Add exception tracing to django middleware (#885)

Author: tonybaloney

contrib/opencensus-ext-django/CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ## Unreleased
 
+- Add exception tracing to django middleware
+([#885](https://github.com/census-instrumentation/opencensus-python/pull/885))
+
 ## 0.7.4
 Released 2021-01-19
 

contrib/opencensus-ext-django/opencensus/ext/django/middleware.py

@@ -16,6 +16,8 @@
 import six
 
 import logging
+import sys
+import traceback
 
 import django
 import django.conf
@@ -42,6 +44,9 @@
 HTTP_ROUTE = attributes_helper.COMMON_ATTRIBUTES['HTTP_ROUTE']
 HTTP_URL = attributes_helper.COMMON_ATTRIBUTES['HTTP_URL']
 HTTP_STATUS_CODE = attributes_helper.COMMON_ATTRIBUTES['HTTP_STATUS_CODE']
+ERROR_MESSAGE = attributes_helper.COMMON_ATTRIBUTES['ERROR_MESSAGE']
+ERROR_NAME = attributes_helper.COMMON_ATTRIBUTES['ERROR_NAME']
+STACKTRACE = attributes_helper.COMMON_ATTRIBUTES['STACKTRACE']
 
 REQUEST_THREAD_LOCAL_KEY = 'django_request'
 SPAN_THREAD_LOCAL_KEY = 'django_span'
@@ -267,3 +272,29 @@ def process_response(self, request, response):
             log.error('Failed to trace request', exc_info=True)
         finally:
             return response
+
+    def process_exception(self, request, exception):
+        # Do not trace if the url is excluded
+        if utils.disable_tracing_url(request.path, self.excludelist_paths):
+            return
+
+        try:
+            if hasattr(exception, '__traceback__'):
+                tb = exception.__traceback__
+            else:
+                _, _, tb = sys.exc_info()
+
+            span = _get_django_span()
+            span.add_attribute(
+                attribute_key=ERROR_NAME,
+                attribute_value=exception.__class__.__name__)
+            span.add_attribute(
+                attribute_key=ERROR_MESSAGE,
+                attribute_value=str(exception))
+            span.add_attribute(
+                attribute_key=STACKTRACE,
+                attribute_value='\n'.join(traceback.format_tb(tb)))
+
+            _set_django_attributes(span, request)
+        except Exception:  # pragma: NO COVER
+            log.error('Failed to trace request', exc_info=True)

contrib/opencensus-ext-django/tests/test_django_middleware.py

@@ -12,6 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import sys
+import traceback
 import unittest
 
 import mock
@@ -291,6 +293,73 @@ def test_process_response_unfinished_child_span(self):
 
         self.assertEqual(span.attributes, expected_attributes)
 
+    def test_process_exception(self):
+        from opencensus.ext.django import middleware
+
+        trace_id = '2dd43a1d6b2549c6bc2a1a54c2fc0b05'
+        span_id = '6e0c63257de34c92'
+        django_trace_id = '00-{}-{}-00'.format(trace_id, span_id)
+
+        django_request = RequestFactory().get('/wiki/Rabbit', **{
+            'traceparent': django_trace_id,
+        })
+
+        # Force the test request to be sampled
+        settings = type('Test', (object,), {})
+        settings.OPENCENSUS = {
+            'TRACE': {
+                'SAMPLER': 'opencensus.trace.samplers.AlwaysOnSampler()',  # noqa
+            }
+        }
+        patch_settings = mock.patch(
+            'django.conf.settings',
+            settings)
+
+        with patch_settings:
+            middleware_obj = middleware.OpencensusMiddleware()
+
+        tb = None
+        try:
+            raise RuntimeError("bork bork bork")
+        except Exception as exc:
+            test_exception = exc
+            if hasattr(exc, "__traceback__"):
+                tb = exc.__traceback__
+            else:
+                _, _, tb = sys.exc_info()
+
+        middleware_obj.process_request(django_request)
+        tracer = middleware._get_current_tracer()
+        span = tracer.current_span()
+
+        exporter_mock = mock.Mock()
+        tracer.exporter = exporter_mock
+
+        django_response = mock.Mock()
+        django_response.status_code = 200
+
+        expected_attributes = {
+            'http.host': u'testserver',
+            'http.method': 'GET',
+            'http.path': u'/wiki/Rabbit',
+            'http.route': u'/wiki/Rabbit',
+            'http.url': u'http://testserver/wiki/Rabbit',
+            'django.user.id': '123',
+            'django.user.name': 'test_name',
+            'error.name': "RuntimeError",
+            'error.message': 'bork bork bork',
+            'stacktrace': '\n'.join(traceback.format_tb(tb))
+        }
+
+        mock_user = mock.Mock()
+        mock_user.pk = 123
+        mock_user.get_username.return_value = 'test_name'
+        django_request.user = mock_user
+
+        middleware_obj.process_exception(django_request, test_exception)
+
+        self.assertEqual(span.attributes, expected_attributes)
+
 
 class Test__set_django_attributes(unittest.TestCase):
     class Span(object):

contrib/opencensus-ext-sqlalchemy/setup.py

@@ -40,7 +40,7 @@
     long_description=open('README.rst').read(),
     install_requires=[
         'opencensus >= 0.8.dev0, < 1.0.0',
-        'SQLAlchemy >= 1.1.14, < 2.0.0',
+        'SQLAlchemy >= 1.1.14, < 1.3.24',  # https://github.com/sqlalchemy/sqlalchemy/issues/6168 # noqa: E501
     ],
     extras_require={},
     license='Apache-2.0',