Consolidate redundant traceback rendering

netbox/extras/api/mixins.py

@@ -1,10 +1,7 @@
-import traceback
-
-from jinja2.exceptions import TemplateError
 from rest_framework.decorators import action
 from rest_framework.renderers import JSONRenderer
 from rest_framework.response import Response
-from rest_framework.status import HTTP_400_BAD_REQUEST
+from rest_framework.status import HTTP_400_BAD_REQUEST, HTTP_500_INTERNAL_SERVER_ERROR
 
 from netbox.api.authentication import TokenWritePermission
 from netbox.api.renderers import TextRenderer
@@ -47,23 +44,11 @@ class ConfigTemplateRenderMixin:
     def render_configtemplate(self, request, configtemplate, context):
         try:
             output = configtemplate.render(context=context)
-        except TemplateError as e:
-            if configtemplate.debug:
-                detail = traceback.format_exc()
-            else:
-                parts = [f"{type(e).__name__}: {e}"]
-                if getattr(e, 'name', None):
-                    parts.append(f"Template: {e.name}")
-                if getattr(e, 'lineno', None):
-                    parts.append(f"Line: {e.lineno}")
-                detail = "\n".join(parts)
-            return Response({'detail': detail}, status=500)
         except Exception as e:
-            if configtemplate.debug:
-                detail = traceback.format_exc()
-            else:
-                detail = f"{type(e).__name__}: {e}"
-            return Response({'detail': detail}, status=500)
+            return Response(
+                {'detail': configtemplate.format_render_error(e)},
+                status=HTTP_500_INTERNAL_SERVER_ERROR,
+            )
 
         # If the client has requested "text/plain", return the raw content.
         if request.accepted_renderer.format == 'txt':

netbox/extras/models/configs.py

@@ -1,9 +1,12 @@
+import traceback
+
 import jsonschema
 from django.conf import settings
 from django.core.validators import ValidationError
 from django.db import models
 from django.urls import reverse
 from django.utils.translation import gettext_lazy as _
+from jinja2.exceptions import TemplateError
 from jsonschema.exceptions import ValidationError as JSONValidationError
 
 from extras.models.mixins import RenderTemplateMixin
@@ -306,3 +309,21 @@ class ConfigTemplate(
         """
         self.template_code = self.data_file.data_as_string
     sync_data.alters_data = True
+
+    def format_render_error(self, exc):
+        """
+        Return a formatted error string for a rendering exception. When debug is enabled, the full
+        traceback is returned. Otherwise, a concise, user-facing message is returned.
+
+        Must be called from within the except block so that traceback.format_exc() is valid.
+        """
+        if self.debug:
+            return traceback.format_exc()
+        if isinstance(exc, TemplateError):
+            parts = [f"{type(exc).__name__}: {exc}"]
+            if getattr(exc, 'name', None):
+                parts.append(_("Template: {name}").format(name=exc.name))
+            if getattr(exc, 'lineno', None):
+                parts.append(_("Line: {lineno}").format(lineno=exc.lineno))
+            return "\n".join(parts)
+        return f"{type(exc).__name__}: {exc}"

netbox/extras/tables/tables.py

@@ -699,6 +699,7 @@ class ConfigTemplateTable(NetBoxTable):
     )
     debug = columns.BooleanColumn(
         verbose_name=_('Debug'),
+        false_mark=None
     )
     owner = tables.Column(
         linkify=True,

netbox/extras/views.py

@@ -1,4 +1,3 @@
-import traceback
 from datetime import datetime
 
 from django.contrib import messages
@@ -13,7 +12,6 @@ from django.utils import timezone
 from django.utils.module_loading import import_string
 from django.utils.translation import gettext as _
 from django.views.generic import View
-from jinja2.exceptions import TemplateError
 
 from core.choices import ManagedFileRootPathChoices
 from core.models import Job
@@ -1125,21 +1123,8 @@ class ObjectRenderConfigView(generic.ObjectView):
         if config_template:
             try:
                 rendered_config = config_template.render(context=context_data)
-            except TemplateError as e:
-                if config_template.debug:
-                    error_message = traceback.format_exc()
-                else:
-                    parts = [f"{type(e).__name__}: {e}"]
-                    if getattr(e, 'name', None):
-                        parts.append(_("Template: {name}").format(name=e.name))
-                    if getattr(e, 'lineno', None):
-                        parts.append(_("Line: {lineno}").format(lineno=e.lineno))
-                    error_message = "\n".join(parts)
             except Exception as e:
-                if config_template.debug:
-                    error_message = traceback.format_exc()
-                else:
-                    error_message = f"{type(e).__name__}: {e}"
+                error_message = config_template.format_render_error(e)
 
         return {
             'base_template': self.base_template,