Unable to delete device after upgrade to 2.4.3

[jnfohr]

Environment

• Python version: 3.5.2
• NetBox version: 2.4.3

Steps to Reproduce

• Upgrade from 2.3.6 to 2.4.3
• Clic "Delete this device" from web UI for an already existing device and hit "Confirm"

Expected Behavior

• Deletion of the device

Observed Behavior

Error message:

<class 'dcim.models.DoesNotExist'>

Device matching query does not exist.

And device is not deleted. This is not happening for all existing devices.

Stacktrace

Internal Server Error: /dcim/devices/187/delete/

DoesNotExist at /dcim/devices/187/delete/
Device matching query does not exist.

Request Method: POST
Request URL: http://netbox/dcim/devices/187/delete/
Django Version: 2.0.8
Python Executable: /usr/bin/python3
Python Version: 3.5.2
Python Path: ['/opt/netbox/netbox', '/opt/netbox/netbox', '/usr/local/bin', '/usr/lib/python35.zip', '/usr/lib/python3.5', '/usr/lib/python3.5/plat-x86_64-linux-gnu', '/usr/lib/python3.5/lib-dynload', '/usr/local/lib/python3.5/dist-packages', '/usr/lib/python3/dist-packages']
Server time: Mon, 13 Aug 2018 13:35:04 +0000
Installed Applications:
['django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'django.contrib.humanize',
 'corsheaders',
 'debug_toolbar',
 'django_filters',
 'django_tables2',
 'mptt',
 'rest_framework',
 'taggit',
 'taggit_serializer',
 'timezone_field',
 'circuits',
 'dcim',
 'ipam',
 'extras',
 'secrets',
 'tenancy',
 'users',
 'utilities',
 'virtualization',
 'drf_yasg']
Installed Middleware:
('debug_toolbar.middleware.DebugToolbarMiddleware',
 'corsheaders.middleware.CorsMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware',
 'django.middleware.security.SecurityMiddleware',
 'utilities.middleware.ExceptionHandlingMiddleware',
 'utilities.middleware.LoginRequiredMiddleware',
 'utilities.middleware.APIVersionMiddleware',
 'extras.middleware.ObjectChangeMiddleware')


Traceback:

File "/usr/local/lib/python3.5/dist-packages/django/db/models/fields/related_descriptors.py" in __get__
  158.             rel_obj = self.field.get_cached_value(instance)

File "/usr/local/lib/python3.5/dist-packages/django/db/models/fields/mixins.py" in get_cached_value
  13.             return instance._state.fields_cache[cache_name]

During handling of the above exception ('device'), another exception occurred:

File "/usr/local/lib/python3.5/dist-packages/django/core/handlers/exception.py" in inner
  35.             response = get_response(request)

File "/usr/local/lib/python3.5/dist-packages/django/core/handlers/base.py" in _get_response
  128.                 response = self.process_exception_by_middleware(e, request)

File "/usr/local/lib/python3.5/dist-packages/django/core/handlers/base.py" in _get_response
  126.                 response = wrapped_callback(request, *callback_args, **callback_kwargs)

File "/usr/local/lib/python3.5/dist-packages/django/views/generic/base.py" in view
  69.             return self.dispatch(request, *args, **kwargs)

File "/usr/local/lib/python3.5/dist-packages/django/contrib/auth/mixins.py" in dispatch
  85.         return super().dispatch(request, *args, **kwargs)

File "/usr/local/lib/python3.5/dist-packages/django/views/generic/base.py" in dispatch
  89.         return handler(request, *args, **kwargs)

File "/opt/netbox/netbox/utilities/views.py" in post
  280.                 obj.delete()

File "/usr/local/lib/python3.5/dist-packages/django/db/models/base.py" in delete
  891.         return collector.delete()

File "/usr/local/lib/python3.5/dist-packages/django/db/models/deletion.py" in delete
  307.                             sender=model, instance=obj, using=self.using

File "/usr/local/lib/python3.5/dist-packages/django/dispatch/dispatcher.py" in send
  178.             for receiver in self._live_receivers(sender)

File "/usr/local/lib/python3.5/dist-packages/django/dispatch/dispatcher.py" in <listcomp>
  178.             for receiver in self._live_receivers(sender)

File "/usr/local/lib/python3.5/dist-packages/django/utils/functional.py" in _curried
  11.         return _curried_func(*(args + moreargs), **dict(kwargs, **morekwargs))

File "/opt/netbox/netbox/extras/middleware.py" in _record_object_deleted
  37.         instance.log_change(request.user, request.id, OBJECTCHANGE_ACTION_DELETE)

File "/opt/netbox/netbox/dcim/models.py" in log_change
  2088.                 related_object=interface.parent,

File "/opt/netbox/netbox/dcim/models.py" in parent
  1960.         return self.device or self.virtual_machine

File "/usr/local/lib/python3.5/dist-packages/django/db/models/fields/related_descriptors.py" in __get__
  164.                 rel_obj = self.get_object(instance)

File "/usr/local/lib/python3.5/dist-packages/django/db/models/fields/related_descriptors.py" in get_object
  139.         return qs.get(self.field.get_reverse_related_filter(instance))

File "/usr/local/lib/python3.5/dist-packages/django/db/models/query.py" in get
  403.                 self.model._meta.object_name

Exception Type: DoesNotExist at /dcim/devices/187/delete/
Exception Value: Device matching query does not exist.

[jeremystretch]

This is not happening for all existing devices.

Could you please list the steps necessary to recreate the error, beginning with the creation of a new device? This is necessary to develop a fix.

Looks related to #2323.

[jnfohr]

When creating a new device i'm not able to recreate the issue.

I'v been doing some tests and found out that the error disappears and i'm able to delete the device once i disconnect or delete the network interfaces (disconnect is enough). But changing the network interface parameters (name, status, type) has no effect.

What's surprising is that it just occurs with a few devices and is hardly reproductible. Deleting the switch facing the device while the interfaces are connected is possible and does not return any error.

[jeremystretch]

I can't recreate this but we should be able to avoid it by catching the exception in InterfaceConnection.log_change().