6347 Cache the number of each component type assigned to devices/VMs (#12632)

---------

Co-authored-by: Jeremy Stretch <jstretch@netboxlabs.com>

netbox/virtualization/api/serializers.py

@@ -80,12 +80,15 @@ class VirtualMachineSerializer(NetBoxModelSerializer):
     primary_ip4 = NestedIPAddressSerializer(required=False, allow_null=True)
     primary_ip6 = NestedIPAddressSerializer(required=False, allow_null=True)
 
+    # Counter fields
+    interface_count = serializers.IntegerField(read_only=True)
+
     class Meta:
         model = VirtualMachine
         fields = [
             'id', 'url', 'display', 'name', 'status', 'site', 'cluster', 'device', 'role', 'tenant', 'platform',
             'primary_ip', 'primary_ip4', 'primary_ip6', 'vcpus', 'memory', 'disk', 'description', 'comments',
-            'local_context_data', 'tags', 'custom_fields', 'created', 'last_updated',
+            'local_context_data', 'tags', 'custom_fields', 'created', 'last_updated', 'interface_count',
         ]
         validators = []
 
@@ -98,6 +101,7 @@ class VirtualMachineWithConfigContextSerializer(VirtualMachineSerializer):
             'id', 'url', 'display', 'name', 'status', 'site', 'cluster', 'device', 'role', 'tenant', 'platform',
             'primary_ip', 'primary_ip4', 'primary_ip6', 'vcpus', 'memory', 'disk', 'description', 'comments',
             'local_context_data', 'tags', 'custom_fields', 'config_context', 'created', 'last_updated',
+            'interface_count',
         ]
 
     @extend_schema_field(serializers.JSONField(allow_null=True))

netbox/virtualization/apps.py

@@ -6,3 +6,8 @@ class VirtualizationConfig(AppConfig):
 
     def ready(self):
         from . import search
+        from .models import VirtualMachine
+        from utilities.counters import connect_counters
+
+        # Register counters
+        connect_counters(VirtualMachine)

netbox/virtualization/migrations/0035_virtualmachine_interface_count.py

@@ -0,0 +1,35 @@
+from django.db import migrations
+from django.db.models import Count
+
+import utilities.fields
+
+
+def populate_virtualmachine_counts(apps, schema_editor):
+    VirtualMachine = apps.get_model('virtualization', 'VirtualMachine')
+
+    vms = list(VirtualMachine.objects.annotate(_interface_count=Count('interfaces', distinct=True)))
+
+    for vm in vms:
+        vm.interface_count = vm._interface_count
+
+    VirtualMachine.objects.bulk_update(vms, ['interface_count'])
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ('virtualization', '0034_standardize_description_comments'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='virtualmachine',
+            name='interface_count',
+            field=utilities.fields.CounterCacheField(
+                default=0, to_field='virtual_machine', to_model='virtualization.VMInterface'
+            ),
+        ),
+        migrations.RunPython(
+            code=populate_virtualmachine_counts,
+            reverse_code=migrations.RunPython.noop
+        ),
+    ]

netbox/virtualization/models/virtualmachines.py

@@ -11,9 +11,10 @@ from extras.models import ConfigContextModel
 from extras.querysets import ConfigContextModelQuerySet
 from netbox.config import get_config
 from netbox.models import NetBoxModel, PrimaryModel
-from utilities.fields import NaturalOrderingField
+from utilities.fields import CounterCacheField, NaturalOrderingField
 from utilities.ordering import naturalize_interface
 from utilities.query_functions import CollateAsChar
+from utilities.tracking import TrackingModelMixin
 from virtualization.choices import *
 
 __all__ = (
@@ -120,6 +121,12 @@ class VirtualMachine(PrimaryModel, ConfigContextModel):
         verbose_name='Disk (GB)'
     )
 
+    # Counter fields
+    interface_count = CounterCacheField(
+        to_model='virtualization.VMInterface',
+        to_field='virtual_machine'
+    )
+
     # Generic relation
     contacts = GenericRelation(
         to='tenancy.ContactAssignment'
@@ -222,7 +229,7 @@ class VirtualMachine(PrimaryModel, ConfigContextModel):
             return None
 
 
-class VMInterface(NetBoxModel, BaseInterface):
+class VMInterface(NetBoxModel, BaseInterface, TrackingModelMixin):
     virtual_machine = models.ForeignKey(
         to='virtualization.VirtualMachine',
         on_delete=models.CASCADE,

netbox/virtualization/tables/virtualmachines.py

@@ -1,10 +1,11 @@
 import django_tables2 as tables
+from django.utils.translation import gettext as _
+
 from dcim.tables.devices import BaseInterfaceTable
+from netbox.tables import NetBoxTable, columns
 from tenancy.tables import ContactsColumnMixin, TenancyColumnsMixin
 from virtualization.models import VirtualMachine, VMInterface
 
-from netbox.tables import NetBoxTable, columns
-
 __all__ = (
     'VirtualMachineTable',
     'VirtualMachineVMInterfaceTable',
@@ -70,6 +71,9 @@ class VirtualMachineTable(TenancyColumnsMixin, ContactsColumnMixin, NetBoxTable)
     tags = columns.TagColumn(
         url_name='virtualization:virtualmachine_list'
     )
+    interface_count = tables.Column(
+        verbose_name=_('Interfaces')
+    )
 
     class Meta(NetBoxTable.Meta):
         model = VirtualMachine

netbox/virtualization/views.py

@@ -349,7 +349,7 @@ class VirtualMachineInterfacesView(generic.ObjectChildrenView):
     template_name = 'virtualization/virtualmachine/interfaces.html'
     tab = ViewTab(
         label=_('Interfaces'),
-        badge=lambda obj: obj.interfaces.count(),
+        badge=lambda obj: obj.interface_count,
         permission='virtualization.view_vminterface',
         weight=500
     )