Fixes #10513: Disable the reassignment of a module to a new device

docs/release-notes/version-3.3.md

@@ -16,6 +16,7 @@
 * [#10461](https://github.com/netbox-community/netbox/issues/10461) - Enable filtering by read-only custom fields in the UI
 * [#10470](https://github.com/netbox-community/netbox/issues/10470) - Omit read-only custom fields from CSV import forms
 * [#10480](https://github.com/netbox-community/netbox/issues/10480) - Cable trace SVG links should not force a new window
+* [#10513](https://github.com/netbox-community/netbox/issues/10513) - Disable the reassignment of a module to a new device
 
 ---
 

netbox/dcim/forms/models.py

@@ -679,6 +679,7 @@ class ModuleForm(NetBoxModelForm):
         super().__init__(*args, **kwargs)
 
         if self.instance.pk:
+            self.fields['device'].disabled = True
             self.fields['replicate_components'].initial = False
             self.fields['replicate_components'].disabled = True
             self.fields['adopt_components'].initial = False

netbox/dcim/models/devices.py

@@ -987,6 +987,14 @@ class Module(NetBoxModel, ConfigContextModel):
     def get_absolute_url(self):
         return reverse('dcim:module', args=[self.pk])
 
+    def clean(self):
+        super().clean()
+
+        if self.module_bay.device != self.device:
+            raise ValidationError(
+                f"Module must be installed within a module bay belonging to the assigned device ({self.device})."
+            )
+
     def save(self, *args, **kwargs):
         is_new = self.pk is None
 

netbox/dcim/tests/test_views.py

@@ -1778,10 +1778,12 @@ class ModuleTestCase(
             ModuleBay(device=devices[0], name='Module Bay 2'),
             ModuleBay(device=devices[0], name='Module Bay 3'),
             ModuleBay(device=devices[0], name='Module Bay 4'),
+            ModuleBay(device=devices[0], name='Module Bay 5'),
             ModuleBay(device=devices[1], name='Module Bay 1'),
             ModuleBay(device=devices[1], name='Module Bay 2'),
             ModuleBay(device=devices[1], name='Module Bay 3'),
             ModuleBay(device=devices[1], name='Module Bay 4'),
+            ModuleBay(device=devices[1], name='Module Bay 5'),
         )
         ModuleBay.objects.bulk_create(module_bays)
 
@@ -1795,7 +1797,7 @@ class ModuleTestCase(
         tags = create_tags('Alpha', 'Bravo', 'Charlie')
 
         cls.form_data = {
-            'device': devices[1].pk,
+            'device': devices[0].pk,
             'module_bay': module_bays[3].pk,
             'module_type': module_types[0].pk,
             'serial': 'A',
@@ -1867,7 +1869,6 @@ class ModuleTestCase(
         self.assertIsNone(interface.module)
 
         # Create a module with adopted components
-        form_data['module_bay'] = ModuleBay.objects.filter(device=device).first()
         form_data['module_type'] = module_type
         form_data['replicate_components'] = False
         form_data['adopt_components'] = True