Closes #13086: Virtual circuits (#17933)

* WIP

* Add API tests

* Add remaining tests

* Add model docs

* Show virtual circuit connections on interfaces

* Misc cleanup per PR feedback

* Renumber migration

* Support nested terminations for virtual circuit bulk import

netbox/dcim/filtersets.py

@@ -4,7 +4,7 @@ from django.utils.translation import gettext as _
 from drf_spectacular.types import OpenApiTypes
 from drf_spectacular.utils import extend_schema_field
 
-from circuits.models import CircuitTermination
+from circuits.models import CircuitTermination, VirtualCircuit, VirtualCircuitTermination
 from extras.filtersets import LocalConfigContextFilterSet
 from extras.models import ConfigTemplate
 from ipam.filtersets import PrimaryIPFilterSet
@@ -1842,6 +1842,16 @@ class InterfaceFilterSet(
         queryset=WirelessLink.objects.all(),
         label=_('Wireless link')
     )
+    virtual_circuit_id = django_filters.ModelMultipleChoiceFilter(
+        field_name='virtual_circuit_termination__virtual_circuit',
+        queryset=VirtualCircuit.objects.all(),
+        label=_('Virtual circuit (ID)'),
+    )
+    virtual_circuit_termination_id = django_filters.ModelMultipleChoiceFilter(
+        field_name='virtual_circuit_termination',
+        queryset=VirtualCircuitTermination.objects.all(),
+        label=_('Virtual circuit termination (ID)'),
+    )
 
     class Meta:
         model = Interface

netbox/dcim/models/device_components.py

@@ -998,6 +998,14 @@ class Interface(ModularComponentModel, BaseInterface, CabledObjectModel, PathEnd
     def l2vpn_termination(self):
         return self.l2vpn_terminations.first()
 
+    @cached_property
+    def connected_endpoints(self):
+        # If this is a virtual interface, return the remote endpoint of the connected
+        # virtual circuit, if any.
+        if self.is_virtual and hasattr(self, 'virtual_circuit_termination'):
+            return self.virtual_circuit_termination.peer_terminations
+        return super().connected_endpoints
+
 
 #
 # Pass-through ports

netbox/dcim/tables/devices.py

@@ -649,6 +649,14 @@ class InterfaceTable(BaseInterfaceTable, ModularDeviceComponentTable, PathEndpoi
         url_name='dcim:interface_list'
     )
 
+    # Override PathEndpointTable.connection to accommodate virtual circuits
+    connection = columns.TemplateColumn(
+        accessor='_path__destinations',
+        template_code=INTERFACE_LINKTERMINATION,
+        verbose_name=_('Connection'),
+        orderable=False
+    )
+
     class Meta(DeviceComponentTable.Meta):
         model = models.Interface
         fields = (

netbox/dcim/tables/template_code.py

@@ -10,6 +10,20 @@ LINKTERMINATION = """
 {% endfor %}
 """
 
+INTERFACE_LINKTERMINATION = """
+{% load i18n %}
+{% if record.is_virtual and record.virtual_circuit_termination %}
+  {% for termination in record.connected_endpoints %}
+    <a href="{{ termination.interface.parent_object.get_absolute_url }}">{{ termination.interface.parent_object }}</a>
+    <i class="mdi mdi-chevron-right"></i>
+    <a href="{{ termination.interface.get_absolute_url }}">{{ termination.interface }}</a>
+    {% trans "via" %}
+    <a href="{{ termination.parent_object.get_absolute_url }}">{{ termination.parent_object }}</a>
+    {% if not forloop.last %}<br />{% endif %}
+  {% endfor %}
+{% else %}""" + LINKTERMINATION + """{% endif %}
+"""
+
 CABLE_LENGTH = """
 {% load helpers %}
 {% if record.length %}{{ record.length|floatformat:"-2" }} {{ record.length_unit }}{% endif %}