Enforce new SECRET_KEY in production environments
The server should refuse to start if the SECRET_KEY does not differ from the default value in our repository.

The importance of this issue depends on whether the Federated Cloud feature is using this key or not.
diff --git a/backend/cms/apps.py b/backend/cms/apps.py
index 3c1abd7f3..ad324df24 100644
--- a/backend/cms/apps.py
+++ b/backend/cms/apps.py
@@ -1,8 +1,12 @@
 """
 Django related class representing a config of an app
 """
+import logging
+import sys
+from django.conf import settings
 from django.apps import AppConfig
 
+logger = logging.getLogger(__name__)
 
 class CmsConfig(AppConfig):
     """
@@ -10,3 +14,8 @@ class CmsConfig(AppConfig):
     """
 
     name = 'cms'
+
+    def ready(self):
+        if settings.SECRET_KEY == '-!v282$zj815_q@htaxcubylo)(l%a+k*-xi78hw*#s2@i86@_' and not settings.DEBUG:
+            logger.error("You are running the Integreat CMS in production mode. Change the SECRET_KEY in the settings.py!")
+            sys.exit(1)
['backend/cms/apps.py']