heat/heat/engine/resources/aws/cfn/stack.py

114 lines
4.2 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.
from requests import exceptions
from heat.common import exception
from heat.common.i18n import _
from heat.common import template_format
from heat.common import urlfetch
from heat.engine import attributes
from heat.engine import properties
from heat.engine.resources import stack_resource
class NestedStack(stack_resource.StackResource):
"""Represents a child stack to allow composition of templates."""
PROPERTIES = (
TEMPLATE_URL, TIMEOUT_IN_MINS, PARAMETERS,
) = (
'TemplateURL', 'TimeoutInMinutes', 'Parameters',
)
properties_schema = {
TEMPLATE_URL: properties.Schema(
properties.Schema.STRING,
_('The URL of a template that specifies the stack to be created '
'as a resource.'),
required=True,
update_allowed=True
),
TIMEOUT_IN_MINS: properties.Schema(
properties.Schema.INTEGER,
_('The length of time, in minutes, to wait for the nested stack '
'creation.'),
update_allowed=True
),
PARAMETERS: properties.Schema(
properties.Schema.MAP,
_('The set of parameters passed to this nested stack.'),
update_allowed=True
),
}
def child_template(self):
template_url = self.properties[self.TEMPLATE_URL]
try:
template_data = urlfetch.get(template_url)
except (exceptions.RequestException, IOError) as r_exc:
raise ValueError(_("Could not fetch remote template '%(url)s': "
"%(exc)s") %
{'url': template_url,
'exc': r_exc})
return template_format.parse(template_data, template_url)
def child_params(self):
return self.properties[self.PARAMETERS]
def handle_adopt(self, resource_data=None):
return self._create_with_template(resource_adopt_data=resource_data)
def handle_create(self):
return self._create_with_template()
def _create_with_template(self, resource_adopt_data=None):
template = self.child_template()
return self.create_with_template(template,
self.child_params(),
self.properties[self.TIMEOUT_IN_MINS],
adopt_data=resource_adopt_data)
def get_attribute(self, key, *path):
if key and not key.startswith('Outputs.'):
raise exception.InvalidTemplateAttribute(resource=self.name,
key=key)
try:
attribute = self.get_output(key.partition('.')[-1])
except exception.NotFound:
raise exception.InvalidTemplateAttribute(resource=self.name,
key=key)
return attributes.select_from_attribute(attribute, path)
def get_reference_id(self):
identifier = self.nested_identifier()
if identifier is None:
return str(self.name)
return identifier.arn()
def handle_update(self, json_snippet, tmpl_diff, prop_diff):
# Nested stack template may be changed even if the prop_diff is empty.
self.properties = json_snippet.properties(self.properties_schema,
self.context)
return self.update_with_template(self.child_template(),
self.properties[self.PARAMETERS],
self.properties[self.TIMEOUT_IN_MINS])
def resource_mapping():
return {
'AWS::CloudFormation::Stack': NestedStack,
}