Merge "Allow using builtin functions in task templates"

rally/api.py

@@ -102,10 +102,16 @@ def task_template_render(task_template, **kwargs):
     :param kwargs: Dict with template arguments
     :returns: rendered template str
     """
+
+    # NOTE(boris-42): We have to import __builtin__ to get full list of builtin
+    #                 functions (e.g. range()). Unfortunately __builtins__
+    #                 doesn't return them (when it is not main module)
+    import __builtin__
+
     ast = jinja2.Environment().parse(task_template)
     required_kwargs = jinja2.meta.find_undeclared_variables(ast)
 
-    missing = set(required_kwargs) - set(kwargs)
+    missing = set(required_kwargs) - set(kwargs) - set(dir(__builtin__))
     # NOTE(boris-42): Removing variables that have default values from missing.
     #                 Construction that won't be properly checked is
     #                 {% set x = x or 1}

tests/unit/test_api.py

@@ -103,6 +103,10 @@ class APITestCase(test.TestCase):
         self.assertEqual(
             "5 = 5", api.task_template_render(template, a=2, b=3, c=5))
 
+    def test_task_template_render_builtin(self):
+        template = "{% for i in range(4) %}{{i}}{% endfor %}"
+        self.assertEqual("0123", api.task_template_render(template))
+
     def test_task_template_render_missing_args(self):
         self.assertRaises(TypeError, api.task_template_render, "{{a}}")