Adding try catch to fix ImproperlyConfigured exception while allowing (#1369)

Author: jeremydvoss

CHANGELOG.md

@@ -9,6 +9,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- `opentelemetry-instrumentation-django` Fixed bug where auto-instrumentation fails when django is installed and settings are not configured.
+  ([#1369](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/1369))
 - `opentelemetry-instrumentation-system-metrics` add supports to collect system thread count. ([#1339](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/1339))
 
 ## [1.13.0-0.34b0](https://github.com/open-telemetry/opentelemetry-python/releases/tag/v1.13.0-0.34b0) - 2022-09-26

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

@@ -195,6 +195,7 @@ def response_hook(span, request, response):
 
 from django import VERSION as django_version
 from django.conf import settings
+from django.core.exceptions import ImproperlyConfigured
 
 from opentelemetry.instrumentation.django.environment_variables import (
     OTEL_PYTHON_DJANGO_INSTRUMENT,
@@ -275,7 +276,23 @@ def _instrument(self, **kwargs):
         # https://docs.djangoproject.com/en/3.0/ref/middleware/#middleware-ordering
 
         _middleware_setting = _get_django_middleware_setting()
-        settings_middleware = getattr(settings, _middleware_setting, [])
+        settings_middleware = []
+        try:
+            settings_middleware = getattr(settings, _middleware_setting, [])
+        except ImproperlyConfigured as exception:
+            _logger.debug(
+                "DJANGO_SETTINGS_MODULE environment variable not configured. Defaulting to empty settings: %s",
+                exception,
+            )
+            settings.configure()
+            settings_middleware = getattr(settings, _middleware_setting, [])
+        except ModuleNotFoundError as exception:
+            _logger.debug(
+                "DJANGO_SETTINGS_MODULE points to a non-existent module. Defaulting to empty settings: %s",
+                exception,
+            )
+            settings.configure()
+            settings_middleware = getattr(settings, _middleware_setting, [])
 
         # Django allows to specify middlewares as a tuple, so we convert this tuple to a
         # list, otherwise we wouldn't be able to call append/remove