Closes #12135: Prevent the deletion of interfaces with children (#14091)

* Closes #12135: Prevent the deletion of interfaces with children

* Change PROTECT to RESTRICT

* Extend handle_protectederror() to also handle RestrictedError

* Fix string translation

* Update migrations

* Support bulk removal of parent interfaces via UI if all children are included

* Add support for the bulk deletion of restricted objects via REST API

netbox/dcim/api/views.py

@@ -24,6 +24,7 @@ from netbox.api.viewsets import NetBoxModelViewSet, MPTTLockedMixin
 from netbox.api.viewsets.mixins import SequentialBulkCreatesMixin
 from netbox.constants import NESTED_SERIALIZER_PREFIX
 from utilities.api import get_serializer_for_model
+from utilities.query_functions import CollateAsChar
 from utilities.utils import count_related
 from virtualization.models import VirtualMachine
 from . import serializers
@@ -505,6 +506,10 @@ class InterfaceViewSet(PathEndpointMixin, NetBoxModelViewSet):
     filterset_class = filtersets.InterfaceFilterSet
     brief_prefetch_fields = ['device']
 
+    def get_bulk_destroy_queryset(self):
+        # Ensure child interfaces are deleted prior to their parents
+        return self.get_queryset().order_by('device', 'parent', CollateAsChar('_name'))
+
 
 class FrontPortViewSet(PassThroughPortMixin, NetBoxModelViewSet):
     queryset = FrontPort.objects.prefetch_related(

netbox/dcim/migrations/0183_protect_child_interfaces.py

@@ -0,0 +1,19 @@
+# Generated by Django 4.2.6 on 2023-10-20 11:48
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('dcim', '0182_devicetype_exclude_from_utilization'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='interface',
+            name='parent',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.RESTRICT, related_name='child_interfaces', to='dcim.interface'),
+        ),
+    ]

netbox/dcim/models/device_components.py

@@ -537,7 +537,7 @@ class BaseInterface(models.Model):
     )
     parent = models.ForeignKey(
         to='self',
-        on_delete=models.SET_NULL,
+        on_delete=models.RESTRICT,
         related_name='child_interfaces',
         null=True,
         blank=True,

netbox/dcim/tests/test_api.py

@@ -1607,6 +1607,33 @@ class InterfaceTest(Mixins.ComponentTraceMixin, APIViewTestCases.APIViewTestCase
             },
         ]
 
+    def test_bulk_delete_child_interfaces(self):
+        interface1 = Interface.objects.get(name='Interface 1')
+        device = interface1.device
+        self.add_permissions('dcim.delete_interface')
+
+        # Create a child interface
+        child = Interface.objects.create(
+            device=device,
+            name='Interface 1A',
+            type=InterfaceTypeChoices.TYPE_VIRTUAL,
+            parent=interface1
+        )
+        self.assertEqual(device.interfaces.count(), 4)
+
+        # Attempt to delete only the parent interface
+        url = self._get_detail_url(interface1)
+        self.client.delete(url, **self.header)
+        self.assertEqual(device.interfaces.count(), 4)  # Parent was not deleted
+
+        # Attempt to bulk delete parent & child together
+        data = [
+            {"id": interface1.pk},
+            {"id": child.pk},
+        ]
+        self.client.delete(self._get_list_url(), data, format='json', **self.header)
+        self.assertEqual(device.interfaces.count(), 2)  # Child & parent were both deleted
+
 
 class FrontPortTest(APIViewTestCases.APIViewTestCase):
     model = FrontPort

netbox/dcim/tests/test_views.py

@@ -2531,6 +2531,36 @@ class InterfaceTestCase(ViewTestCases.DeviceComponentViewTestCase):
         response = self.client.get(reverse('dcim:interface_trace', kwargs={'pk': interface1.pk}))
         self.assertHttpStatus(response, 200)
 
+    def test_bulk_delete_child_interfaces(self):
+        interface1 = Interface.objects.get(name='Interface 1')
+        device = interface1.device
+        self.add_permissions('dcim.delete_interface')
+
+        # Create a child interface
+        child = Interface.objects.create(
+            device=device,
+            name='Interface 1A',
+            type=InterfaceTypeChoices.TYPE_VIRTUAL,
+            parent=interface1
+        )
+        self.assertEqual(device.interfaces.count(), 6)
+
+        # Attempt to delete only the parent interface
+        data = {
+            'confirm': True,
+        }
+        self.client.post(self._get_url('delete', interface1), data)
+        self.assertEqual(device.interfaces.count(), 6)  # Parent was not deleted
+
+        # Attempt to bulk delete parent & child together
+        data = {
+            'pk': [interface1.pk, child.pk],
+            'confirm': True,
+            '_confirm': True,  # Form button
+        }
+        self.client.post(self._get_url('bulk_delete'), data)
+        self.assertEqual(device.interfaces.count(), 4)  # Child & parent were both deleted
+
 
 class FrontPortTestCase(ViewTestCases.DeviceComponentViewTestCase):
     model = FrontPort

netbox/dcim/views.py

@@ -1,5 +1,4 @@
 import traceback
-from collections import defaultdict
 
 from django.contrib import messages
 from django.contrib.contenttypes.models import ContentType
@@ -26,6 +25,7 @@ from tenancy.views import ObjectContactsView
 from utilities.forms import ConfirmationForm
 from utilities.paginator import EnhancedPaginator, get_paginate_count
 from utilities.permissions import get_permission_for_model
+from utilities.query_functions import CollateAsChar
 from utilities.utils import count_related
 from utilities.views import GetReturnURLMixin, ObjectPermissionRequiredMixin, ViewTab, register_model_view
 from virtualization.models import VirtualMachine
@@ -2562,7 +2562,8 @@ class InterfaceBulkDisconnectView(BulkDisconnectView):
 
 
 class InterfaceBulkDeleteView(generic.BulkDeleteView):
-    queryset = Interface.objects.all()
+    # Ensure child interfaces are deleted prior to their parents
+    queryset = Interface.objects.order_by('device', 'parent', CollateAsChar('_name'))
     filterset = filtersets.InterfaceFilterSet
     table = tables.InterfaceTable