Potential error when running remove_stale_contenttypes

[peteeckel]

After upgrading to NetBox DNS 1.1.0, in some cases invocations of manage.py remove_stale_contenttypes fail with an exception:

Removing stale content types (python3 netbox/manage.py remove_stale_contenttypes --no-input)...
Traceback (most recent call last):
  File "/opt/netbox-4.1.0/netbox/manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/opt/netbox-4.1.0/venv/lib/python3.11/site-packages/django/core/management/__init__.py", line 442, in execute_from_command_line
    utility.execute()
  File "/opt/netbox-4.1.0/venv/lib/python3.11/site-packages/django/core/management/__init__.py", line 436, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/opt/netbox-4.1.0/venv/lib/python3.11/site-packages/django/core/management/base.py", line 413, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/opt/netbox-4.1.0/venv/lib/python3.11/site-packages/django/core/management/base.py", line 459, in execute
    output = self.handle(*args, **options)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/netbox-4.1.0/venv/lib/python3.11/site-packages/django/contrib/contenttypes/management/commands/remove_stale_contenttypes.py", line 101, in handle
    ct.delete()
  File "/opt/netbox-4.1.0/venv/lib/python3.11/site-packages/django/db/models/base.py", line 1182, in delete
    collector.collect([self], keep_parents=keep_parents)
  File "/opt/netbox-4.1.0/venv/lib/python3.11/site-packages/django/db/models/deletion.py", line 355, in collect
    raise ProtectedError(
django.db.models.deletion.ProtectedError: ("Cannot delete some instances of model 'ContentType' because they are referenced through protected foreign keys: 'ObjectChange.changed_object_type'.", {<ObjectChange: contact SOME-IDENTIFIER (Some Name) created by [email protected]>})

This is also mentioned in NetBox issue netbox-community/netbox#17361.

This is caused by the renaming of the Contact model to RegistrationContact, possibly in combination with recent internal changes in NetBox.

The workaround to clean up that issue is to run dbshell and remove the orphaned entries from the ObjectChange data:

It is advisable to have a backup available when working directly on the database!

(venv) # /opt/netbox/netbox/manage.py dbshell
DELETE FROM core_objectchange WHERE changed_object_type_id in (
    SELECT id FROM django_content_type WHERE app_label='netbox_dns' AND model='contact'
);

It is advisable to have a backup available when working directly on the database!

This is not happening for everyone. If you do not use registration contacts or don't have any changes in the change log (expiry is by default set to 90 days) you will not be affected.

[peteeckel]

This has been addressed in the migration that renames Contact to RegistrationContact and will be fixed in release 1.1.1.