Catch exceptions when rendering device templates in UI

netbox/dcim/views.py

@@ -1,3 +1,5 @@
+import traceback
+
 from django.contrib import messages
 from django.contrib.contenttypes.models import ContentType
 from django.core.paginator import EmptyPage, PageNotAnInteger
@@ -10,6 +12,7 @@ from django.utils.html import escape
 from django.utils.safestring import mark_safe
 from django.utils.translation import gettext as _
 from django.views.generic import View
+from jinja2.exceptions import TemplateError
 
 from circuits.models import Circuit, CircuitTermination
 from extras.views import ObjectConfigContextView
@@ -2015,10 +2018,13 @@ class DeviceRenderConfigView(generic.ObjectView):
         context_data.update(**instance.get_config_context())
 
         # Render the config template
+        rendered_config = None
         if config_template := instance.get_config_template():
-            rendered_config = config_template.render(context=context_data)
-        else:
-            rendered_config = None
+            try:
+                rendered_config = config_template.render(context=context_data)
+            except TemplateError as e:
+                messages.error(request, f"An error occurred while rendering the template: {e}")
+                rendered_config = traceback.format_exc()
 
         return {
             'config_template': config_template,

netbox/extras/models/configs.py

@@ -4,6 +4,7 @@ from django.db import models
 from django.urls import reverse
 from django.utils import timezone
 from django.utils.translation import gettext as _
+from jinja2.exceptions import TemplateError
 from jinja2.sandbox import SandboxedEnvironment
 
 from extras.querysets import ConfigContextQuerySet

netbox/templates/dcim/device/render_config.html

@@ -36,7 +36,7 @@
   <div class="row">
     <div class="col">
       <div class="card">
-        {% if rendered_config %}
+        {% if config_template %}
           <pre class="card-body">{{ rendered_config }}</pre>
         {% else %}
           <div class="card-body text-muted">No configuration template found</div>