1 files changed, 78 insertions, 0 deletions
diff --git a/vnftest/common/task_template.py b/vnftest/common/task_template.py
new file mode 100755
index 0000000..7872aed
--- /dev/null
+++ b/vnftest/common/task_template.py
@@ -0,0 +1,78 @@
+##############################################################################
+# Copyright 2018 EuropeanSoftwareMarketingLtd.
+# ===================================================================
+#  Licensed under the ApacheLicense, Version2.0 (the"License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#  http://www.apache.org/licenses/LICENSE-2.0
+#
+# software distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and limitations under
+# the License
+##############################################################################
+# vnftest comment: this is a modified copy of
+# yardstick/common/task_template.py
+
+from __future__ import absolute_import
+import re
+import jinja2
+import jinja2.meta
+import yaml
+
+
+def finalize_for_yaml(elem):
+    """Render Jinja2 output specifically for YAML files"""
+    # Jinaj2 by default converts None to 'None', we can't allow this
+    # we could convert to empty string '', or we can convert to null, aka ~
+    if elem is None:
+        return '~'
+    # convert data structures to inline YAML
+    # match builtin types because we shouldn't be trying to render complex types
+    if isinstance(elem, (dict, list)):
+        # remove newlines because we are injecting back into YAML
+        # use block style for single line
+        return yaml.safe_dump(elem, default_flow_style=True).replace('\n', '')
+    return elem
+
+
+class TaskTemplate(object):
+
+    @classmethod
+    def render(cls, task_template, **kwargs):
+        """Render jinja2 task template to Vnftest input task.
+
+        :param task_template: string that contains template
+        :param kwargs: Dict with template arguments
+        :returns:rendered template str
+        """
+
+        from six.moves import builtins
+
+        ast = jinja2.Environment().parse(task_template)
+        required_kwargs = jinja2.meta.find_undeclared_variables(ast)
+
+        missing = set(required_kwargs) - set(kwargs) - set(dir(builtins))
+        real_missing = [mis for mis in missing
+                        if is_really_missing(mis, task_template)]
+
+        if real_missing:
+            multi_msg = ("Please specify next template task arguments:%s")
+            single_msg = ("Please specify template task argument:%s")
+            raise TypeError((len(real_missing) > 1 and multi_msg or single_msg)
+                            % ", ".join(real_missing))
+        return jinja2.Template(task_template, finalize=finalize_for_yaml).render(**kwargs)
+
+
+def is_really_missing(mis, task_template):
+    # Removing variables that have default values from
+    # missing. Construction that won't be properly
+    # check is {% set x = x or 1}
+    if re.search(mis.join([r"{%\s*set\s+", "\s*=\s*", r"[^\w]+"]),
+                 task_template):
+        return False
+    # Also check for a default filter which can show up as
+    # a missing variable
+    if re.search(mis + r"\s*\|\s*default\(", task_template):
+        return False
+    return True