feat: prevent device/address change when linked to CMDB

Author: kpetremann

netbox_cmdb/netbox_cmdb/models/bgp.py

@@ -8,10 +8,12 @@
 from utilities.choices import ChoiceSet
 from utilities.querysets import RestrictedQuerySet
 
+from netbox_cmdb import protect
 from netbox_cmdb.choices import AssetMonitoringStateChoices, AssetStateChoices
 from netbox_cmdb.constants import BGP_MAX_ASN, BGP_MIN_ASN
 
 
+@protect.from_device_name_change("device")
 class BGPGlobal(ChangeLoggedModel):
     """Global BGP configuration.
 
@@ -197,6 +199,7 @@ class Meta:
         abstract = True
 
 
+@protect.from_device_name_change("device")
 class BGPPeerGroup(BGPSessionCommon):
     """A BGP Peer Group contains a set of BGP neighbors that shares common attributes."""
 
@@ -229,6 +232,8 @@ def get_absolute_url(self):
         return reverse("plugins:netbox_cmdb:bgppeergroup", args=[self.pk])
 
 
+@protect.from_device_name_change("device")
+@protect.from_ip_address_change("local_address")
 class DeviceBGPSession(BGPSessionCommon):
     """A Device BGP Session is a BGP session from a given device's perspective.
     It contains BGP local parameters for the given devices (as the local address / ASN)."""

netbox_cmdb/netbox_cmdb/models/bgp_community_list.py

@@ -1,7 +1,10 @@
 from django.db import models
 from netbox.models import ChangeLoggedModel
 
+from netbox_cmdb import protect
 
+
+@protect.from_device_name_change("device")
 class BGPCommunityList(ChangeLoggedModel):
     """An object used in RoutePolicy object to filter on a list of BGP communities."""
 

netbox_cmdb/netbox_cmdb/models/interface.py

@@ -2,6 +2,7 @@
 from django.db import models
 from netbox.models import ChangeLoggedModel
 
+from netbox_cmdb import protect
 from netbox_cmdb.choices import AssetMonitoringStateChoices, AssetStateChoices
 
 FEC_CHOICES = [
@@ -22,6 +23,7 @@
 ]
 
 
+@protect.from_device_name_change("device")
 class DeviceInterface(ChangeLoggedModel):
     """A device interface configuration."""
 
@@ -67,6 +69,7 @@ class Meta:
         unique_together = ("device", "name")
 
 
+@protect.from_ip_address_change("ipv4_address", "ipv6_address")
 class LogicalInterface(ChangeLoggedModel):
     """A logical interface configuration."""
 

netbox_cmdb/netbox_cmdb/models/prefix_list.py

@@ -6,6 +6,8 @@
 from netbox.models import ChangeLoggedModel
 from utilities.choices import ChoiceSet
 
+from netbox_cmdb import protect
+
 
 class PrefixListIPVersionChoices(ChoiceSet):
     """Prefix list IP versions choices."""
@@ -19,6 +21,7 @@ class PrefixListIPVersionChoices(ChoiceSet):
     )
 
 
+@protect.from_device_name_change("device")
 class PrefixList(ChangeLoggedModel):
     """Prefix list main model."""
 

netbox_cmdb/netbox_cmdb/models/route_policy.py

@@ -4,10 +4,12 @@
 from netbox.models import ChangeLoggedModel
 from utilities.querysets import RestrictedQuerySet
 
+from netbox_cmdb import protect
 from netbox_cmdb.choices import DecisionChoice
 from netbox_cmdb.fields import CustomIPAddressField
 
 
+@protect.from_device_name_change("device")
 class RoutePolicy(ChangeLoggedModel):
     """
     A RoutePolicy contains a name and a description and is optionally linked to a Device.

netbox_cmdb/netbox_cmdb/models/snmp.py

@@ -1,6 +1,7 @@
 from django.db import models
 from netbox.models import ChangeLoggedModel
 
+from netbox_cmdb import protect
 from netbox_cmdb.choices import SNMPCommunityType
 
 
@@ -23,6 +24,7 @@ class Meta:
         verbose_name_plural = "SNMP Communities"
 
 
+@protect.from_device_name_change("device")
 class SNMP(ChangeLoggedModel):
     """A Snmp configuration"""
 

netbox_cmdb/netbox_cmdb/protect.py

@@ -0,0 +1,34 @@
+MODELS_LINKED_TO_DEVICE = {}
+MODELS_LINKED_TO_IP_ADDRESS = {}
+
+
+def from_device_name_change(*fields):
+    def decorator(cls):
+        if cls not in MODELS_LINKED_TO_DEVICE:
+            MODELS_LINKED_TO_DEVICE[cls] = set()
+
+        if not fields:
+            return cls
+
+        for field in fields:
+            MODELS_LINKED_TO_DEVICE[cls].add(field)
+
+        return cls
+
+    return decorator
+
+
+def from_ip_address_change(*fields):
+    def decorator(cls):
+        if cls not in MODELS_LINKED_TO_IP_ADDRESS:
+            MODELS_LINKED_TO_IP_ADDRESS[cls] = set()
+
+        if not fields:
+            return cls
+
+        for field in fields:
+            MODELS_LINKED_TO_IP_ADDRESS[cls].add(field)
+
+        return cls
+
+    return decorator

netbox_cmdb/netbox_cmdb/signals.py

@@ -1,6 +1,10 @@
-from django.db.models.signals import post_delete
+from dcim.models import Device
+from django.core.exceptions import ValidationError
+from django.db.models.signals import post_delete, pre_save
 from django.dispatch import receiver
+from ipam.models import IPAddress
 
+from netbox_cmdb import protect
 from netbox_cmdb.models.bgp import BGPSession
 
 
@@ -13,3 +17,60 @@ def clean_device_bgp_sessions(sender, instance, **kwargs):
     if instance.peer_b:
         b = instance.peer_b
         b.delete()
+
+
+@receiver(pre_save, sender=Device)
+def protect_from_device_name_change(sender, instance, **kwargs):
+    """Prevents any name changes for dcim.Device if there is a CMDB object linked to it.
+
+    Some models in the CMDB depends on NetBox Device native model.
+    If one changes the Device name, it might affect the CMDB as a side effect, and could cause
+    unwanted configuration changes.
+    """
+
+    if not instance.pk:
+        return
+
+    current = Device.objects.get(pk=instance.pk)
+
+    if current.name == instance.name:
+        return
+
+    for model, fields in protect.MODELS_LINKED_TO_DEVICE.items():
+        if not fields:
+            continue
+
+        for field in fields:
+            filter = {field: instance}
+            if model.objects.filter(**filter).exists():
+                raise ValidationError(
+                    f"Device name cannot be changed because it is linked to: {model}."
+                )
+
+
+@receiver(pre_save, sender=IPAddress)
+def protect_from_ip_address_change(sender, instance, **kwargs):
+    """Prevents any name changes for ipam.IPAddress if there is a CMDB object linked to it.
+
+    Some models in the CMDB depends on NetBox IPAddress native model.
+    If one changes the address, it might affect the CMDB as a side effect, and could cause
+    unwanted configuration changes.
+    """
+    if not instance.pk:
+        return
+
+    current = IPAddress.objects.get(pk=instance.pk)
+
+    if current.address.ip == instance.address.ip:
+        return
+
+    for model, fields in protect.MODELS_LINKED_TO_IP_ADDRESS.items():
+        if not fields:
+            continue
+
+        for field in fields:
+            filter = {field: instance}
+            if model.objects.filter(**filter).exists():
+                raise ValidationError(
+                    f"IP address cannot be changed because it is linked to: {model}."
+                )