Implement sanity checking for JSON schema definitions

netbox/dcim/models/modules.py

@@ -4,8 +4,7 @@ from django.core.exceptions import ValidationError
 from django.db import models
 from django.db.models.signals import post_save
 from django.utils.translation import gettext_lazy as _
-from jsonschema.exceptions import SchemaError, ValidationError as JSONValidationError
+from jsonschema.exceptions import ValidationError as JSONValidationError
-from jsonschema.validators import Draft202012Validator as JSONSchemaValidator
 
 from dcim.choices import *
 from dcim.utils import update_interface_bridges
@@ -13,6 +12,7 @@ from extras.models import ConfigContextModel, CustomField
 from netbox.models import PrimaryModel
 from netbox.models.features import ImageAttachmentsMixin
 from netbox.models.mixins import WeightMixin
+from utilities.jsonschema import validate_schema
 from utilities.string import title
 from .device_components import *
 
@@ -52,12 +52,12 @@ class ModuleTypeProfile(PrimaryModel):
         super().clean()
 
         # Validate the schema definition
-        if self.schema:
+        if self.schema is not None:
             try:
-                JSONSchemaValidator.check_schema(self.schema)
+                validate_schema(self.schema)
-            except SchemaError as e:
+            except ValidationError as e:
                 raise ValidationError({
-                    'schema': _("Invalid schema: {error}").format(error=e)
+                    'schema': e.message,
                 })
 
 

netbox/utilities/jsonschema.py

@@ -4,7 +4,11 @@ from typing import Any
 
 from django import forms
 from django.contrib.postgres.forms import SimpleArrayField
+from django.core.exceptions import ValidationError
 from django.core.validators import RegexValidator
+from django.utils.translation import gettext_lazy as _
+from jsonschema.exceptions import SchemaError
+from jsonschema.validators import validator_for
 
 from utilities.string import title
 from utilities.validators import MultipleOfValidator
@@ -13,6 +17,7 @@ __all__ = (
     'JSONSchemaProperty',
     'PropertyTypeEnum',
     'StringFormatEnum',
+    'validate_schema',
 )
 
 
@@ -143,3 +148,19 @@ class JSONSchemaProperty:
             return FORM_FIELDS[self.type]
         except KeyError:
             raise ValueError(f"Unknown property type: {self.type}")
+
+
+def validate_schema(schema):
+    """
+    Check that a minimum JSON schema definition is defined.
+    """
+    # Provide some basic sanity checking (not provided by jsonschema)
+    if not schema or type(schema) is not dict:
+        raise ValidationError(_("Invalid JSON schema definition"))
+    if not schema.get('properties'):
+        raise ValidationError(_("JSON schema must define properties"))
+    try:
+        ValidatorClass = validator_for(schema)
+        ValidatorClass.check_schema(schema)
+    except SchemaError as e:
+        raise ValidationError(_("Invalid JSON schema definition: {error}").format(error=e))