RecursionError in netbox_custom_objects plugin due to circular dependencies in CustomObjectType Fields

[Kani999]

Plugin Version

v0.2.0

NetBox Version

v4.4.0-beta1

Python Version

v3.12.3

Steps to Reproduce

1. Create two CustomObjectType instances (e.g., Service and ServiceEndpoint).
2. Add fields:
   • In Service, add an object type field pointing to ServiceEndpoint.
   • In ServiceEndpoint, add an object type field pointing back to Service.
3. Access a NetBox page
4. Observe the 500 Internal Server Error in logs.

Infinite recursion in the netbox_custom_objects plugin, specifically during template rendering for navigation. The recursion happens between CustomObjectType.get_model() and FieldType.get_model_field(), where each method repeatedly calls the other, leading to a stack overflow.

Expected Behavior

• Validation error when creating a circular dependency in custom object definitions.
• NetBox loads pages without errors, and custom objects resolve correctly without recursion.

Observed Behavior

• RecursionError in Django logs, originating from CustomObjectType.get_model() → _fetch_and_generate_field_attrs() → get_model_field().
• nbshell scripts attempting to inspect or delete fields also fail with recursion

[Kani999]

QuickFix

• Resolved by deleting problematic fields using raw SQL to bypass model generation.

• How to Fix It:
  Use raw SQL to delete circular fields:

     DELETE FROM netbox_custom_objects_customobjecttypefield
     WHERE custom_object_type_id = [ID] AND name = '[field_name]';