Closes #11453: Display a warning banner when DEBUG is enabled

docs/configuration/development.md

@@ -18,4 +18,4 @@ interface.
 
 Default: False
 
-This parameter serves as a safeguard to prevent some potentially dangerous behavior, such as generating new database schema migrations. Set this to `True` **only** if you are actively developing the NetBox code base.
+This parameter serves as a safeguard to prevent some potentially dangerous behavior, such as generating new database schema migrations. Additionally, enabling this setting disables the debug warning banner in the UI. Set this to `True` **only** if you are actively developing the NetBox code base.

docs/release-notes/version-3.4.md

@@ -4,11 +4,13 @@
 
 ### Enhancements
 
+* [#11453](https://github.com/netbox-community/netbox/issues/11453) - Display a warning banner when `DEBUG` is enabled
 * [#12007](https://github.com/netbox-community/netbox/issues/12007) - Enable filtering of VM Interfaces by assigned VLAN
 * [#12095](https://github.com/netbox-community/netbox/issues/12095) - Specify UTF-8 encoding for default export template MIME type
 
 ### Bug Fixes
 
+* [#10615](https://github.com/netbox-community/netbox/issues/10615) - Fix filtering of cable terminations by A/B end
 * [#11746](https://github.com/netbox-community/netbox/issues/11746) - Fix cleanup of object data when deleting a custom field
 * [#12011](https://github.com/netbox-community/netbox/issues/12011) - Fix KeyError exception when attempting to add module bays in bulk
 * [#12074](https://github.com/netbox-community/netbox/issues/12074) - Fix the automatic assignment of racks to devices via the REST API

netbox/templates/base/layout.html

@@ -70,10 +70,17 @@ Blocks:
           </div>
         {% endif %}
 
+        {% if settings.DEBUG and not settings.DEVELOPER %}
+          <div class="alert alert-warning text-center mx-3" role="alert">
+            <strong><i class="mdi mdi-alert"></i> Debug mode is enabled.</strong>
+            Performance may be limited. Debugging should never be enabled on a production system.
+          </div>
+        {% endif %}
+
         {% if config.MAINTENANCE_MODE %}
           <div class="alert alert-warning text-center mx-3" role="alert">
-            <h4><i class="mdi mdi-alert"></i> Maintenance Mode</h4>
-            <span>NetBox is currently in maintenance mode. Functionality may be limited.</span>
+            <h5><i class="mdi mdi-alert"></i> Maintenance Mode</h5>
+            NetBox is currently in maintenance mode. Functionality may be limited.
           </div>
         {% endif %}