Files
python-heatclient/heatclient/common/template_format.py
Peter Razumovsky 54a1715e34 Add option for detailed template error
Add option detailed_template_error for informative
error during template and environment parsing.

yaml.SafeLoader returns error with template snippet where
error has been occurred instead of CSafeLoader. But
CSafeLoader is faster. So, if user wants to get more
informative error, use slower but more detailed SafeLoader
for yaml loading.

Change-Id: Ied0a573a00eb5f564dea0c636da1301de5de9ea7
Closes-bug: #1496361
2015-10-09 09:23:33 +03:00

70 lines
2.5 KiB
Python

# 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.
import json
import yaml
from heatclient.openstack.common._i18n import _
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:
# NOTE(prazumovsky): we need to return more informative error for
# user, so use SafeLoader, which return error message with template
# snippet where error has been occurred.
try:
tpl = yaml.load(tmpl_str, Loader=yaml.SafeLoader)
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