Add support for external HOT template

An external HOT template is a separate yaml file in native
Heat format HOT. The external template is referenced in the task
file and used as template for a "context". Parameters required at
template instantiation are also configured in the task file.
See new sample file ping-hot.yaml

Change-Id: Ie2b7ea96ea90b75ca4e08a29e2223ceeb1474724
JIRA: YARDSTICK-24
Signed-off-by: Hans Feldt <hans.feldt@ericsson.com>

1 files changed, 63 insertions, 0 deletions

diff --git a/yardstick/common/template_format.py b/yardstick/common/template_format.py
new file mode 100644
index 000000000..881b7e45b
--- /dev/null
+++ b/yardstick/common/template_format.py
@@ -0,0 +1,63 @@
+#    Licensed under the Apache License, Version 2.0 (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
+#
+#    Unless required by applicable law or agreed to in writing, 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.
+
+# yardstick: this file is copied from python-heatclient and slightly modified
+
+import json
+import yaml
+
+if hasattr(yaml, 'CSafeLoader'):
+    yaml_loader = yaml.CSafeLoader
+else:
+    yaml_loader = yaml.SafeLoader
+
+if hasattr(yaml, 'CSafeDumper'):
+    yaml_dumper = yaml.CSafeDumper
+else:
+    yaml_dumper = yaml.SafeDumper
+
+
+def _construct_yaml_str(self, node):
+    # Override the default string handling function
+    # to always return unicode objects
+    return self.construct_scalar(node)
+yaml_loader.add_constructor(u'tag:yaml.org,2002:str', _construct_yaml_str)
+# Unquoted dates like 2013-05-23 in yaml files get loaded as objects of type
+# datetime.data which causes problems in API layer when being processed by
+# openstack.common.jsonutils. Therefore, make unicode string out of timestamps
+# until jsonutils can handle dates.
+yaml_loader.add_constructor(u'tag:yaml.org,2002:timestamp',
+                            _construct_yaml_str)
+
+
+def parse(tmpl_str):
+    '''Takes a string and returns a dict containing the parsed structure.
+
+    This includes determination of whether the string is using the
+    JSON or YAML format.
+    '''
+    if tmpl_str.startswith('{'):
+        tpl = json.loads(tmpl_str)
+    else:
+        try:
+            tpl = yaml.load(tmpl_str, Loader=yaml_loader)
+        except yaml.YAMLError as yea:
+            raise ValueError(yea)
+        else:
+            if tpl is None:
+                tpl = {}
+    # Looking for supported version keys in the loaded template
+    if not ('HeatTemplateFormatVersion' in tpl
+            or 'heat_template_version' in tpl
+            or 'AWSTemplateFormatVersion' in tpl):
+        raise ValueError("Template format version not found.")
+    return tpl