Closes #10197: Add a cached counter field for virtual chassis members

netbox/dcim/models/devices.py

@@ -22,6 +22,7 @@ from netbox.config import ConfigItem
 from netbox.models import OrganizationalModel, PrimaryModel
 from utilities.choices import ColorChoices
 from utilities.fields import ColorField, CounterCacheField, NaturalOrderingField
+from utilities.tracking import TrackingModelMixin
 from .device_components import *
 from .mixins import WeightMixin
 
@@ -469,7 +470,7 @@ def update_interface_bridges(device, interface_templates, module=None):
             interface.save()
 
 
-class Device(PrimaryModel, ConfigContextModel):
+class Device(PrimaryModel, ConfigContextModel, TrackingModelMixin):
     """
     A Device represents a piece of physical hardware mounted within a Rack. Each Device is assigned a DeviceType,
     DeviceRole, and (optionally) a Platform. Device names are not required, however if one is set it must be unique.
@@ -1206,6 +1207,12 @@ class VirtualChassis(PrimaryModel):
         blank=True
     )
 
+    # Counter fields
+    member_count = CounterCacheField(
+        to_model='dcim.Device',
+        to_field='virtual_chassis'
+    )
+
     class Meta:
         ordering = ['name']
         verbose_name_plural = 'virtual chassis'