feat(dcim): Add device, module and rack count filters

Introduces `device_count`, `module_count` and `rack_count` filters to
enable queries based on the existence and count of the associated
device, module or rack instances.
Updates forms, filtersets, and GraphQL schema to support these filters,
along with tests for validation.

Fixes #19523

Author: pheus

netbox/dcim/api/serializers_/devicetypes.py

@@ -5,7 +5,7 @@
 
 from dcim.choices import *
 from dcim.models import DeviceType, ModuleType, ModuleTypeProfile
-from netbox.api.fields import AttributesField, ChoiceField, RelatedObjectCountField
+from netbox.api.fields import AttributesField, ChoiceField
 from netbox.api.serializers import PrimaryModelSerializer
 from netbox.choices import *
 from .manufacturers import ManufacturerSerializer
@@ -45,9 +45,7 @@ class DeviceTypeSerializer(PrimaryModelSerializer):
     device_bay_template_count = serializers.IntegerField(read_only=True)
     module_bay_template_count = serializers.IntegerField(read_only=True)
     inventory_item_template_count = serializers.IntegerField(read_only=True)
-
-    # Related object counts
-    device_count = RelatedObjectCountField('instances')
+    device_count = serializers.IntegerField(read_only=True)
 
     class Meta:
         model = DeviceType
@@ -100,12 +98,13 @@ class ModuleTypeSerializer(PrimaryModelSerializer):
         required=False,
         allow_null=True
     )
+    module_count = serializers.IntegerField(read_only=True)
 
     class Meta:
         model = ModuleType
         fields = [
             'id', 'url', 'display_url', 'display', 'profile', 'manufacturer', 'model', 'part_number', 'airflow',
             'weight', 'weight_unit', 'description', 'attributes', 'owner', 'comments', 'tags', 'custom_fields',
-            'created', 'last_updated',
+            'created', 'last_updated', 'module_count',
         ]
-        brief_fields = ('id', 'url', 'display', 'profile', 'manufacturer', 'model', 'description')
+        brief_fields = ('id', 'url', 'display', 'profile', 'manufacturer', 'model', 'description', 'module_count')

netbox/dcim/api/serializers_/racks.py

@@ -62,19 +62,18 @@ class RackBaseSerializer(PrimaryModelSerializer):
 
 
 class RackTypeSerializer(RackBaseSerializer):
-    manufacturer = ManufacturerSerializer(
-        nested=True
-    )
+    manufacturer = ManufacturerSerializer(nested=True)
+    rack_count = serializers.IntegerField(read_only=True)
 
     class Meta:
         model = RackType
         fields = [
             'id', 'url', 'display_url', 'display', 'manufacturer', 'model', 'slug', 'description', 'form_factor',
             'width', 'u_height', 'starting_unit', 'desc_units', 'outer_width', 'outer_height', 'outer_depth',
             'outer_unit', 'weight', 'max_weight', 'weight_unit', 'mounting_depth', 'description', 'owner', 'comments',
-            'tags', 'custom_fields', 'created', 'last_updated',
+            'tags', 'custom_fields', 'created', 'last_updated', 'rack_count',
         ]
-        brief_fields = ('id', 'url', 'display', 'manufacturer', 'model', 'slug', 'description')
+        brief_fields = ('id', 'url', 'display', 'manufacturer', 'model', 'slug', 'description', 'rack_count')
 
 
 class RackSerializer(RackBaseSerializer):

netbox/dcim/apps.py

@@ -11,7 +11,7 @@ def ready(self):
         from netbox.models.features import register_models
         from utilities.counters import connect_counters
         from . import signals, search  # noqa: F401
-        from .models import CableTermination, Device, DeviceType, VirtualChassis
+        from .models import CableTermination, Device, DeviceType, ModuleType, RackType, VirtualChassis
 
         # Register models
         register_models(*self.get_models())
@@ -31,4 +31,4 @@ def ready(self):
         })
 
         # Register counters
-        connect_counters(Device, DeviceType, VirtualChassis)
+        connect_counters(Device, DeviceType, ModuleType, RackType, VirtualChassis)

netbox/dcim/filtersets.py

@@ -317,6 +317,9 @@ class Meta:
         fields = (
             'id', 'model', 'slug', 'u_height', 'starting_unit', 'desc_units', 'outer_width', 'outer_height',
             'outer_depth', 'outer_unit', 'mounting_depth', 'weight', 'max_weight', 'weight_unit', 'description',
+
+            # Counters
+            'rack_count',
         )
 
     def search(self, queryset, name, value):
@@ -627,6 +630,7 @@ class Meta:
             'device_bay_template_count',
             'module_bay_template_count',
             'inventory_item_template_count',
+            'device_count',
         )
 
     def search(self, queryset, name, value):
@@ -747,7 +751,12 @@ class ModuleTypeFilterSet(AttributeFiltersMixin, PrimaryModelFilterSet):
 
     class Meta:
         model = ModuleType
-        fields = ('id', 'model', 'part_number', 'airflow', 'weight', 'weight_unit', 'description')
+        fields = (
+            'id', 'model', 'part_number', 'airflow', 'weight', 'weight_unit', 'description',
+
+            # Counters
+            'module_count',
+        )
 
     def search(self, queryset, name, value):
         if not value.strip():

netbox/dcim/forms/filtersets.py

@@ -317,7 +317,7 @@ class RackTypeFilterForm(RackBaseFilterForm):
     model = RackType
     fieldsets = (
         FieldSet('q', 'filter_id', 'tag', 'owner_id'),
-        FieldSet('manufacturer_id', 'form_factor', 'width', 'u_height', name=_('Rack Type')),
+        FieldSet('manufacturer_id', 'form_factor', 'width', 'u_height', 'rack_count', name=_('Rack Type')),
         FieldSet('starting_unit', 'desc_units', name=_('Numbering')),
         FieldSet('weight', 'max_weight', 'weight_unit', name=_('Weight')),
     )
@@ -327,6 +327,11 @@ class RackTypeFilterForm(RackBaseFilterForm):
         required=False,
         label=_('Manufacturer')
     )
+    rack_count = forms.IntegerField(
+        label=_('Rack count'),
+        required=False,
+        min_value=0,
+    )
     tag = TagFilterField(model)
 
 
@@ -498,7 +503,8 @@ class DeviceTypeFilterForm(PrimaryModelFilterSetForm):
     fieldsets = (
         FieldSet('q', 'filter_id', 'tag', 'owner_id'),
         FieldSet(
-            'manufacturer_id', 'default_platform_id', 'part_number', 'subdevice_role', 'airflow', name=_('Hardware')
+            'manufacturer_id', 'default_platform_id', 'part_number', 'device_count',
+            'subdevice_role', 'airflow', name=_('Hardware')
         ),
         FieldSet('has_front_image', 'has_rear_image', name=_('Images')),
         FieldSet(
@@ -522,6 +528,11 @@ class DeviceTypeFilterForm(PrimaryModelFilterSetForm):
         label=_('Part number'),
         required=False
     )
+    device_count = forms.IntegerField(
+        label=_('Device count'),
+        required=False,
+        min_value=0,
+    )
     subdevice_role = forms.MultipleChoiceField(
         label=_('Subdevice role'),
         choices=add_blank_choice(SubdeviceRoleChoices),
@@ -633,7 +644,10 @@ class ModuleTypeFilterForm(PrimaryModelFilterSetForm):
     model = ModuleType
     fieldsets = (
         FieldSet('q', 'filter_id', 'tag', 'owner_id'),
-        FieldSet('profile_id', 'manufacturer_id', 'part_number', 'airflow', name=_('Hardware')),
+        FieldSet(
+            'profile_id', 'manufacturer_id', 'part_number', 'module_count',
+            'airflow', name=_('Hardware')
+        ),
         FieldSet(
             'console_ports', 'console_server_ports', 'power_ports', 'power_outlets', 'interfaces',
             'pass_through_ports', name=_('Components')
@@ -655,6 +669,11 @@ class ModuleTypeFilterForm(PrimaryModelFilterSetForm):
         label=_('Part number'),
         required=False
     )
+    module_count = forms.IntegerField(
+        label=_('Module count'),
+        required=False,
+        min_value=0,
+    )
     console_ports = forms.NullBooleanField(
         required=False,
         label=_('Has console ports'),

netbox/dcim/graphql/filters.py

@@ -4,7 +4,7 @@
 import strawberry
 import strawberry_django
 from strawberry.scalars import ID
-from strawberry_django import FilterLookup
+from strawberry_django import ComparisonFilterLookup, FilterLookup
 
 from core.graphql.filter_mixins import ChangeLogFilterMixin
 from dcim import models
@@ -328,6 +328,9 @@ class DeviceTypeFilter(ImageAttachmentFilterMixin, PrimaryModelFilterMixin, Weig
     )
     default_platform_id: ID | None = strawberry_django.filter_field()
     part_number: FilterLookup[str] | None = strawberry_django.filter_field()
+    instances: Annotated['DeviceFilter', strawberry.lazy('dcim.graphql.filters')] | None = (
+        strawberry_django.filter_field()
+    )
     u_height: Annotated['FloatLookup', strawberry.lazy('netbox.graphql.filter_lookups')] | None = (
         strawberry_django.filter_field()
     )
@@ -385,6 +388,7 @@ class DeviceTypeFilter(ImageAttachmentFilterMixin, PrimaryModelFilterMixin, Weig
     device_bay_template_count: FilterLookup[int] | None = strawberry_django.filter_field()
     module_bay_template_count: FilterLookup[int] | None = strawberry_django.filter_field()
     inventory_item_template_count: FilterLookup[int] | None = strawberry_django.filter_field()
+    device_count: ComparisonFilterLookup[int] | None = strawberry_django.filter_field()
 
 
 @strawberry_django.filter_type(models.FrontPort, lookups=True)
@@ -685,6 +689,9 @@ class ModuleTypeFilter(ImageAttachmentFilterMixin, PrimaryModelFilterMixin, Weig
     profile_id: ID | None = strawberry_django.filter_field()
     model: FilterLookup[str] | None = strawberry_django.filter_field()
     part_number: FilterLookup[str] | None = strawberry_django.filter_field()
+    instances: Annotated['ModuleFilter', strawberry.lazy('dcim.graphql.filters')] | None = (
+        strawberry_django.filter_field()
+    )
     airflow: Annotated['ModuleAirflowEnum', strawberry.lazy('dcim.graphql.enums')] | None = (
         strawberry_django.filter_field()
     )
@@ -718,6 +725,7 @@ class ModuleTypeFilter(ImageAttachmentFilterMixin, PrimaryModelFilterMixin, Weig
     inventory_item_templates: (
         Annotated['InventoryItemTemplateFilter', strawberry.lazy('dcim.graphql.filters')] | None
     ) = strawberry_django.filter_field()
+    module_count: ComparisonFilterLookup[int] | None = strawberry_django.filter_field()
 
 
 @strawberry_django.filter_type(models.Platform, lookups=True)
@@ -846,6 +854,8 @@ class RackTypeFilter(RackBaseFilterMixin):
     manufacturer_id: ID | None = strawberry_django.filter_field()
     model: FilterLookup[str] | None = strawberry_django.filter_field()
     slug: FilterLookup[str] | None = strawberry_django.filter_field()
+    racks: Annotated['RackFilter', strawberry.lazy('dcim.graphql.filters')] | None = strawberry_django.filter_field()
+    rack_count: ComparisonFilterLookup[int] | None = strawberry_django.filter_field()
 
 
 @strawberry_django.filter_type(models.Rack, lookups=True)

netbox/dcim/graphql/types.py

@@ -358,6 +358,7 @@ class DeviceTypeType(PrimaryObjectType):
     device_bay_template_count: BigInt
     module_bay_template_count: BigInt
     inventory_item_template_count: BigInt
+    device_count: BigInt
     front_image: strawberry_django.fields.types.DjangoImageType | None
     rear_image: strawberry_django.fields.types.DjangoImageType | None
     manufacturer: Annotated["ManufacturerType", strawberry.lazy('dcim.graphql.types')]
@@ -605,6 +606,7 @@ class ModuleTypeProfileType(PrimaryObjectType):
     pagination=True
 )
 class ModuleTypeType(PrimaryObjectType):
+    module_count: BigInt
     profile: Annotated["ModuleTypeProfileType", strawberry.lazy('dcim.graphql.types')] | None
     manufacturer: Annotated["ManufacturerType", strawberry.lazy('dcim.graphql.types')]
 
@@ -709,6 +711,7 @@ class PowerPortTemplateType(ModularComponentTemplateType):
     pagination=True
 )
 class RackTypeType(PrimaryObjectType):
+    rack_count: BigInt
     manufacturer: Annotated["ManufacturerType", strawberry.lazy('dcim.graphql.types')]
 
 

netbox/dcim/migrations/0218_devicetype_device_count.py

@@ -0,0 +1,66 @@
+import utilities.fields
+from django.db import migrations
+from django.db.models import Count, OuterRef, Subquery
+
+
+def _populate_count_for_type(
+    apps, schema_editor, app_name: str, model_name: str, target_field: str, related_name: str = 'instances'
+):
+    """
+    Update a CounterCache field on the specified model by annotating the count of related instances.
+    """
+    Model = apps.get_model(app_name, model_name)
+    db_alias = schema_editor.connection.alias
+
+    count_subquery = (
+        Model.objects.using(db_alias)
+        .filter(pk=OuterRef('pk'))
+        .annotate(_instance_count=Count(related_name))
+        .values('_instance_count')
+    )
+    Model.objects.using(db_alias).update(**{target_field: Subquery(count_subquery)})
+
+
+def populate_device_type_device_count(apps, schema_editor):
+    _populate_count_for_type(apps, schema_editor, 'dcim', 'DeviceType', 'device_count')
+
+
+def populate_module_type_module_count(apps, schema_editor):
+    _populate_count_for_type(apps, schema_editor, 'dcim', 'ModuleType', 'module_count')
+
+
+def populate_rack_type_rack_count(apps, schema_editor):
+    _populate_count_for_type(apps, schema_editor, 'dcim', 'RackType', 'rack_count', related_name='racks')
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ('dcim', '0217_owner'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='devicetype',
+            name='device_count',
+            field=utilities.fields.CounterCacheField(
+                default=0, editable=False, to_field='device_type', to_model='dcim.Device'
+            ),
+        ),
+        migrations.RunPython(populate_device_type_device_count, migrations.RunPython.noop),
+        migrations.AddField(
+            model_name='moduletype',
+            name='module_count',
+            field=utilities.fields.CounterCacheField(
+                default=0, editable=False, to_field='module_type', to_model='dcim.Module'
+            ),
+        ),
+        migrations.RunPython(populate_module_type_module_count, migrations.RunPython.noop),
+        migrations.AddField(
+            model_name='racktype',
+            name='rack_count',
+            field=utilities.fields.CounterCacheField(
+                default=0, editable=False, to_field='rack_type', to_model='dcim.Rack'
+            ),
+        ),
+        migrations.RunPython(populate_rack_type_rack_count, migrations.RunPython.noop),
+    ]

netbox/dcim/models/devices.py

@@ -185,6 +185,10 @@ class DeviceType(ImageAttachmentsMixin, PrimaryModel, WeightMixin):
         to_model='dcim.InventoryItemTemplate',
         to_field='device_type'
     )
+    device_count = CounterCacheField(
+        to_model='dcim.Device',
+        to_field='device_type'
+    )
 
     clone_fields = (
         'manufacturer', 'default_platform', 'u_height', 'is_full_depth', 'subdevice_role', 'airflow', 'weight',

netbox/dcim/models/modules.py

@@ -13,8 +13,10 @@
 from netbox.models import PrimaryModel
 from netbox.models.features import ImageAttachmentsMixin
 from netbox.models.mixins import WeightMixin
+from utilities.fields import CounterCacheField
 from utilities.jsonschema import validate_schema
 from utilities.string import title
+from utilities.tracking import TrackingModelMixin
 from .device_components import *
 
 __all__ = (
@@ -92,6 +94,10 @@ class ModuleType(ImageAttachmentsMixin, PrimaryModel, WeightMixin):
         null=True,
         verbose_name=_('attributes')
     )
+    module_count = CounterCacheField(
+        to_model='dcim.Module',
+        to_field='module_type'
+    )
 
     clone_fields = ('profile', 'manufacturer', 'weight', 'weight_unit', 'airflow')
     prerequisite_models = (
@@ -186,7 +192,7 @@ def to_yaml(self):
         return yaml.dump(dict(data), sort_keys=False)
 
 
-class Module(PrimaryModel, ConfigContextModel):
+class Module(TrackingModelMixin, PrimaryModel, ConfigContextModel):
     """
     A Module represents a field-installable component within a Device which may itself hold multiple device components
     (for example, a line card within a chassis switch). Modules are instantiated from ModuleTypes.