Use environment variable from module

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

@@ -19,6 +19,9 @@
 
 from opentelemetry.instrumentation.django.middleware import _DjangoMiddleware
 from opentelemetry.instrumentation.django.version import __version__
+from opentelemetry.instrumentation.django.environment_variables import (
+    OTEL_PYTHON_DJANGO_INSTRUMENT
+)
 from opentelemetry.instrumentation.instrumentor import BaseInstrumentor
 from opentelemetry.instrumentation.metric import (
     HTTPMetricRecorder,
@@ -43,7 +46,7 @@ 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.
-        if environ.get("OTEL_PYTHON_DJANGO_INSTRUMENT") == "False":
+        if environ.get(OTEL_PYTHON_DJANGO_INSTRUMENT) == "False":
             return
 
         # This can not be solved, but is an inherent problem of this approach:

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

@@ -0,0 +1,15 @@
+# Copyright The OpenTelemetry Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+OTEL_PYTHON_DJANGO_INSTRUMENT = "OTEL_PYTHON_DJANGO_INSTRUMENT"