Closes #19924: Record model features on ObjectType (#19939)

* Convert ObjectType to a concrete child model of ContentType

* Add public flag to ObjectType

* Catch post_migrate signal to update ObjectTypes

* Reference ObjectType records instead of registry for feature support

* Automatically create ObjectTypes

* Introduce has_feature() utility function

* ObjectTypeManager should not inherit from ContentTypeManager

* Misc cleanup

* Don't populate ObjectTypes during migration

* Don't automatically create ObjectTypes when a ContentType is created

* Fix test

* Extend has_feature() to accept a model or OT/CT

* Misc cleanup

* Deprecate get_for_id() on ObjectTypeManager

* Rename contenttypes.py to object_types.py

* Add index to features ArrayField

* Keep FK & M2M fields pointing to ContentType

* Add get_for_models() to ObjectTypeManager

* Add tests for manager methods & utility functions

* Fix migrations for M2M relations to ObjectType

* model_is_public() should return False for non-core & non-plugin models

* Order ObjectType by app_label & model name

* Resolve migrations conflict

netbox/core/migrations/0008_contenttype_proxy.py

@@ -1,4 +1,4 @@
-import core.models.contenttypes
+import core.models.object_types
 from django.db import migrations
 
 
@@ -19,7 +19,7 @@ class Migration(migrations.Migration):
             },
             bases=('contenttypes.contenttype',),
             managers=[
-                ('objects', core.models.contenttypes.ObjectTypeManager()),
+                ('objects', core.models.object_types.ObjectTypeManager()),
             ],
         ),
     ]

netbox/core/migrations/0018_concrete_objecttype.py

@@ -0,0 +1,63 @@
+import django.contrib.postgres.fields
+import django.contrib.postgres.indexes
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('contenttypes', '0002_remove_content_type_name'),
+        ('core', '0017_objectchange_message'),
+    ]
+
+    operations = [
+        # Delete the proxy model from the migration state
+        migrations.DeleteModel(
+            name='ObjectType',
+        ),
+        # Create the new concrete model
+        migrations.CreateModel(
+            name='ObjectType',
+            fields=[
+                (
+                    'contenttype_ptr',
+                    models.OneToOneField(
+                        on_delete=django.db.models.deletion.CASCADE,
+                        parent_link=True,
+                        primary_key=True,
+                        serialize=False,
+                        to='contenttypes.contenttype',
+                        related_name='object_type'
+                    )
+                ),
+                (
+                    'public',
+                    models.BooleanField(
+                        default=False
+                    )
+                ),
+                (
+                    'features',
+                    django.contrib.postgres.fields.ArrayField(
+                        base_field=models.CharField(max_length=50),
+                        default=list,
+                        size=None
+                    )
+                ),
+            ],
+            options={
+                'verbose_name': 'object type',
+                'verbose_name_plural': 'object types',
+                'ordering': ('app_label', 'model'),
+                'indexes': [
+                    django.contrib.postgres.indexes.GinIndex(
+                        fields=['features'],
+                        name='core_object_feature_aec4de_gin'
+                    ),
+                ]
+            },
+            bases=('contenttypes.contenttype',),
+            managers=[],
+        ),
+    ]

netbox/core/models/__init__.py

@@ -1,4 +1,4 @@
-from .contenttypes import *
+from .object_types import *
 from .change_logging import *
 from .config import *
 from .data import *

netbox/core/models/change_logging.py

@@ -11,8 +11,8 @@ from mptt.models import MPTTModel
 from core.choices import ObjectChangeActionChoices
 from core.querysets import ObjectChangeQuerySet
 from netbox.models.features import ChangeLoggingMixin
+from netbox.models.features import has_feature
 from utilities.data import shallow_compare_dict
-from .contenttypes import ObjectType
 
 __all__ = (
     'ObjectChange',
@@ -124,7 +124,7 @@ class ObjectChange(models.Model):
         super().clean()
 
         # Validate the assigned object type
-        if self.changed_object_type not in ObjectType.objects.with_feature('change_logging'):
+        if not has_feature(self.changed_object_type, 'change_logging'):
             raise ValidationError(
                 _("Change logging is not supported for this object type ({type}).").format(
                     type=self.changed_object_type

netbox/core/models/contenttypes.py

@@ -1,78 +1,3 @@
-from django.contrib.contenttypes.models import ContentType, ContentTypeManager
-from django.db.models import Q
-
-from netbox.plugins import PluginConfig
-from netbox.registry import registry
-from utilities.string import title
-
-__all__ = (
-    'ObjectType',
-    'ObjectTypeManager',
-)
-
-
-class ObjectTypeManager(ContentTypeManager):
-
-    def public(self):
-        """
-        Filter the base queryset to return only ContentTypes corresponding to "public" models; those which are listed
-        in registry['models'] and intended for reference by other objects.
-        """
-        q = Q()
-        for app_label, models in registry['models'].items():
-            q |= Q(app_label=app_label, model__in=models)
-        return self.get_queryset().filter(q)
-
-    def with_feature(self, feature):
-        """
-        Return the ContentTypes only for models which are registered as supporting the specified feature. For example,
-        we can find all ContentTypes for models which support webhooks with
-
-            ContentType.objects.with_feature('event_rules')
-        """
-        if feature not in registry['model_features']:
-            raise KeyError(
-                f"{feature} is not a registered model feature! Valid features are: {registry['model_features'].keys()}"
-            )
-
-        q = Q()
-        for app_label, models in registry['model_features'][feature].items():
-            q |= Q(app_label=app_label, model__in=models)
-
-        return self.get_queryset().filter(q)
-
-
-class ObjectType(ContentType):
-    """
-    Wrap Django's native ContentType model to use our custom manager.
-    """
-    objects = ObjectTypeManager()
-
-    class Meta:
-        proxy = True
-
-    @property
-    def app_labeled_name(self):
-        # Override ContentType's "app | model" representation style.
-        return f"{self.app_verbose_name} > {title(self.model_verbose_name)}"
-
-    @property
-    def app_verbose_name(self):
-        if model := self.model_class():
-            return model._meta.app_config.verbose_name
-
-    @property
-    def model_verbose_name(self):
-        if model := self.model_class():
-            return model._meta.verbose_name
-
-    @property
-    def model_verbose_name_plural(self):
-        if model := self.model_class():
-            return model._meta.verbose_name_plural
-
-    @property
-    def is_plugin_model(self):
-        if not (model := self.model_class()):
-            return  # Return null if model class is invalid
-        return isinstance(model._meta.app_config, PluginConfig)
+# TODO: Remove this module in NetBox v4.5
+# Provided for backward compatibility
+from .object_types import *

netbox/core/models/jobs.py

@@ -20,6 +20,7 @@ from core.choices import JobStatusChoices
 from core.dataclasses import JobLogEntry
 from core.models import ObjectType
 from core.signals import job_end, job_start
+from netbox.models.features import has_feature
 from utilities.json import JobLogDecoder
 from utilities.querysets import RestrictedQuerySet
 from utilities.rqworker import get_queue_for_model
@@ -148,7 +149,7 @@ class Job(models.Model):
         super().clean()
 
         # Validate the assigned object type
-        if self.object_type and self.object_type not in ObjectType.objects.with_feature('jobs'):
+        if self.object_type and not has_feature(self.object_type, 'jobs'):
             raise ValidationError(
                 _("Jobs cannot be assigned to this object type ({type}).").format(type=self.object_type)
             )

netbox/core/models/object_types.py

@@ -0,0 +1,205 @@
+from collections import defaultdict
+
+from django.contrib.contenttypes.models import ContentType
+from django.contrib.postgres.fields import ArrayField
+from django.contrib.postgres.indexes import GinIndex
+from django.core.exceptions import ObjectDoesNotExist
+from django.db import models
+from django.db.models import Q
+from django.utils.translation import gettext as _
+
+from netbox.plugins import PluginConfig
+from netbox.registry import registry
+from utilities.string import title
+
+__all__ = (
+    'ObjectType',
+    'ObjectTypeManager',
+    'ObjectTypeQuerySet',
+)
+
+
+class ObjectTypeQuerySet(models.QuerySet):
+
+    def create(self, **kwargs):
+        # If attempting to create a new ObjectType for a given app_label & model, replace those kwargs
+        # with a reference to the ContentType (if one exists).
+        if (app_label := kwargs.get('app_label')) and (model := kwargs.get('model')):
+            try:
+                kwargs['contenttype_ptr'] = ContentType.objects.get(app_label=app_label, model=model)
+            except ObjectDoesNotExist:
+                pass
+        return super().create(**kwargs)
+
+
+class ObjectTypeManager(models.Manager):
+
+    def get_queryset(self):
+        return ObjectTypeQuerySet(self.model, using=self._db)
+
+    def get_by_natural_key(self, app_label, model):
+        """
+        Retrieve an ObjectType by its application label & model name.
+
+        This method exists to provide parity with ContentTypeManager.
+        """
+        return self.get(app_label=app_label, model=model)
+
+    # TODO: Remove in NetBox v4.5
+    def get_for_id(self, id):
+        """
+        Retrieve an ObjectType by its primary key (numeric ID).
+
+        This method exists to provide parity with ContentTypeManager.
+        """
+        return self.get(pk=id)
+
+    def _get_opts(self, model, for_concrete_model):
+        if for_concrete_model:
+            model = model._meta.concrete_model
+        return model._meta
+
+    def get_for_model(self, model, for_concrete_model=True):
+        """
+        Retrieve or create and return the ObjectType for a model.
+        """
+        from netbox.models.features import get_model_features, model_is_public
+        opts = self._get_opts(model, for_concrete_model)
+
+        try:
+            # Use .get() instead of .get_or_create() initially to ensure db_for_read is honored (Django bug #20401).
+            ot = self.get(app_label=opts.app_label, model=opts.model_name)
+        except self.model.DoesNotExist:
+            # If the ObjectType doesn't exist, create it. (Use .get_or_create() to avoid race conditions.)
+            ot = self.get_or_create(
+                app_label=opts.app_label,
+                model=opts.model_name,
+                public=model_is_public(model),
+                features=get_model_features(model.__class__),
+            )[0]
+
+        return ot
+
+    def get_for_models(self, *models, for_concrete_models=True):
+        """
+        Retrieve or create the ObjectTypes for multiple models, returning a mapping {model: ObjectType}.
+
+        This method exists to provide parity with ContentTypeManager.
+        """
+        from netbox.models.features import get_model_features, model_is_public
+        results = {}
+
+        # Compile the model and options mappings
+        needed_models = defaultdict(set)
+        needed_opts = defaultdict(list)
+        for model in models:
+            opts = self._get_opts(model, for_concrete_models)
+            needed_models[opts.app_label].add(opts.model_name)
+            needed_opts[(opts.app_label, opts.model_name)].append(model)
+
+        # Fetch existing ObjectType from the database
+        condition = Q(
+            *(
+                Q(('app_label', app_label), ('model__in', model_names))
+                for app_label, model_names in needed_models.items()
+            ),
+            _connector=Q.OR,
+        )
+        for ot in self.filter(condition):
+            opts_models = needed_opts.pop((ot.app_label, ot.model), [])
+            for model in opts_models:
+                results[model] = ot
+
+        # Create any missing ObjectTypes
+        for (app_label, model_name), opts_models in needed_opts.items():
+            for model in opts_models:
+                results[model] = self.create(
+                    app_label=app_label,
+                    model=model_name,
+                    public=model_is_public(model),
+                    features=get_model_features(model.__class__),
+                )
+
+        return results
+
+    def public(self):
+        """
+        Includes only ObjectTypes for "public" models.
+
+        Filter the base queryset to return only ObjectTypes corresponding to public models; those which are intended
+        for reference by other objects within the application.
+        """
+        return self.get_queryset().filter(public=True)
+
+    def with_feature(self, feature):
+        """
+        Return ObjectTypes only for models which support the given feature.
+
+        Only ObjectTypes which list the specified feature will be included. Supported features are declared in
+        netbox.models.features.FEATURES_MAP. For example, we can find all ObjectTypes for models which support event
+        rules with:
+
+            ObjectType.objects.with_feature('event_rules')
+        """
+        if feature not in registry['model_features']:
+            raise KeyError(
+                f"{feature} is not a registered model feature! Valid features are: {registry['model_features'].keys()}"
+            )
+        return self.get_queryset().filter(features__contains=[feature])
+
+
+class ObjectType(ContentType):
+    """
+    Wrap Django's native ContentType model to use our custom manager.
+    """
+    contenttype_ptr = models.OneToOneField(
+        on_delete=models.CASCADE,
+        to='contenttypes.ContentType',
+        parent_link=True,
+        primary_key=True,
+        serialize=False,
+        related_name='object_type',
+    )
+    public = models.BooleanField(
+        default=False,
+    )
+    features = ArrayField(
+        base_field=models.CharField(max_length=50),
+        default=list,
+    )
+
+    objects = ObjectTypeManager()
+
+    class Meta:
+        verbose_name = _('object type')
+        verbose_name_plural = _('object types')
+        ordering = ('app_label', 'model')
+        indexes = [
+            GinIndex(fields=['features']),
+        ]
+
+    @property
+    def app_labeled_name(self):
+        # Override ContentType's "app | model" representation style.
+        return f"{self.app_verbose_name} > {title(self.model_verbose_name)}"
+
+    @property
+    def app_verbose_name(self):
+        if model := self.model_class():
+            return model._meta.app_config.verbose_name
+
+    @property
+    def model_verbose_name(self):
+        if model := self.model_class():
+            return model._meta.verbose_name
+
+    @property
+    def model_verbose_name_plural(self):
+        if model := self.model_class():
+            return model._meta.verbose_name_plural
+
+    @property
+    def is_plugin_model(self):
+        if not (model := self.model_class()):
+            return  # Return null if model class is invalid
+        return isinstance(model._meta.app_config, PluginConfig)

netbox/core/signals.py

@@ -2,9 +2,9 @@ import logging
 from threading import local
 
 from django.contrib.contenttypes.models import ContentType
-from django.core.exceptions import ValidationError
+from django.core.exceptions import ObjectDoesNotExist, ValidationError
 from django.db.models.fields.reverse_related import ManyToManyRel, ManyToOneRel
-from django.db.models.signals import m2m_changed, post_save, pre_delete
+from django.db.models.signals import m2m_changed, post_migrate, post_save, pre_delete
 from django.dispatch import receiver, Signal
 from django.core.signals import request_finished
 from django.utils.translation import gettext_lazy as _
@@ -12,11 +12,12 @@ from django_prometheus.models import model_deletes, model_inserts, model_updates
 
 from core.choices import JobStatusChoices, ObjectChangeActionChoices
 from core.events import *
+from core.models import ObjectType
 from extras.events import enqueue_event
 from extras.utils import run_validators
 from netbox.config import get_config
 from netbox.context import current_request, events_queue
-from netbox.models.features import ChangeLoggingMixin
+from netbox.models.features import ChangeLoggingMixin, get_model_features, model_is_public
 from utilities.exceptions import AbortRequest
 from .models import ConfigRevision, DataSource, ObjectChange
 
@@ -40,6 +41,37 @@ post_sync = Signal()
 clear_events = Signal()
 
 
+#
+# Object types
+#
+
+@receiver(post_migrate)
+def update_object_types(sender, **kwargs):
+    """
+    Create or update the corresponding ObjectType for each model within the migrated app.
+    """
+    for model in sender.get_models():
+        app_label, model_name = model._meta.label_lower.split('.')
+
+        # Determine whether model is public and its supported features
+        is_public = model_is_public(model)
+        features = get_model_features(model)
+
+        # Create/update the ObjectType for the model
+        try:
+            ot = ObjectType.objects.get_by_natural_key(app_label=app_label, model=model_name)
+            ot.public = is_public
+            ot.features = features
+            ot.save()
+        except ObjectDoesNotExist:
+            ObjectType.objects.create(
+                app_label=app_label,
+                model=model_name,
+                public=is_public,
+                features=features,
+            )
+
+
 #
 # Change logging & event handling
 #

netbox/core/tests/test_models.py

@@ -1,7 +1,10 @@
+from django.contrib.contenttypes.models import ContentType
+from django.core.exceptions import ObjectDoesNotExist
 from django.test import TestCase
 
-from core.models import DataSource
+from core.models import DataSource, ObjectType
 from core.choices import ObjectChangeActionChoices
+from dcim.models import Site, Location, Device
 from netbox.constants import CENSOR_TOKEN, CENSOR_TOKEN_CHANGED
 
 
@@ -120,3 +123,80 @@ class DataSourceChangeLoggingTestCase(TestCase):
         self.assertEqual(objectchange.prechange_data['parameters']['password'], CENSOR_TOKEN)
         self.assertEqual(objectchange.postchange_data['parameters']['username'], 'username2')
         self.assertEqual(objectchange.postchange_data['parameters']['password'], CENSOR_TOKEN)
+
+
+class ObjectTypeTest(TestCase):
+
+    def test_create(self):
+        """
+        Test that an ObjectType created for a given app_label & model name will be automatically assigned to
+        the appropriate ContentType.
+        """
+        kwargs = {
+            'app_label': 'foo',
+            'model': 'bar',
+        }
+        ct = ContentType.objects.create(**kwargs)
+        ot = ObjectType.objects.create(**kwargs)
+        self.assertEqual(ot.contenttype_ptr, ct)
+
+    def test_get_by_natural_key(self):
+        """
+        Test that get_by_natural_key() returns the appropriate ObjectType.
+        """
+        self.assertEqual(
+            ObjectType.objects.get_by_natural_key('dcim', 'site'),
+            ObjectType.objects.get(app_label='dcim', model='site')
+        )
+        with self.assertRaises(ObjectDoesNotExist):
+            ObjectType.objects.get_by_natural_key('foo', 'bar')
+
+    def test_get_for_id(self):
+        """
+        Test that get_by_id() returns the appropriate ObjectType.
+        """
+        ot = ObjectType.objects.get_by_natural_key('dcim', 'site')
+        self.assertEqual(
+            ObjectType.objects.get_for_id(ot.pk),
+            ObjectType.objects.get(pk=ot.pk)
+        )
+        with self.assertRaises(ObjectDoesNotExist):
+            ObjectType.objects.get_for_id(0)
+
+    def test_get_for_model(self):
+        """
+        Test that get_by_model() returns the appropriate ObjectType.
+        """
+        self.assertEqual(
+            ObjectType.objects.get_for_model(Site),
+            ObjectType.objects.get_by_natural_key('dcim', 'site')
+        )
+
+    def test_get_for_models(self):
+        """
+        Test that get_by_models() returns the appropriate ObjectType mapping.
+        """
+        self.assertEqual(
+            ObjectType.objects.get_for_models(Site, Location, Device),
+            {
+                Site: ObjectType.objects.get_by_natural_key('dcim', 'site'),
+                Location: ObjectType.objects.get_by_natural_key('dcim', 'location'),
+                Device: ObjectType.objects.get_by_natural_key('dcim', 'device'),
+            }
+        )
+
+    def test_public(self):
+        """
+        Test that public() returns only ObjectTypes for public models.
+        """
+        public_ots = ObjectType.objects.public()
+        self.assertIn(ObjectType.objects.get_by_natural_key('dcim', 'site'), public_ots)
+        self.assertNotIn(ObjectType.objects.get_by_natural_key('extras', 'taggeditem'), public_ots)
+
+    def test_with_feature(self):
+        """
+        Test that with_feature() returns only ObjectTypes for models which support the specified feature.
+        """
+        bookmarks_ots = ObjectType.objects.with_feature('bookmarks')
+        self.assertIn(ObjectType.objects.get_by_natural_key('dcim', 'site'), bookmarks_ots)
+        self.assertNotIn(ObjectType.objects.get_by_natural_key('dcim', 'cabletermination'), bookmarks_ots)

netbox/dcim/models/cables.py

@@ -1,6 +1,7 @@
 import itertools
 
 from django.contrib.contenttypes.fields import GenericForeignKey
+from django.contrib.contenttypes.models import ContentType
 from django.core.exceptions import ValidationError
 from django.db import models
 from django.dispatch import Signal
@@ -479,13 +480,13 @@ class CablePath(models.Model):
     def origin_type(self):
         if self.path:
             ct_id, _ = decompile_path_node(self.path[0][0])
-            return ObjectType.objects.get_for_id(ct_id)
+            return ContentType.objects.get_for_id(ct_id)
 
     @property
     def destination_type(self):
         if self.is_complete:
             ct_id, _ = decompile_path_node(self.path[-1][0])
-            return ObjectType.objects.get_for_id(ct_id)
+            return ContentType.objects.get_for_id(ct_id)
 
     @property
     def _path_decompiled(self):

netbox/dcim/models/devices.py

@@ -4,6 +4,7 @@ import yaml
 from functools import cached_property
 
 from django.contrib.contenttypes.fields import GenericForeignKey, GenericRelation
+from django.contrib.contenttypes.models import ContentType
 from django.core.exceptions import ValidationError
 from django.core.files.storage import default_storage
 from django.core.validators import MaxValueValidator, MinValueValidator
@@ -15,7 +16,6 @@ from django.urls import reverse
 from django.utils.safestring import mark_safe
 from django.utils.translation import gettext_lazy as _
 
-from core.models import ObjectType
 from dcim.choices import *
 from dcim.constants import *
 from dcim.fields import MACAddressField
@@ -1328,7 +1328,7 @@ class MACAddress(PrimaryModel):
         super().clean()
         if self._original_assigned_object_id and self._original_assigned_object_type_id:
             assigned_object = self.assigned_object
-            ct = ObjectType.objects.get_for_id(self._original_assigned_object_type_id)
+            ct = ContentType.objects.get_for_id(self._original_assigned_object_type_id)
             original_assigned_object = ct.get_object_for_this_type(pk=self._original_assigned_object_id)
 
             if (

netbox/extras/events.py

@@ -11,7 +11,7 @@ from django_rq import get_queue
 from core.events import *
 from netbox.config import get_config
 from netbox.constants import RQ_QUEUE_DEFAULT
-from netbox.registry import registry
+from netbox.models.features import has_feature
 from users.models import User
 from utilities.api import get_serializer_for_model
 from utilities.rqworker import get_rq_retry
@@ -55,11 +55,12 @@ def enqueue_event(queue, instance, user, request_id, event_type):
     Enqueue a serialized representation of a created/updated/deleted object for the processing of
     events once the request has completed.
     """
-    # Determine whether this type of object supports event rules
+    # Bail if this type of object does not support event rules
+    if not has_feature(instance, 'event_rules'):
+        return
+
     app_label = instance._meta.app_label
     model_name = instance._meta.model_name
-    if model_name not in registry['model_features']['event_rules'].get(app_label, []):
-        return
 
     assert instance.pk is not None
     key = f'{app_label}.{model_name}:{instance.pk}'

netbox/extras/migrations/0111_rename_content_types.py

@@ -24,7 +24,7 @@ class Migration(migrations.Migration):
             model_name='customfield',
             name='object_type',
             field=models.ForeignKey(
-                blank=True, null=True, on_delete=django.db.models.deletion.PROTECT, to='core.objecttype'
+                blank=True, null=True, on_delete=django.db.models.deletion.PROTECT, to='contenttypes.contenttype'
             ),
         ),
         migrations.RunSQL((

netbox/extras/migrations/0128_tableconfig.py

@@ -37,7 +37,9 @@ class Migration(migrations.Migration):
                 (
                     'object_type',
                     models.ForeignKey(
-                        on_delete=django.db.models.deletion.CASCADE, related_name='table_configs', to='core.objecttype'
+                        on_delete=django.db.models.deletion.CASCADE,
+                        related_name='table_configs',
+                        to='contenttypes.contenttype'
                     ),
                 ),
                 (

netbox/extras/migrations/0131_concrete_objecttype.py

@@ -0,0 +1,42 @@
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('contenttypes', '0002_remove_content_type_name'),
+        ('extras', '0130_imageattachment_description'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='customfield',
+            name='object_types',
+            field=models.ManyToManyField(related_name='custom_fields', to='contenttypes.contenttype'),
+        ),
+        migrations.AlterField(
+            model_name='customlink',
+            name='object_types',
+            field=models.ManyToManyField(related_name='custom_links', to='contenttypes.contenttype'),
+        ),
+        migrations.AlterField(
+            model_name='eventrule',
+            name='object_types',
+            field=models.ManyToManyField(related_name='event_rules', to='contenttypes.contenttype'),
+        ),
+        migrations.AlterField(
+            model_name='exporttemplate',
+            name='object_types',
+            field=models.ManyToManyField(related_name='export_templates', to='contenttypes.contenttype'),
+        ),
+        migrations.AlterField(
+            model_name='savedfilter',
+            name='object_types',
+            field=models.ManyToManyField(related_name='saved_filters', to='contenttypes.contenttype'),
+        ),
+        migrations.AlterField(
+            model_name='tag',
+            name='object_types',
+            field=models.ManyToManyField(blank=True, related_name='+', to='contenttypes.contenttype'),
+        ),
+    ]

netbox/extras/models/configs.py

@@ -1,15 +1,16 @@
-from django.apps import apps
+from collections import defaultdict
+
 from django.conf import settings
 from django.core.validators import ValidationError
 from django.db import models
 from django.urls import reverse
 from django.utils.translation import gettext_lazy as _
 
+from core.models import ObjectType
 from extras.models.mixins import RenderTemplateMixin
 from extras.querysets import ConfigContextQuerySet
 from netbox.models import ChangeLoggedModel
 from netbox.models.features import CloningMixin, CustomLinksMixin, ExportTemplatesMixin, SyncedDataMixin, TagsMixin
-from netbox.registry import registry
 from utilities.data import deepmerge
 
 __all__ = (
@@ -239,15 +240,12 @@ class ConfigTemplate(
     sync_data.alters_data = True
 
     def get_context(self, context=None, queryset=None):
-        _context = dict()
-        for app, model_names in registry['models'].items():
-            _context.setdefault(app, {})
-            for model_name in model_names:
-                try:
-                    model = apps.get_registered_model(app, model_name)
-                    _context[app][model.__name__] = model
-                except LookupError:
-                    pass
+        _context = defaultdict(dict)
+
+        # Populate all public models for reference within the template
+        for object_type in ObjectType.objects.public():
+            if model := object_type.model_class():
+                _context[object_type.app_label][model.__name__] = model
 
         # Apply the provided context data, if any
         if context is not None:

netbox/extras/models/customfields.py

@@ -72,7 +72,7 @@ class CustomFieldManager(models.Manager.from_queryset(RestrictedQuerySet)):
 
 class CustomField(CloningMixin, ExportTemplatesMixin, ChangeLoggedModel):
     object_types = models.ManyToManyField(
-        to='core.ObjectType',
+        to='contenttypes.ContentType',
         related_name='custom_fields',
         help_text=_('The object(s) to which this field applies.')
     )
@@ -84,7 +84,7 @@ class CustomField(CloningMixin, ExportTemplatesMixin, ChangeLoggedModel):
         help_text=_('The type of data this custom field holds')
     )
     related_object_type = models.ForeignKey(
-        to='core.ObjectType',
+        to='contenttypes.ContentType',
         on_delete=models.PROTECT,
         blank=True,
         null=True,

netbox/extras/models/models.py

@@ -12,17 +12,16 @@ from django.utils import timezone
 from django.utils.translation import gettext_lazy as _
 from rest_framework.utils.encoders import JSONEncoder
 
-from core.models import ObjectType
 from extras.choices import *
 from extras.conditions import ConditionSet, InvalidCondition
 from extras.constants import *
-from extras.utils import image_upload
 from extras.models.mixins import RenderTemplateMixin
+from extras.utils import image_upload
 from netbox.config import get_config
 from netbox.events import get_event_type_choices
 from netbox.models import ChangeLoggedModel
 from netbox.models.features import (
-    CloningMixin, CustomFieldsMixin, CustomLinksMixin, ExportTemplatesMixin, SyncedDataMixin, TagsMixin
+    CloningMixin, CustomFieldsMixin, CustomLinksMixin, ExportTemplatesMixin, SyncedDataMixin, TagsMixin, has_feature
 )
 from utilities.html import clean_html
 from utilities.jinja2 import render_jinja2
@@ -50,7 +49,7 @@ class EventRule(CustomFieldsMixin, ExportTemplatesMixin, TagsMixin, ChangeLogged
     webhook or executing a custom script.
     """
     object_types = models.ManyToManyField(
-        to='core.ObjectType',
+        to='contenttypes.ContentType',
         related_name='event_rules',
         verbose_name=_('object types'),
         help_text=_("The object(s) to which this rule applies.")
@@ -299,7 +298,7 @@ class CustomLink(CloningMixin, ExportTemplatesMixin, ChangeLoggedModel):
     code to be rendered with an object as context.
     """
     object_types = models.ManyToManyField(
-        to='core.ObjectType',
+        to='contenttypes.ContentType',
         related_name='custom_links',
         help_text=_('The object type(s) to which this link applies.')
     )
@@ -395,7 +394,7 @@ class CustomLink(CloningMixin, ExportTemplatesMixin, ChangeLoggedModel):
 
 class ExportTemplate(SyncedDataMixin, CloningMixin, ExportTemplatesMixin, ChangeLoggedModel, RenderTemplateMixin):
     object_types = models.ManyToManyField(
-        to='core.ObjectType',
+        to='contenttypes.ContentType',
         related_name='export_templates',
         help_text=_('The object type(s) to which this template applies.')
     )
@@ -460,7 +459,7 @@ class SavedFilter(CloningMixin, ExportTemplatesMixin, ChangeLoggedModel):
     A set of predefined keyword parameters that can be reused to filter for specific objects.
     """
     object_types = models.ManyToManyField(
-        to='core.ObjectType',
+        to='contenttypes.ContentType',
         related_name='saved_filters',
         help_text=_('The object type(s) to which this filter applies.')
     )
@@ -540,7 +539,7 @@ class TableConfig(CloningMixin, ChangeLoggedModel):
     A saved configuration of columns and ordering which applies to a specific table.
     """
     object_type = models.ForeignKey(
-        to='core.ObjectType',
+        to='contenttypes.ContentType',
         on_delete=models.CASCADE,
         related_name='table_configs',
         help_text=_("The table's object type"),
@@ -707,7 +706,7 @@ class ImageAttachment(ChangeLoggedModel):
         super().clean()
 
         # Validate the assigned object type
-        if self.object_type not in ObjectType.objects.with_feature('image_attachments'):
+        if not has_feature(self.object_type, 'image_attachments'):
             raise ValidationError(
                 _("Image attachments cannot be assigned to this object type ({type}).").format(type=self.object_type)
             )
@@ -807,7 +806,7 @@ class JournalEntry(CustomFieldsMixin, CustomLinksMixin, TagsMixin, ExportTemplat
         super().clean()
 
         # Validate the assigned object type
-        if self.assigned_object_type not in ObjectType.objects.with_feature('journaling'):
+        if not has_feature(self.assigned_object_type, 'journaling'):
             raise ValidationError(
                 _("Journaling is not supported for this object type ({type}).").format(type=self.assigned_object_type)
             )
@@ -863,7 +862,7 @@ class Bookmark(models.Model):
         super().clean()
 
         # Validate the assigned object type
-        if self.object_type not in ObjectType.objects.with_feature('bookmarks'):
+        if not has_feature(self.object_type, 'bookmarks'):
             raise ValidationError(
                 _("Bookmarks cannot be assigned to this object type ({type}).").format(type=self.object_type)
             )

netbox/extras/models/notifications.py

@@ -7,9 +7,9 @@ from django.db import models
 from django.urls import reverse
 from django.utils.translation import gettext_lazy as _
 
-from core.models import ObjectType
 from extras.querysets import NotificationQuerySet
 from netbox.models import ChangeLoggedModel
+from netbox.models.features import has_feature
 from netbox.registry import registry
 from users.models import User
 from utilities.querysets import RestrictedQuerySet
@@ -94,7 +94,7 @@ class Notification(models.Model):
         super().clean()
 
         # Validate the assigned object type
-        if self.object_type not in ObjectType.objects.with_feature('notifications'):
+        if not has_feature(self.object_type, 'notifications'):
             raise ValidationError(
                 _("Objects of this type ({type}) do not support notifications.").format(type=self.object_type)
             )
@@ -235,7 +235,7 @@ class Subscription(models.Model):
         super().clean()
 
         # Validate the assigned object type
-        if self.object_type not in ObjectType.objects.with_feature('notifications'):
+        if not has_feature(self.object_type, 'notifications'):
             raise ValidationError(
                 _("Objects of this type ({type}) do not support notifications.").format(type=self.object_type)
             )

netbox/extras/models/tags.py

@@ -35,7 +35,7 @@ class Tag(CloningMixin, ExportTemplatesMixin, ChangeLoggedModel, TagBase):
         blank=True,
     )
     object_types = models.ManyToManyField(
-        to='core.ObjectType',
+        to='contenttypes.ContentType',
         related_name='+',
         blank=True,
         help_text=_("The object type(s) to which this tag can be applied.")

netbox/extras/signals.py

@@ -3,12 +3,11 @@ from django.db.models.signals import m2m_changed, post_save, pre_delete
 from django.dispatch import receiver
 
 from core.events import *
-from core.models import ObjectType
 from core.signals import job_end, job_start
 from extras.events import process_event_rules
 from extras.models import EventRule, Notification, Subscription
 from netbox.config import get_config
-from netbox.registry import registry
+from netbox.models.features import has_feature
 from netbox.signals import post_clean
 from utilities.exceptions import AbortRequest
 from .models import CustomField, TaggedItem
@@ -82,7 +81,7 @@ def validate_assigned_tags(sender, instance, action, model, pk_set, **kwargs):
     """
     if action != 'pre_add':
         return
-    ct = ObjectType.objects.get_for_model(instance)
+    ct = ContentType.objects.get_for_model(instance)
     # Retrieve any applied Tags that are restricted to certain object types
     for tag in model.objects.filter(pk__in=pk_set, object_types__isnull=False).prefetch_related('object_types'):
         if ct not in tag.object_types.all():
@@ -150,17 +149,25 @@ def notify_object_changed(sender, instance, **kwargs):
         event_type = OBJECT_DELETED
 
     # Skip unsupported object types
-    ct = ContentType.objects.get_for_model(instance)
-    if ct.model not in registry['model_features']['notifications'].get(ct.app_label, []):
+    if not has_feature(instance, 'notifications'):
         return
 
+    ct = ContentType.objects.get_for_model(instance)
+
     # Find all subscribed Users
-    subscribed_users = Subscription.objects.filter(object_type=ct, object_id=instance.pk).values_list('user', flat=True)
+    subscribed_users = Subscription.objects.filter(
+        object_type=ct,
+        object_id=instance.pk
+    ).values_list('user', flat=True)
     if not subscribed_users:
         return
 
     # Delete any existing Notifications for the object
-    Notification.objects.filter(object_type=ct, object_id=instance.pk, user__in=subscribed_users).delete()
+    Notification.objects.filter(
+        object_type=ct,
+        object_id=instance.pk,
+        user__in=subscribed_users
+    ).delete()
 
     # Create Notifications for Subscribers
     Notification.objects.bulk_create([

netbox/ipam/models/ip.py

@@ -1,5 +1,6 @@
 import netaddr
 from django.contrib.contenttypes.fields import GenericForeignKey
+from django.contrib.contenttypes.models import ContentType
 from django.core.exceptions import ValidationError
 from django.db import models
 from django.db.models import F
@@ -7,7 +8,6 @@ from django.db.models.functions import Cast
 from django.utils.functional import cached_property
 from django.utils.translation import gettext_lazy as _
 
-from core.models import ObjectType
 from dcim.models.mixins import CachedScopeMixin
 from ipam.choices import *
 from ipam.constants import *
@@ -917,7 +917,7 @@ class IPAddress(ContactsMixin, PrimaryModel):
 
         if self._original_assigned_object_id and self._original_assigned_object_type_id:
             parent = getattr(self.assigned_object, 'parent_object', None)
-            ct = ObjectType.objects.get_for_id(self._original_assigned_object_type_id)
+            ct = ContentType.objects.get_for_id(self._original_assigned_object_type_id)
             original_assigned_object = ct.get_object_for_this_type(pk=self._original_assigned_object_id)
             original_parent = getattr(original_assigned_object, 'parent_object', None)
 

netbox/netbox/constants.py

@@ -1,3 +1,18 @@
+CORE_APPS = (
+    'account',
+    'circuits',
+    'core',
+    'dcim',
+    'extras',
+    'ipam',
+    'tenancy',
+    'users',
+    'utilities',
+    'virtualization',
+    'vpn',
+    'wireless',
+)
+
 # RQ queue names
 RQ_QUEUE_DEFAULT = 'default'
 RQ_QUEUE_HIGH = 'high'

netbox/netbox/models/features.py

@@ -3,6 +3,7 @@ from collections import defaultdict
 from functools import cached_property
 
 from django.contrib.contenttypes.fields import GenericRelation
+from django.contrib.contenttypes.models import ContentType
 from django.core.validators import ValidationError
 from django.db import models
 from django.db.models import Q
@@ -16,7 +17,9 @@ from extras.choices import *
 from extras.constants import CUSTOMFIELD_EMPTY_VALUES
 from extras.utils import is_taggable
 from netbox.config import get_config
+from netbox.constants import CORE_APPS
 from netbox.models.deletion import DeleteMixin
+from netbox.plugins import PluginConfig
 from netbox.registry import registry
 from netbox.signals import post_clean
 from utilities.json import CustomFieldJSONEncoder
@@ -32,12 +35,16 @@ __all__ = (
     'CustomValidationMixin',
     'EventRulesMixin',
     'ExportTemplatesMixin',
+    'FEATURES_MAP',
     'ImageAttachmentsMixin',
     'JobsMixin',
     'JournalingMixin',
     'NotificationsMixin',
     'SyncedDataMixin',
     'TagsMixin',
+    'get_model_features',
+    'has_feature',
+    'model_is_public',
     'register_models',
 )
 
@@ -639,11 +646,46 @@ FEATURES_MAP = {
     'tags': TagsMixin,
 }
 
+# TODO: Remove in NetBox v4.5
 registry['model_features'].update({
     feature: defaultdict(set) for feature in FEATURES_MAP.keys()
 })
 
 
+def model_is_public(model):
+    """
+    Return True if the model is considered "public use;" otherwise return False.
+
+    All non-core and non-plugin models are excluded.
+    """
+    opts = model._meta
+    if opts.app_label not in CORE_APPS and not isinstance(opts.app_config, PluginConfig):
+        return False
+    return not getattr(model, '_netbox_private', False)
+
+
+def get_model_features(model):
+    return [
+        feature for feature, cls in FEATURES_MAP.items() if issubclass(model, cls)
+    ]
+
+
+def has_feature(model_or_ct, feature):
+    """
+    Returns True if the model supports the specified feature.
+    """
+    # If an ObjectType was passed, we can use it directly
+    if type(model_or_ct) is ObjectType:
+        ot = model_or_ct
+    # If a ContentType was passed, resolve its model class
+    elif type(model_or_ct) is ContentType:
+        ot = ObjectType.objects.get_for_model(model_or_ct.model_class())
+    # For anything else, look up the ObjectType
+    else:
+        ot = ObjectType.objects.get_for_model(model_or_ct)
+    return feature in ot.features
+
+
 def register_models(*models):
     """
     Register one or more models in NetBox. This entails:
@@ -659,10 +701,12 @@ def register_models(*models):
     for model in models:
         app_label, model_name = model._meta.label_lower.split('.')
 
+        # TODO: Remove in NetBox v4.5
         # Register public models
         if not getattr(model, '_netbox_private', False):
             registry['models'][app_label].add(model_name)
 
+        # TODO: Remove in NetBox v4.5
         # Record each applicable feature for the model in the registry
         features = {
             feature for feature, cls in FEATURES_MAP.items() if issubclass(model, cls)

netbox/netbox/tests/test_model_features.py

@@ -0,0 +1,53 @@
+from django.test import TestCase
+
+from core.models import AutoSyncRecord, DataSource
+from extras.models import CustomLink
+from netbox.models.features import get_model_features, has_feature, model_is_public
+from netbox.tests.dummy_plugin.models import DummyModel
+from taggit.models import Tag
+
+
+class ModelFeaturesTestCase(TestCase):
+
+    def test_model_is_public(self):
+        """
+        Test that the is_public() utility function returns True for public models only.
+        """
+        # Public model
+        self.assertFalse(hasattr(DataSource, '_netbox_private'))
+        self.assertTrue(model_is_public(DataSource))
+
+        # Private model
+        self.assertTrue(getattr(AutoSyncRecord, '_netbox_private'))
+        self.assertFalse(model_is_public(AutoSyncRecord))
+
+        # Plugin model
+        self.assertFalse(hasattr(DummyModel, '_netbox_private'))
+        self.assertTrue(model_is_public(DummyModel))
+
+        # Non-core model
+        self.assertFalse(hasattr(Tag, '_netbox_private'))
+        self.assertFalse(model_is_public(Tag))
+
+    def test_has_feature(self):
+        """
+        Test the functionality of the has_feature() utility function.
+        """
+        # Sanity checking
+        self.assertTrue(hasattr(DataSource, 'bookmarks'), "Invalid test?")
+        self.assertFalse(hasattr(AutoSyncRecord, 'bookmarks'), "Invalid test?")
+
+        self.assertTrue(has_feature(DataSource, 'bookmarks'))
+        self.assertFalse(has_feature(AutoSyncRecord, 'bookmarks'))
+
+    def test_get_model_features(self):
+        """
+        Check that get_model_features() returns the expected features for a model.
+        """
+        # Sanity checking
+        self.assertTrue(hasattr(CustomLink, 'clone'), "Invalid test?")
+        self.assertFalse(hasattr(CustomLink, 'bookmarks'), "Invalid test?")
+
+        features = get_model_features(CustomLink)
+        self.assertIn('cloning', features)
+        self.assertNotIn('bookmarks', features)

netbox/netbox/tests/test_plugins.py

@@ -6,6 +6,7 @@ from django.test import Client, TestCase, override_settings
 from django.urls import reverse
 
 from core.choices import JobIntervalChoices
+from core.models import ObjectType
 from netbox.tests.dummy_plugin import config as dummy_config
 from netbox.tests.dummy_plugin.data_backends import DummyBackend
 from netbox.tests.dummy_plugin.jobs import DummySystemJob
@@ -23,8 +24,9 @@ class PluginTest(TestCase):
         self.assertIn('netbox.tests.dummy_plugin.DummyPluginConfig', settings.INSTALLED_APPS)
 
     def test_model_registration(self):
-        self.assertIn('dummy_plugin', registry['models'])
-        self.assertIn('dummymodel', registry['models']['dummy_plugin'])
+        self.assertTrue(
+            ObjectType.objects.filter(app_label='dummy_plugin', model='dummymodel').exists()
+        )
 
     def test_models(self):
         from netbox.tests.dummy_plugin.models import DummyModel

netbox/tenancy/models/contacts.py

@@ -4,9 +4,8 @@ from django.db import models
 from django.urls import reverse
 from django.utils.translation import gettext_lazy as _
 
-from core.models import ObjectType
 from netbox.models import ChangeLoggedModel, NestedGroupModel, OrganizationalModel, PrimaryModel
-from netbox.models.features import CustomFieldsMixin, ExportTemplatesMixin, TagsMixin
+from netbox.models.features import CustomFieldsMixin, ExportTemplatesMixin, TagsMixin, has_feature
 from tenancy.choices import *
 
 __all__ = (
@@ -151,7 +150,7 @@ class ContactAssignment(CustomFieldsMixin, ExportTemplatesMixin, TagsMixin, Chan
         super().clean()
 
         # Validate the assigned object type
-        if self.object_type not in ObjectType.objects.with_feature('contacts'):
+        if not has_feature(self.object_type, 'contacts'):
             raise ValidationError(
                 _("Contacts cannot be assigned to this object type ({type}).").format(type=self.object_type)
             )

netbox/users/migrations/0010_concrete_objecttype.py

@@ -0,0 +1,17 @@
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('contenttypes', '0002_remove_content_type_name'),
+        ('users', '0009_update_group_perms'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='objectpermission',
+            name='object_types',
+            field=models.ManyToManyField(related_name='object_permissions', to='contenttypes.contenttype'),
+        ),
+    ]

netbox/users/models/permissions.py

@@ -29,7 +29,7 @@ class ObjectPermission(models.Model):
         default=True
     )
     object_types = models.ManyToManyField(
-        to='core.ObjectType',
+        to='contenttypes.ContentType',
         related_name='object_permissions'
     )
     actions = ArrayField(

netbox/utilities/testing/filtersets.py

@@ -1,19 +1,17 @@
-import django_filters
 from datetime import datetime, timezone
 from itertools import chain
-from mptt.models import MPTTModel
 
+import django_filters
 from django.contrib.contenttypes.fields import GenericForeignKey, GenericRelation
 from django.contrib.contenttypes.models import ContentType
 from django.db.models import ForeignKey, ManyToManyField, ManyToManyRel, ManyToOneRel, OneToOneRel
 from django.utils.module_loading import import_string
+from mptt.models import MPTTModel
 from taggit.managers import TaggableManager
 
 from extras.filters import TagFilter
 from utilities.filters import ContentTypeFilter, TreeNodeMultipleChoiceFilter
 
-from core.models import ObjectType
-
 __all__ = (
     'BaseFilterSetTests',
     'ChangeLoggedFilterSetTests',
@@ -61,13 +59,6 @@ class BaseFilterSetTests:
             if field.related_model is ContentType:
                 return [(None, None)]
 
-            # ForeignKeys to ObjectType need two filters: 'app.model' & PK
-            if field.related_model is ObjectType:
-                return [
-                    (filter_name, ContentTypeFilter),
-                    (f'{filter_name}_id', django_filters.ModelMultipleChoiceFilter),
-                ]
-
             # ForeignKey to an MPTT-enabled model
             if issubclass(field.related_model, MPTTModel) and field.model is not field.related_model:
                 return [(f'{filter_name}_id', TreeNodeMultipleChoiceFilter)]
@@ -79,8 +70,10 @@ class BaseFilterSetTests:
             filter_name = self.get_m2m_filter_name(field)
             filter_name = self.filter_name_map.get(filter_name, filter_name)
 
-            # ManyToManyFields to ObjectType need two filters: 'app.model' & PK
-            if field.related_model is ObjectType:
+            # ManyToManyFields to ContentType need two filters: 'app.model' & PK
+            if field.related_model is ContentType:
+                # Standardize on object_type for filter name even though it's technically a ContentType
+                filter_name = 'object_type'
                 return [
                     (filter_name, ContentTypeFilter),
                     (f'{filter_name}_id', django_filters.ModelMultipleChoiceFilter),