self):
         super().setUp()
 

From 585ca48586f3182929b06cf6e00837dbef3a1dea Mon Sep 17 00:00:00 2001
From: Leighton <lechen@microsoft.com>
Date: Mon, 12 Oct 2020 15:36:33 -0400
Subject: [PATCH 03/12] changelog

---
 .../opentelemetry-instrumentation-django/CHANGELOG.md           | 2 ++
 .../opentelemetry-instrumentation-requests/CHANGELOG.md         | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/instrumentation/opentelemetry-instrumentation-django/CHANGELOG.md b/instrumentation/opentelemetry-instrumentation-django/CHANGELOG.md
index 30b13c4a223..ae2f50880ff 100644
--- a/instrumentation/opentelemetry-instrumentation-django/CHANGELOG.md
+++ b/instrumentation/opentelemetry-instrumentation-django/CHANGELOG.md
@@ -4,6 +4,8 @@
 
 - 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))
+- Add support for tracking http metrics
+  ([#1116](https://github.com/open-telemetry/opentelemetry-python/pull/1116))
 
 ## Version 0.13b0
 
diff --git a/instrumentation/opentelemetry-instrumentation-requests/CHANGELOG.md b/instrumentation/opentelemetry-instrumentation-requests/CHANGELOG.md
index c2e4dcdbb92..96089a9da15 100644
--- a/instrumentation/opentelemetry-instrumentation-requests/CHANGELOG.md
+++ b/instrumentation/opentelemetry-instrumentation-requests/CHANGELOG.md
@@ -10,7 +10,7 @@ Released 2020-09-17
   ([#1040](https://github.com/open-telemetry/opentelemetry-python/pull/1040))
 - Drop support for Python 3.4
   ([#1099](https://github.com/open-telemetry/opentelemetry-python/pull/1099))
-- Add support for http metrics
+- Add support for tracking http metrics
   ([#1116](https://github.com/open-telemetry/opentelemetry-python/pull/1116))
 
 ## Version 0.12b0

From ad5bf9a68015e195f370f60199ca363ec003f31c Mon Sep 17 00:00:00 2001
From: Leighton <lechen@microsoft.com>
Date: Mon, 12 Oct 2020 15:59:58 -0400
Subject: [PATCH 04/12] tests

---
 .../CHANGELOG.md                              |  2 +-
 .../instrumentation/django/__init__.py        |  5 ++++-
 .../instrumentation/django/middleware.py      | 14 +++++++-----
 .../tests/test_middleware.py                  |  3 ++-
 .../instrumentation/requests/__init__.py      |  4 +++-
 .../opentelemetry/instrumentation/metric.py   | 22 ++++++-------------
 .../src/opentelemetry/test/wsgitestutil.py    |  5 +++--
 7 files changed, 29 insertions(+), 26 deletions(-)

diff --git a/instrumentation/opentelemetry-instrumentation-django/CHANGELOG.md b/instrumentation/opentelemetry-instrumentation-django/CHANGELOG.md
index ae2f50880ff..4def10a424e 100644
--- a/instrumentation/opentelemetry-instrumentation-django/CHANGELOG.md
+++ b/instrumentation/opentelemetry-instrumentation-django/CHANGELOG.md
@@ -5,7 +5,7 @@
 - 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))
 - Add support for tracking http metrics
-  ([#1116](https://github.com/open-telemetry/opentelemetry-python/pull/1116))
+  ([#1230](https://github.com/open-telemetry/opentelemetry-python/pull/1230))
 
 ## Version 0.13b0
 
diff --git a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/__init__.py b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/__init__.py
index 640eaf50f3e..32e2aadf8ec 100644
--- a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/__init__.py
+++ b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/__init__.py
@@ -53,7 +53,10 @@ def _instrument(self, **kwargs):
             settings_middleware = list(settings_middleware)
 
         settings_middleware.insert(0, self._opentelemetry_middleware)
-        self.init_metrics(__name__, __version__,)
+        self.init_metrics(
+            __name__,
+            __version__,
+        )
         metric_recorder = HTTPMetricRecorder(self.meter, HTTPMetricType.SERVER)
         setattr(settings, "OTEL_METRIC_RECORDER", metric_recorder)
         setattr(settings, "MIDDLEWARE", settings_middleware)
diff --git a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
index 6201b506e81..bc6e28cbe27 100644
--- a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
+++ b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
@@ -48,8 +48,7 @@
 
 
 class _DjangoMiddleware(MiddlewareMixin):
-    """Django Middleware for OpenTelemetry
-    """
+    """Django Middleware for OpenTelemetry"""
 
     _environ_activation_key = (
         "opentelemetry-instrumentor-django.activation_key"
@@ -107,9 +106,13 @@ def _get_metric_labels_from_attributes(attributes):
                 elif attributes.get("net.host.port"):
                     labels["net.host.port"] = attributes.get("net.host.port")
                     if attributes.get("http.server_name"):
-                        labels["http.server_name"] = attributes.get("http.server_name")
+                        labels["http.server_name"] = attributes.get(
+                            "http.server_name"
+                        )
                     elif attributes.get("http.host.name"):
-                        labels["http.host.name"] = attributes.get("http.host.name")
+                        labels["http.host.name"] = attributes.get(
+                            "http.host.name"
+                        )
         if attributes.get("http.flavor"):
             labels["http.flavor"] = attributes.get("http.flavor")
         return labels
@@ -202,7 +205,8 @@ def process_response(self, request, response):
             metric_recorder = getattr(settings, "OTEL_METRIC_RECORDER", None)
             if metric_recorder:
                 metric_recorder.record_server_duration_range(
-                    request.start_time, time.time(), request.labels)
+                    request.start_time, time.time(), request.labels
+                )
         except Exception as ex:  # pylint: disable=W0703
             _logger.warning("Error recording duration metrics: {}", ex)
 
diff --git a/instrumentation/opentelemetry-instrumentation-django/tests/test_middleware.py b/instrumentation/opentelemetry-instrumentation-django/tests/test_middleware.py
index 70c56ef30e7..a4289fc1215 100644
--- a/instrumentation/opentelemetry-instrumentation-django/tests/test_middleware.py
+++ b/instrumentation/opentelemetry-instrumentation-django/tests/test_middleware.py
@@ -24,6 +24,7 @@
 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
@@ -52,7 +53,7 @@
 _django_instrumentor = DjangoInstrumentor()
 
 
-class TestMiddleware(WsgiTestBase):
+class TestMiddleware(TestBase, WsgiTestBase):
     @classmethod
     def setUpClass(cls):
         super().setUpClass()
diff --git a/instrumentation/opentelemetry-instrumentation-requests/src/opentelemetry/instrumentation/requests/__init__.py b/instrumentation/opentelemetry-instrumentation-requests/src/opentelemetry/instrumentation/requests/__init__.py
index c2995ab38e2..770eacf5e27 100644
--- a/instrumentation/opentelemetry-instrumentation-requests/src/opentelemetry/instrumentation/requests/__init__.py
+++ b/instrumentation/opentelemetry-instrumentation-requests/src/opentelemetry/instrumentation/requests/__init__.py
@@ -253,7 +253,9 @@ def _instrument(self, **kwargs):
             __name__, __version__,
         )
         # pylint: disable=W0201
-        self.metric_recorder = HTTPMetricRecorder(self.meter, HTTPMetricType.CLIENT)
+        self.metric_recorder = HTTPMetricRecorder(
+            self.meter, HTTPMetricType.CLIENT
+        )
 
     def _uninstrument(self, **kwargs):
         _uninstrument()
diff --git a/opentelemetry-instrumentation/src/opentelemetry/instrumentation/metric.py b/opentelemetry-instrumentation/src/opentelemetry/instrumentation/metric.py
index 25b24abf9a8..a45ada3d9f0 100644
--- a/opentelemetry-instrumentation/src/opentelemetry/instrumentation/metric.py
+++ b/opentelemetry-instrumentation/src/opentelemetry/instrumentation/metric.py
@@ -53,7 +53,9 @@ class HTTPMetricRecorder(MetricRecorder):
     """Metric recorder for http instrumentations. Tracks duration."""
 
     def __init__(
-        self, meter: Optional[metrics.Meter], http_type: HTTPMetricType,
+        self,
+        meter: Optional[metrics.Meter],
+        http_type: HTTPMetricType,
     ):
         super().__init__(meter)
         self._http_type = http_type
@@ -62,9 +64,7 @@ def __init__(
         if self._meter:
             if http_type in (HTTPMetricType.CLIENT, HTTPMetricType.BOTH):
                 self._client_duration = self._meter.create_metric(
-                    name="{}.{}.duration".format(
-                        "http", "client"
-                    ),
+                    name="{}.{}.duration".format("http", "client"),
                     description="measures the duration of the outbound HTTP request",
                     unit="ms",
                     value_type=float,
@@ -72,9 +72,7 @@ def __init__(
                 )
             if http_type is not HTTPMetricType.CLIENT:
                 self._server_duration = self._meter.create_metric(
-                    name="{}.{}.duration".format(
-                        "http", "server"
-                    ),
+                    name="{}.{}.duration".format("http", "server"),
                     description="measures the duration of the inbound HTTP request",
                     unit="ms",
                     value_type=float,
@@ -92,10 +90,7 @@ def record_client_duration(self, labels: Dict[str, str]):
             self.record_client_duration_range(start_time, time(), labels)
 
     def record_client_duration_range(
-        self, 
-        start_time,
-        end_time,
-        labels: Dict[str, str]
+        self, start_time, end_time, labels: Dict[str, str]
     ):
         if self._client_duration:
             elapsed_time = (end_time - start_time) * 1000
@@ -110,10 +105,7 @@ def record_server_duration(self, labels: Dict[str, str]):
             self.record_server_duration_range(start_time, time(), labels)
 
     def record_server_duration_range(
-        self, 
-        start_time,
-        end_time,
-        labels: Dict[str, str]
+        self, start_time, end_time, labels: Dict[str, str]
     ):
         if self._server_duration:
             elapsed_time = (end_time - start_time) * 1000
diff --git a/tests/util/src/opentelemetry/test/wsgitestutil.py b/tests/util/src/opentelemetry/test/wsgitestutil.py
index 1396760cf89..349db8f6944 100644
--- a/tests/util/src/opentelemetry/test/wsgitestutil.py
+++ b/tests/util/src/opentelemetry/test/wsgitestutil.py
@@ -15,9 +15,10 @@
 import io
 import wsgiref.util as wsgiref_util
 
-from opentelemetry.test.test_base import TestBase
+from opentelemetry.test.spantestutil import SpanTestBase
 
-class WsgiTestBase(TestBase):
+
+class WsgiTestBase(SpanTestBase):
     def setUp(self):
         super().setUp()
 

From 1e71ed51e966a738291a50468db438b50128161f Mon Sep 17 00:00:00 2001
From: Leighton <lechen@microsoft.com>
Date: Mon, 12 Oct 2020 16:08:44 -0400
Subject: [PATCH 05/12] lint

---
 .../instrumentation/django/__init__.py        |  3 +--
 .../tests/test_middleware.py                  |  1 -
 .../opentelemetry/instrumentation/metric.py   |  4 +---
 .../tests/test_metric.py                      | 24 ++++++++++++++-----
 4 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/__init__.py b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/__init__.py
index 32e2aadf8ec..0d58c83c738 100644
--- a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/__init__.py
+++ b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/__init__.py
@@ -54,8 +54,7 @@ def _instrument(self, **kwargs):
 
         settings_middleware.insert(0, self._opentelemetry_middleware)
         self.init_metrics(
-            __name__,
-            __version__,
+            __name__, __version__,
         )
         metric_recorder = HTTPMetricRecorder(self.meter, HTTPMetricType.SERVER)
         setattr(settings, "OTEL_METRIC_RECORDER", metric_recorder)
diff --git a/instrumentation/opentelemetry-instrumentation-django/tests/test_middleware.py b/instrumentation/opentelemetry-instrumentation-django/tests/test_middleware.py
index a4289fc1215..5621babc888 100644
--- a/instrumentation/opentelemetry-instrumentation-django/tests/test_middleware.py
+++ b/instrumentation/opentelemetry-instrumentation-django/tests/test_middleware.py
@@ -186,7 +186,6 @@ def test_error(self):
                 self.assertEqual(view_data.labels, key)
                 self.assertEqual(view_data.aggregator.current.count, 1)
 
-
     @patch(
         "opentelemetry.instrumentation.django.middleware._DjangoMiddleware._excluded_urls",
         ExcludeList(["http://testserver/excluded_arg/123", "excluded_noarg"]),
diff --git a/opentelemetry-instrumentation/src/opentelemetry/instrumentation/metric.py b/opentelemetry-instrumentation/src/opentelemetry/instrumentation/metric.py
index a45ada3d9f0..3a58c6d031d 100644
--- a/opentelemetry-instrumentation/src/opentelemetry/instrumentation/metric.py
+++ b/opentelemetry-instrumentation/src/opentelemetry/instrumentation/metric.py
@@ -53,9 +53,7 @@ class HTTPMetricRecorder(MetricRecorder):
     """Metric recorder for http instrumentations. Tracks duration."""
 
     def __init__(
-        self,
-        meter: Optional[metrics.Meter],
-        http_type: HTTPMetricType,
+        self, meter: Optional[metrics.Meter], http_type: HTTPMetricType,
     ):
         super().__init__(meter)
         self._http_type = http_type
diff --git a/opentelemetry-instrumentation/tests/test_metric.py b/opentelemetry-instrumentation/tests/test_metric.py
index 5d11dbb9b4e..14c39d85e09 100644
--- a/opentelemetry-instrumentation/tests/test_metric.py
+++ b/opentelemetry-instrumentation/tests/test_metric.py
@@ -61,8 +61,12 @@ def test_ctor(self):
         recorder = HTTPMetricRecorder(meter, HTTPMetricType.CLIENT)
         # pylint: disable=protected-access
         self.assertEqual(recorder._http_type, HTTPMetricType.CLIENT)
-        self.assertTrue(isinstance(recorder._client_duration, metrics.ValueRecorder))
-        self.assertEqual(recorder._client_duration.name, "http.client.duration")
+        self.assertTrue(
+            isinstance(recorder._client_duration, metrics.ValueRecorder)
+        )
+        self.assertEqual(
+            recorder._client_duration.name, "http.client.duration"
+        )
         self.assertEqual(
             recorder._client_duration.description,
             "measures the duration of the outbound HTTP request",
@@ -72,18 +76,26 @@ def test_ctor_types(self):
         meter = metrics_api.get_meter(__name__)
         recorder = HTTPMetricRecorder(meter, HTTPMetricType.CLIENT)
         self.assertEqual(recorder._http_type, HTTPMetricType.CLIENT)
-        self.assertTrue(isinstance(recorder._client_duration, metrics.ValueRecorder))
+        self.assertTrue(
+            isinstance(recorder._client_duration, metrics.ValueRecorder)
+        )
         self.assertIsNone(recorder._server_duration)
 
         recorder = HTTPMetricRecorder(meter, HTTPMetricType.SERVER)
         self.assertEqual(recorder._http_type, HTTPMetricType.SERVER)
-        self.assertTrue(isinstance(recorder._server_duration, metrics.ValueRecorder))
+        self.assertTrue(
+            isinstance(recorder._server_duration, metrics.ValueRecorder)
+        )
         self.assertIsNone(recorder._client_duration)
 
         recorder = HTTPMetricRecorder(meter, HTTPMetricType.BOTH)
         self.assertEqual(recorder._http_type, HTTPMetricType.BOTH)
-        self.assertTrue(isinstance(recorder._client_duration, metrics.ValueRecorder))
-        self.assertTrue(isinstance(recorder._server_duration, metrics.ValueRecorder))
+        self.assertTrue(
+            isinstance(recorder._client_duration, metrics.ValueRecorder)
+        )
+        self.assertTrue(
+            isinstance(recorder._server_duration, metrics.ValueRecorder)
+        )
 
     def test_record_client_duration(self):
         meter = metrics_api.get_meter(__name__)

From ccfba2f8885e6dd094eab5f16e1b9a9bd6f6b923 Mon Sep 17 00:00:00 2001
From: Leighton <lechen@microsoft.com>
Date: Mon, 12 Oct 2020 16:12:29 -0400
Subject: [PATCH 06/12] lint

---
 .../src/opentelemetry/instrumentation/django/middleware.py       | 1 -
 1 file changed, 1 deletion(-)

diff --git a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
index bc6e28cbe27..6a6c2d200be 100644
--- a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
+++ b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
@@ -13,7 +13,6 @@
 # limitations under the License.
 
 import time
-
 from logging import getLogger
 
 from django.conf import settings

From 24cf8ff197ecfb25374ef5f8348607687b651561 Mon Sep 17 00:00:00 2001
From: Leighton <lechen@microsoft.com>
Date: Mon, 12 Oct 2020 16:21:45 -0400
Subject: [PATCH 07/12] Update middleware.py

---
 .../src/opentelemetry/instrumentation/django/middleware.py      | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
index 6a6c2d200be..47f262515c3 100644
--- a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
+++ b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
@@ -207,6 +207,6 @@ def process_response(self, request, response):
                     request.start_time, time.time(), request.labels
                 )
         except Exception as ex:  # pylint: disable=W0703
-            _logger.warning("Error recording duration metrics: {}", ex)
+            _logger.warning("Error recording duration metrics: %s", ex)
 
         return response

From b2bf95765f76f90d6cc8744e087749560277b765 Mon Sep 17 00:00:00 2001
From: Leighton <lechen@microsoft.com>
Date: Tue, 13 Oct 2020 10:54:45 -0400
Subject: [PATCH 08/12] address comments

---
 .../instrumentation/django/middleware.py      | 38 ++++++++-----------
 1 file changed, 16 insertions(+), 22 deletions(-)

diff --git a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
index 47f262515c3..4bd5c677818 100644
--- a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
+++ b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
@@ -90,28 +90,22 @@ def _get_span_name(request):
         except Resolver404:
             return "HTTP {}".format(request.method)
 
+    _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']
+    ]
+
     @staticmethod
     def _get_metric_labels_from_attributes(attributes):
         labels = {}
         labels["http.method"] = attributes.get("http.method", "")
-        if attributes.get("http.url"):
-            labels["http.url"] = attributes.get("http.url")
-        elif attributes.get("http.scheme"):
-            labels["http.scheme"] = attributes.get("http.scheme")
-            if attributes.get("http.target"):
-                labels["http.target"] = attributes.get("http.target")
-                if attributes.get("http.host"):
-                    labels["http.host"] = attributes.get("http.host")
-                elif attributes.get("net.host.port"):
-                    labels["net.host.port"] = attributes.get("net.host.port")
-                    if attributes.get("http.server_name"):
-                        labels["http.server_name"] = attributes.get(
-                            "http.server_name"
-                        )
-                    elif attributes.get("http.host.name"):
-                        labels["http.host.name"] = attributes.get(
-                            "http.host.name"
-                        )
+        for attrs in _attributes_by_preference:
+            labels_from_attributes = {attr: attributes.get(attr, None) for attr in attrs}
+            if all(labels_from_attributes.values()):
+                labels.update(labels_from_attributes)
+                break
         if attributes.get("http.flavor"):
             labels["http.flavor"] = attributes.get("http.flavor")
         return labels
@@ -124,7 +118,7 @@ def process_request(self, request):
         if self._excluded_urls.url_disabled(request.build_absolute_uri("?")):
             return
 
-        request.start_time = time.time()
+        request._otel_start_time = time.time()
 
         environ = request.META
 
@@ -141,7 +135,7 @@ def process_request(self, request):
         )
 
         attributes = collect_request_attributes(environ)
-        request.labels = self._get_metric_labels_from_attributes(attributes)
+        request._otel_labels = self._get_metric_labels_from_attributes(attributes)
 
         if span.is_recording():
             attributes = extract_attributes_from_object(
@@ -188,7 +182,7 @@ def process_response(self, request, response):
                 "{} {}".format(response.status_code, response.reason_phrase),
                 response,
             )
-            request.labels["http.status_code"] = str(response.status_code)
+            request._otel_labels["http.status_code"] = str(response.status_code)
             request.META.pop(self._environ_span_key)
 
             request.META[self._environ_activation_key].__exit__(
@@ -204,7 +198,7 @@ def process_response(self, request, response):
             metric_recorder = getattr(settings, "OTEL_METRIC_RECORDER", None)
             if metric_recorder:
                 metric_recorder.record_server_duration_range(
-                    request.start_time, time.time(), request.labels
+                    request._otel_start_time, time.time(), request._otel_labels
                 )
         except Exception as ex:  # pylint: disable=W0703
             _logger.warning("Error recording duration metrics: %s", ex)

From 6255c9490f158560fbde12f6e4f89e2f942cd2eb Mon Sep 17 00:00:00 2001
From: Leighton <lechen@microsoft.com>
Date: Tue, 13 Oct 2020 11:17:45 -0400
Subject: [PATCH 09/12] fix test

---
 .../instrumentation/django/middleware.py      | 27 +++++++++++--------
 1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
index 4bd5c677818..badad860805 100644
--- a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
+++ b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
@@ -44,6 +44,12 @@
     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):
@@ -90,19 +96,14 @@ def _get_span_name(request):
         except Resolver404:
             return "HTTP {}".format(request.method)
 
-    _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']
-    ]
-
     @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}
+        for attrs in _ATTRIBUTES_BY_PREFERENCE:
+            labels_from_attributes = {
+                attr: attributes.get(attr, None) for attr in attrs
+            }
             if all(labels_from_attributes.values()):
                 labels.update(labels_from_attributes)
                 break
@@ -135,7 +136,9 @@ def process_request(self, request):
         )
 
         attributes = collect_request_attributes(environ)
-        request._otel_labels = self._get_metric_labels_from_attributes(attributes)
+        request._otel_labels = self._get_metric_labels_from_attributes(
+            attributes
+        )
 
         if span.is_recording():
             attributes = extract_attributes_from_object(
@@ -182,7 +185,9 @@ def process_response(self, request, response):
                 "{} {}".format(response.status_code, response.reason_phrase),
                 response,
             )
-            request._otel_labels["http.status_code"] = str(response.status_code)
+            request._otel_labels["http.status_code"] = str(
+                response.status_code
+            )
             request.META.pop(self._environ_span_key)
 
             request.META[self._environ_activation_key].__exit__(

From 720ed3a1edc90f3368ae96b3dff2eac807749c42 Mon Sep 17 00:00:00 2001
From: Leighton <lechen@microsoft.com>
Date: Tue, 13 Oct 2020 11:27:18 -0400
Subject: [PATCH 10/12] Update middleware.py

---
 .../opentelemetry/instrumentation/django/middleware.py    | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
index badad860805..904551e5eb8 100644
--- a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
+++ b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
@@ -45,10 +45,10 @@
 
 _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'],
+    ["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"],
 ]
 
 

From f25d2d88e972fb8e48935a1985c138f3e241be7d Mon Sep 17 00:00:00 2001
From: Leighton <lechen@microsoft.com>
Date: Tue, 13 Oct 2020 11:34:51 -0400
Subject: [PATCH 11/12] Update middleware.py

---
 .../src/opentelemetry/instrumentation/django/middleware.py    | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
index 904551e5eb8..ea700a0d1f6 100644
--- a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
+++ b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
@@ -119,6 +119,7 @@ def process_request(self, request):
         if self._excluded_urls.url_disabled(request.build_absolute_uri("?")):
             return
 
+        # pylint:disable=W0212
         request._otel_start_time = time.time()
 
         environ = request.META
@@ -136,6 +137,7 @@ def process_request(self, request):
         )
 
         attributes = collect_request_attributes(environ)
+        # pylint:disable=W0212
         request._otel_labels = self._get_metric_labels_from_attributes(
             attributes
         )
@@ -185,6 +187,7 @@ def process_response(self, request, response):
                 "{} {}".format(response.status_code, response.reason_phrase),
                 response,
             )
+            # pylint:disable=W0212
             request._otel_labels["http.status_code"] = str(
                 response.status_code
             )
@@ -202,6 +205,7 @@ def process_response(self, request, response):
         try:
             metric_recorder = getattr(settings, "OTEL_METRIC_RECORDER", None)
             if metric_recorder:
+                # pylint:disable=W0212
                 metric_recorder.record_server_duration_range(
                     request._otel_start_time, time.time(), request._otel_labels
                 )

From 4790aecae79ef8a4ea3241fcdcdc02c970dc02de Mon Sep 17 00:00:00 2001
From: Leighton <lechen@microsoft.com>
Date: Wed, 14 Oct 2020 13:45:46 -0400
Subject: [PATCH 12/12] address comments

---
 .../opentelemetry/instrumentation/django/middleware.py    | 8 ++++----
 .../src/opentelemetry/instrumentation/metric.py           | 6 +++---
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
index ea700a0d1f6..b7986fb9a9e 100644
--- a/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
+++ b/instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py
@@ -44,7 +44,7 @@
     MiddlewareMixin = object
 
 _logger = getLogger(__name__)
-_ATTRIBUTES_BY_PREFERENCE = [
+_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"],
@@ -100,11 +100,11 @@ def _get_span_name(request):
     def _get_metric_labels_from_attributes(attributes):
         labels = {}
         labels["http.method"] = attributes.get("http.method", "")
-        for attrs in _ATTRIBUTES_BY_PREFERENCE:
+        for attrs in _attributes_by_preference:
             labels_from_attributes = {
                 attr: attributes.get(attr, None) for attr in attrs
             }
-            if all(labels_from_attributes.values()):
+            if set(attrs).issubset(attributes.keys()):
                 labels.update(labels_from_attributes)
                 break
         if attributes.get("http.flavor"):
@@ -204,7 +204,7 @@ def process_response(self, request, response):
 
         try:
             metric_recorder = getattr(settings, "OTEL_METRIC_RECORDER", None)
-            if metric_recorder:
+            if metric_recorder is not None:
                 # pylint:disable=W0212
                 metric_recorder.record_server_duration_range(
                     request._otel_start_time, time.time(), request._otel_labels
diff --git a/opentelemetry-instrumentation/src/opentelemetry/instrumentation/metric.py b/opentelemetry-instrumentation/src/opentelemetry/instrumentation/metric.py
index 3a58c6d031d..6aaca0bcaa0 100644
--- a/opentelemetry-instrumentation/src/opentelemetry/instrumentation/metric.py
+++ b/opentelemetry-instrumentation/src/opentelemetry/instrumentation/metric.py
@@ -59,7 +59,7 @@ def __init__(
         self._http_type = http_type
         self._client_duration = None
         self._server_duration = None
-        if self._meter:
+        if self._meter is not None:
             if http_type in (HTTPMetricType.CLIENT, HTTPMetricType.BOTH):
                 self._client_duration = self._meter.create_metric(
                     name="{}.{}.duration".format("http", "client"),
@@ -90,7 +90,7 @@ def record_client_duration(self, labels: Dict[str, str]):
     def record_client_duration_range(
         self, start_time, end_time, labels: Dict[str, str]
     ):
-        if self._client_duration:
+        if self._client_duration is not None:
             elapsed_time = (end_time - start_time) * 1000
             self._client_duration.record(elapsed_time, labels)
 
@@ -105,6 +105,6 @@ def record_server_duration(self, labels: Dict[str, str]):
     def record_server_duration_range(
         self, start_time, end_time, labels: Dict[str, str]
     ):
-        if self._server_duration:
+        if self._server_duration is not None:
             elapsed_time = (end_time - start_time) * 1000
             self._server_duration.record(elapsed_time, labels)