Fixes: #15016 - Catch AssertionError from cable trace and throw ValidationError

netbox/dcim/exceptions.py

@@ -0,0 +1,2 @@
+class UnsupportedCablePath(Exception):
+    pass

netbox/dcim/models/cables.py

@@ -27,6 +27,7 @@
     'CableTermination',
 )
 
+from ..exceptions import UnsupportedCablePath
 
 trace_paths = Signal()
 
@@ -533,8 +534,8 @@ def from_origin(cls, terminations):
             return None
 
         # Ensure all originating terminations are attached to the same link
-        if len(terminations) > 1:
-            assert all(t.link == terminations[0].link for t in terminations[1:])
+        if len(terminations) > 1 and not all(t.link == terminations[0].link for t in terminations[1:]):
+            raise UnsupportedCablePath(_("All originating terminations must start must be attached to the same link"))
 
         path = []
         position_stack = []
@@ -545,12 +546,13 @@ def from_origin(cls, terminations):
         while terminations:
 
             # Terminations must all be of the same type
-            assert all(isinstance(t, type(terminations[0])) for t in terminations[1:])
+            if not all(isinstance(t, type(terminations[0])) for t in terminations[1:]):
+                raise UnsupportedCablePath(_("All mid-span terminations must have the same termination type"))
 
             # All mid-span terminations must all be attached to the same device
-            if not isinstance(terminations[0], PathEndpoint):
-                assert all(isinstance(t, type(terminations[0])) for t in terminations[1:])
-                assert all(t.parent_object == terminations[0].parent_object for t in terminations[1:])
+            if (not isinstance(terminations[0], PathEndpoint) and not
+                    all(t.parent_object == terminations[0].parent_object for t in terminations[1:])):
+                raise UnsupportedCablePath(_("All mid-span terminations must have the same parent object"))
 
             # Check for a split path (e.g. rear port fanning out to multiple front ports with
             # different cables attached)
@@ -573,8 +575,10 @@ def from_origin(cls, terminations):
                     return None
                 # Otherwise, halt the trace if no link exists
                 break
-            assert all(type(link) in (Cable, WirelessLink) for link in links)
-            assert all(isinstance(link, type(links[0])) for link in links)
+            if not all(type(link) in (Cable, WirelessLink) for link in links):
+                raise UnsupportedCablePath(_("All links must be cable or wireless"))
+            if not all(isinstance(link, type(links[0])) for link in links):
+                raise UnsupportedCablePath(_("All links must match first link type"))
 
             # Step 3: Record asymmetric paths as split
             not_connected_terminations = [termination.link for termination in terminations if termination.link is None]
@@ -651,14 +655,18 @@ def from_origin(cls, terminations):
                     positions = position_stack.pop()
 
                     # Ensure we have a number of positions equal to the amount of remote terminations
-                    assert len(remote_terminations) == len(positions)
+                    if len(remote_terminations) != len(positions):
+                        raise UnsupportedCablePath(
+                            _("All positions counts within the path on opposite ends of links must match")
+                        )
 
                     # Get our front ports
                     q_filter = Q()
                     for rt in remote_terminations:
                         position = positions.pop()
                         q_filter |= Q(rear_port_id=rt.pk, rear_port_position=position)
-                    assert q_filter is not Q()
+                    if q_filter is Q():
+                        raise UnsupportedCablePath(_("Remote termination position filter is missing"))
                     front_ports = FrontPort.objects.filter(q_filter)
                 # Obtain the individual front ports based on the termination and position
                 elif position_stack:

netbox/dcim/tests/test_cablepaths.py

@@ -2,6 +2,7 @@
 
 from circuits.models import *
 from dcim.choices import LinkStatusChoices
+from dcim.exceptions import UnsupportedCablePath
 from dcim.models import *
 from dcim.svg import CableTraceSVG
 from dcim.utils import object_to_path_node
@@ -2261,7 +2262,7 @@ def test_401_exclude_midspan_devices(self):
             b_terminations=[frontport1, frontport3],
             label='C1'
         )
-        with self.assertRaises(AssertionError):
+        with self.assertRaises(UnsupportedCablePath):
             cable1.save()
 
         self.assertPathDoesNotExist(
@@ -2280,7 +2281,7 @@ def test_401_exclude_midspan_devices(self):
             label='C3'
         )
 
-        with self.assertRaises(AssertionError):
+        with self.assertRaises(UnsupportedCablePath):
             cable3.save()
 
         self.assertPathDoesNotExist(

netbox/netbox/views/generic/object_views.py

@@ -13,6 +13,7 @@
 from django.utils.safestring import mark_safe
 from django.utils.translation import gettext as _
 
+from dcim.exceptions import UnsupportedCablePath
 from core.signals import clear_events
 from utilities.error_handlers import handle_protectederror
 from utilities.exceptions import AbortRequest, PermissionsViolation
@@ -319,6 +320,12 @@ def post(self, request, *args, **kwargs):
                 form.add_error(None, e.message)
                 clear_events.send(sender=self)
 
+            # Catch any validation errors thrown in the model.save() or form.save() methods
+            except UnsupportedCablePath as e:
+                logger.debug(e.message)
+                form.add_error(None, e.message)
+                clear_events.send(sender=self)
+
         else:
             logger.debug("Form validation failed")