django-rest-framework v3.11 dropped suppport for set_context in UniqueTogetherValidator

[Links2004]

Environment

• Python version: 3.7.3
• NetBox version: 2.8.0 and master

When we try to create a vlan via the RESTapi the result is 500 when we try to set the group,
we tested this with v2.8.0 and master branch,
before the update from v2.7.8 this where working fine.

Steps to Reproduce

1. Disable any installed plugins by commenting out the PLUGINS setting in
   configuration.py.
2. create site KAR-DC
3. create VLAN groups
   GET "api/ipam/vlan-groups/"

{
  "count": 2,
  "next": null,
  "previous": null,
  "results": [
    {
      "id": 1,
      "name": "C01",
      "slug": "c01",
      "site": {
        "id": 1,
        "url": "http://xxx/api/dcim/sites/1/",
        "name": "KAR-DC",
        "slug": "kar-dc"
      },
      "description": "",
      "vlan_count": 13
    },
    {
      "id": 2,
      "name": "QA",
      "slug": "qa",
      "site": {
        "id": 1,
        "url": "http://xxx/api/dcim/sites/1/",
        "name": "KAR-DC",
        "slug": "kar-dc"
      },
      "description": "",
      "vlan_count": 2
    }
  ]
}

4. send POST

curl -X POST "http://xxx/api/ipam/vlans/" -H "accept: application/json" -H "Content-Type: application/json" -H "X-CSRFToken: " -d "{ \"vid\": 3098, \"name\": \"sgu-8-lan\", \"group\": { \"slug\": \"c01\" }}"

Expected Behavior

VLAN is created

Observed Behavior

error:

AttributeError at /api/ipam/vlans/
'UniqueTogetherValidator' object has no attribute 'set_context'

Request Method: POST
Request URL: http://10.0.192.20/api/ipam/vlans/
Django Version: 3.0.5
Python Executable: /opt/netbox/venv/bin/python3
Python Version: 3.7.3
Python Path: ['/opt/netbox/venv/bin', '/opt/netbox/netbox', '/', '/usr/lib/python37.zip', '/usr/lib/python3.7', '/usr/lib/python3.7/lib-dynload', '/opt/netbox/venv/lib/python3.7/site-packages']
Server time: Wed, 15 Apr 2020 10:01:42 +0000
Installed Applications:
['django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'django.contrib.humanize',
 'cacheops',
 'corsheaders',
 'debug_toolbar',
 'django_filters',
 'django_tables2',
 'django_prometheus',
 'mptt',
 'rest_framework',
 'taggit',
 'taggit_serializer',
 'timezone_field',
 'circuits',
 'dcim',
 'ipam',
 'extras',
 'secrets',
 'tenancy',
 'users',
 'utilities',
 'virtualization',
 'django_rq',
 'drf_yasg']
Installed Middleware:
['debug_toolbar.middleware.DebugToolbarMiddleware',
 'django_prometheus.middleware.PrometheusBeforeMiddleware',
 '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.RemoteUserMiddleware',
 'utilities.middleware.LoginRequiredMiddleware',
 'utilities.middleware.APIVersionMiddleware',
 'extras.middleware.ObjectChangeMiddleware',
 'django_prometheus.middleware.PrometheusAfterMiddleware']


Traceback (most recent call last):
  File "/opt/netbox/venv/lib/python3.7/site-packages/django/core/handlers/exception.py", line 34, in inner
    response = get_response(request)
  File "/opt/netbox/venv/lib/python3.7/site-packages/django/core/handlers/base.py", line 115, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "/opt/netbox/venv/lib/python3.7/site-packages/django/core/handlers/base.py", line 113, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/opt/netbox/venv/lib/python3.7/site-packages/django/views/decorators/csrf.py", line 54, in wrapped_view
    return view_func(*args, **kwargs)
  File "/opt/netbox/venv/lib/python3.7/site-packages/rest_framework/viewsets.py", line 114, in view
    return self.dispatch(request, *args, **kwargs)
  File "/opt/netbox/netbox/utilities/api.py", line 330, in dispatch
    return super().dispatch(request, *args, **kwargs)
  File "/opt/netbox/venv/lib/python3.7/site-packages/rest_framework/views.py", line 505, in dispatch
    response = self.handle_exception(exc)
  File "/opt/netbox/venv/lib/python3.7/site-packages/rest_framework/views.py", line 465, in handle_exception
    self.raise_uncaught_exception(exc)
  File "/opt/netbox/venv/lib/python3.7/site-packages/rest_framework/views.py", line 476, in raise_uncaught_exception
    raise exc
  File "/opt/netbox/venv/lib/python3.7/site-packages/rest_framework/views.py", line 502, in dispatch
    response = handler(request, *args, **kwargs)
  File "/opt/netbox/venv/lib/python3.7/site-packages/rest_framework/mixins.py", line 18, in create
    serializer.is_valid(raise_exception=True)
  File "/opt/netbox/venv/lib/python3.7/site-packages/rest_framework/serializers.py", line 234, in is_valid
    self._validated_data = self.run_validation(self.initial_data)
  File "/opt/netbox/venv/lib/python3.7/site-packages/rest_framework/serializers.py", line 436, in run_validation
    value = self.validate(value)
  File "/opt/netbox/netbox/ipam/api/serializers.py", line 125, in validate
    validator.set_context(self)

Exception Type: AttributeError at /api/ipam/vlans/
Exception Value: 'UniqueTogetherValidator' object has no attribute 'set_context'

[Links2004]

this may is related to
encode/django-rest-framework#7062
and
encode/django-rest-framework#6172

set_context where dropped in the django-rest-framework with version 3.11

[DouglasHeriot]

I've just run into this as well, in the automated tests on netbox-community/ansible_modules#155

I can see this change was made in 613e378

The Django REST release notes seem to say this was simply deprecated and not removed, but the pull requests linked above seem otherwise.
https://www.django-rest-framework.org/community/3.11-announcement/#validator-default-context

[jeremystretch]

The root change in DRF 3.11 was addressed in a914a7c, however a handful of serializers with their own unique calls to set_context() were missed.

[kr3ator]

When will this fix be available in the master and netbox-docker?