Source code for heat.common.template_format

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#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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#    under the License.

import collections

from oslo_config import cfg
from oslo_serialization import jsonutils
import yaml

from heat.common import exception
from heat.common.i18n import _

if hasattr(yaml, 'CSafeLoader'):
    _yaml_loader_base = yaml.CSafeLoader
    _yaml_loader_base = yaml.SafeLoader

[docs]class yaml_loader(_yaml_loader_base): def _construct_yaml_str(self, node): # Override the default string handling function # to always return unicode objects return self.construct_scalar(node)
if hasattr(yaml, 'CSafeDumper'): _yaml_dumper_base = yaml.CSafeDumper else: _yaml_dumper_base = yaml.SafeDumper
[docs]class yaml_dumper(_yaml_dumper_base):
[docs] def represent_ordered_dict(self, data): return self.represent_dict(data.items())
yaml_loader.add_constructor(u',2002:str', yaml_loader._construct_yaml_str) # Unquoted dates like 2013-05-23 in yaml files get loaded as objects of type # 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',2002:timestamp', yaml_loader._construct_yaml_str) yaml_dumper.add_representer(collections.OrderedDict, yaml_dumper.represent_ordered_dict)
[docs]def simple_parse(tmpl_str, tmpl_url=None): try: tpl = jsonutils.loads(tmpl_str) except ValueError: 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: if tmpl_url is None: tmpl_url = '[root stack]' yea = str(yea) msg = _('Error parsing template %(tmpl)s ' '%(yea)s') % {'tmpl': tmpl_url, 'yea': yea} raise ValueError(msg) else: if tpl is None: tpl = {} if not isinstance(tpl, dict): raise ValueError(_('The template is not a JSON object ' 'or YAML mapping.')) return tpl
[docs]def validate_template_limit(contain_str): """Validate limit for the template. Check if the contain exceeds allowed size range. """ if len(contain_str) > cfg.CONF.max_template_size: msg = _("Template size (%(actual_len)s bytes) exceeds maximum " "allowed size (%(limit)s bytes)." ) % {'actual_len': len(contain_str), 'limit': cfg.CONF.max_template_size} raise exception.RequestLimitExceeded(message=msg)
[docs]def parse(tmpl_str, tmpl_url=None): """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. """ # TODO(ricolin): Move this validation to api side. # Validate nested stack template. validate_template_limit(str(tmpl_str)) tpl = simple_parse(tmpl_str, tmpl_url) # 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
[docs]def convert_json_to_yaml(json_str): """Convert AWS JSON template format to Heat YAML format. :param json_str: a string containing the AWS JSON template format. :returns: the equivalent string containing the Heat YAML format. """ # parse the string as json to a python structure tpl = jsonutils.loads(json_str, object_pairs_hook=collections.OrderedDict) # Replace AWS format version with Heat format version def top_level_items(tpl): yield ("HeatTemplateFormatVersion", '2012-12-12') for k, v in tpl.items(): if k != 'AWSTemplateFormatVersion': yield k, v # dump python structure to yaml return yaml.dump(collections.OrderedDict(top_level_items(tpl)), Dumper=yaml_dumper)