Merge pull request #19570 from netbox-community/19490-jinja-template-fails-with-empty-include

Fixes #19490: restores nesting behavior of DataSource-based ConfigTemplate

netbox/extras/models/mixins.py

@@ -131,7 +131,7 @@ class RenderTemplateMixin(models.Model):
         """
         context = self.get_context(context=context, queryset=queryset)
         env_params = self.environment_params or {}
-        output = render_jinja2(self.template_code, context, env_params)
+        output = render_jinja2(self.template_code, context, env_params, getattr(self, 'data_file', None))
 
         # Replace CRLF-style line terminators
         output = output.replace('\r\n', '\n')

netbox/extras/tests/test_models.py

@@ -1,9 +1,12 @@
+import tempfile
+from pathlib import Path
+
 from django.forms import ValidationError
-from django.test import TestCase
+from django.test import tag, TestCase
 
-from core.models import ObjectType
+from core.models import DataSource, ObjectType
 from dcim.models import Device, DeviceRole, DeviceType, Location, Manufacturer, Platform, Region, Site, SiteGroup
-from extras.models import ConfigContext, Tag
+from extras.models import ConfigContext, ConfigTemplate, Tag
 from tenancy.models import Tenant, TenantGroup
 from utilities.exceptions import AbortRequest
 from virtualization.models import Cluster, ClusterGroup, ClusterType, VirtualMachine
@@ -33,8 +36,8 @@ class TagTest(TestCase):
         ]
 
         site = Site.objects.create(name='Site 1')
-        for tag in tags:
-            site.tags.add(tag)
+        for _tag in tags:
+            site.tags.add(_tag)
         site.save()
 
         site = Site.objects.first()
@@ -540,3 +543,66 @@ class ConfigContextTest(TestCase):
         device.local_context_data = 'foo'
         with self.assertRaises(ValidationError):
             device.clean()
+
+
+class ConfigTemplateTest(TestCase):
+    """
+    TODO: These test cases deal with the weighting, ordering, and deep merge logic of config context data.
+    """
+    MAIN_TEMPLATE = """
+    {%- include 'base.j2' %}
+    """.strip()
+    BASE_TEMPLATE = """
+    Hi
+    """.strip()
+
+    @classmethod
+    def _create_template_file(cls, templates_dir, file_name, content):
+        template_file_name = file_name
+        if not template_file_name.endswith('j2'):
+            template_file_name += '.j2'
+        temp_file_path = templates_dir / template_file_name
+
+        with open(temp_file_path, 'w') as f:
+            f.write(content)
+
+    @classmethod
+    def setUpTestData(cls):
+        temp_dir = tempfile.TemporaryDirectory()
+        templates_dir = Path(temp_dir.name) / "templates"
+        templates_dir.mkdir(parents=True, exist_ok=True)
+
+        cls._create_template_file(templates_dir, 'base.j2', cls.BASE_TEMPLATE)
+        cls._create_template_file(templates_dir, 'main.j2', cls.MAIN_TEMPLATE)
+
+        data_source = DataSource(
+            name="Test DataSource",
+            type="local",
+            source_url=str(templates_dir),
+        )
+        data_source.save()
+        data_source.sync()
+
+        base_config_template = ConfigTemplate(
+            name="BaseTemplate",
+            data_file=data_source.datafiles.filter(path__endswith='base.j2').first()
+        )
+        base_config_template.clean()
+        base_config_template.save()
+        cls.base_config_template = base_config_template
+
+        main_config_template = ConfigTemplate(
+            name="MainTemplate",
+            data_file=data_source.datafiles.filter(path__endswith='main.j2').first()
+        )
+        main_config_template.clean()
+        main_config_template.save()
+        cls.main_config_template = main_config_template
+
+    @tag('regression')
+    def test_config_template_with_data_source(self):
+        self.assertEqual(self.BASE_TEMPLATE, self.base_config_template.render({}))
+
+    @tag('regression')
+    def test_config_template_with_data_source_nested_templates(self):
+        self.assertEqual(self.BASE_TEMPLATE, self.main_config_template.render({}))

netbox/utilities/jinja2.py

@@ -49,11 +49,27 @@ class DataFileLoader(BaseLoader):
 # Utility functions
 #
 
-def render_jinja2(template_code, context, environment_params=None):
+def render_jinja2(template_code, context, environment_params=None, data_file=None):
     """
     Render a Jinja2 template with the provided context. Return the rendered content.
     """
     environment_params = environment_params or {}
+
+    if 'loader' not in environment_params:
+        if data_file:
+            loader = DataFileLoader(data_file.source)
+            loader.cache_templates({
+                data_file.path: template_code
+            })
+        else:
+            loader = BaseLoader()
+        environment_params['loader'] = loader
+
     environment = SandboxedEnvironment(**environment_params)
     environment.filters.update(get_config().JINJA2_FILTERS)
-    return environment.from_string(source=template_code).render(**context)
+
+    if data_file:
+        template = environment.get_template(data_file.path)
+    else:
+        template = environment.from_string(source=template_code)
+    return template.render(**context)