deb-heat/heat/common/template_format.py

117 lines
3.8 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 itertools
import json
import re
from oslo.config import cfg
import yaml
from heat.common import exception
from heat.openstack.common.gettextutils import _
cfg.CONF.import_opt('max_template_size', 'heat.common.config')
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 simple_parse(tmpl_str):
try:
tpl = json.loads(tmpl_str)
except ValueError:
try:
tpl = yaml.load(tmpl_str, Loader=yaml_loader)
except yaml.YAMLError as yea:
raise ValueError(yea)
else:
if tpl is None:
tpl = {}
return tpl
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 len(tmpl_str) > cfg.CONF.max_template_size:
msg = (_('Template exceeds maximum allowed size (%s bytes)') %
cfg.CONF.max_template_size)
raise exception.RequestLimitExceeded(message=msg)
tpl = simple_parse(tmpl_str)
if not isinstance(tpl, dict):
raise ValueError(_('The template is not a JSON object '
'or YAML mapping.'))
# 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
def convert_json_to_yaml(json_str):
'''Convert a string containing the AWS JSON template format
to an equivalent string containing the Heat YAML format.
'''
# Replace AWS format version with Heat format version
json_str = re.sub('"AWSTemplateFormatVersion"\s*:\s*"[^"]+"\s*,',
'', json_str)
# insert a sortable order into the key to preserve file ordering
key_order = itertools.count()
def order_key(matchobj):
key = '%s"__%05d__order__%s" :' % (
matchobj.group(1),
next(key_order),
matchobj.group(2))
return key
key_re = re.compile('^(\s*)"([^"]+)"\s*:', re.M)
json_str = key_re.sub(order_key, json_str)
# parse the string as json to a python structure
tpl = yaml.load(json_str, Loader=yaml_loader)
# dump python structure to yaml
tpl["HeatTemplateFormatVersion"] = '2012-12-12'
yml = yaml.dump(tpl, Dumper=yaml_dumper)
# remove ordering from key names
yml = re.sub('__\d*__order__', '', yml)
return yml