heat/heat/engine/stack_resource.py

108 lines
3.6 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
#
# 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 heat.common import exception
from heat.engine import environment
from heat.engine import resource
from heat.engine import parser
from heat.engine import scheduler
from heat.openstack.common import log as logging
logger = logging.getLogger(__name__)
class StackResource(resource.Resource):
'''
An abstract Resource subclass that allows the management of an entire Stack
as a resource in a parent stack.
'''
def __init__(self, name, json_snippet, stack):
super(StackResource, self).__init__(name, json_snippet, stack)
self._nested = None
def nested(self):
'''
Return a Stack object representing the nested (child) stack.
'''
if self._nested is None and self.resource_id is not None:
self._nested = parser.Stack.load(self.context,
self.resource_id)
if self._nested is None:
raise exception.NotFound('Nested stack not found in DB')
return self._nested
def create_with_template(self, child_template, user_params,
timeout_mins=None):
'''
Handle the creation of the nested stack from a given JSON template.
'''
template = parser.Template(child_template)
# Note we disable rollback for nested stacks, since they
# should be rolled back by the parent stack on failure
self._nested = parser.Stack(self.context,
self.physical_resource_name(),
template,
environment.Environment(user_params),
timeout_mins=timeout_mins,
disable_rollback=True)
nested_id = self._nested.store(self.stack)
self.resource_id_set(nested_id)
stack_creator = scheduler.TaskRunner(self._nested.create_task)
stack_creator.start(timeout=self._nested.timeout_secs())
return stack_creator
def check_create_complete(self, stack_creator):
done = stack_creator.step()
if done:
if self._nested.state != self._nested.CREATE_COMPLETE:
raise exception.Error(self._nested.state_description)
return done
def delete_nested(self):
'''
Delete the nested stack.
'''
try:
stack = self.nested()
except exception.NotFound:
logger.info("Stack not found to delete")
else:
if stack is not None:
stack.delete()
def get_output(self, op):
'''
Return the specified Output value from the nested stack.
If the output key does not exist, raise an InvalidTemplateAttribute
exception.
'''
stack = self.nested()
if stack is None:
return None
if op not in stack.outputs:
raise exception.InvalidTemplateAttribute(
resource=self.name, key=op)
return stack.output(op)