Closes: #282 - Add handling for max_custom_object_types config option (and configuration.md) (#300)

* Add handling for max_cots config option (and configuration.md)

* Rename to max_custom_object_types

* Add default_settings entry

* Lower default maximum to 50

---------

Co-authored-by: Jeremy Stretch <jstretch@netboxlabs.com>

Author: bctiemann

docs/configuration.md

@@ -0,0 +1,7 @@
+# Configuration Parameters
+
+## `max_custom_object_types`
+
+Default: 50
+
+The maximum number of Custom Object Types that may be created.

netbox_custom_objects/__init__.py

@@ -53,7 +53,10 @@ class CustomObjectsPluginConfig(PluginConfig):
     author_email = 'support@netboxlabs.com'
     base_url = "custom-objects"
     min_version = "4.4.0"
-    default_settings = {}
+    default_settings = {
+        # The maximum number of Custom Object Types that may be created
+        'max_custom_object_types': 50,
+    }
     required_settings = []
     template_extensions = "template_content.template_extensions"
 

netbox_custom_objects/models.py

@@ -41,6 +41,7 @@
     TagsMixin,
     get_model_features,
 )
+from netbox.plugins import get_plugin_config
 from netbox.registry import registry
 from netbox.search import SearchIndex
 from utilities import filters
@@ -207,6 +208,7 @@ class CustomObjectType(NetBoxModel):
         blank=True,
         editable=False
     )
+
     class Meta:
         verbose_name = "Custom Object Type"
         ordering = ("name",)
@@ -223,6 +225,18 @@ class Meta:
     def __str__(self):
         return self.display_name
 
+    def clean(self):
+        super().clean()
+
+        # Enforce max number of COTs that may be created (max_custom_object_types)
+        if not self.pk:
+            max_cots = get_plugin_config("netbox_custom_objects", "max_custom_object_types")
+            if max_cots and CustomObjectType.objects.count() > max_cots:
+                raise ValidationError(_(
+                    f"Maximum number of Custom Object Types ({max_cots}) "
+                    "exceeded; adjust max_custom_object_types to raise this limit"
+                ))
+
     @classmethod
     def clear_model_cache(cls, custom_object_type_id=None):
         """