Merge "Add a StackDefinition class"

Jenkins 6 years ago committed by Gerrit Code Review
commit 9327d2f859
  1. 3
  2. 2
  3. 219

@ -132,6 +132,9 @@ def _stack_id_output(resource_name, template_type='cfn'):
BASE_ATTRIBUTES = (SHOW_ATTR, ) = ('show', )
class Attributes(collections.Mapping):
"""Models a collection of Resource Attributes."""

@ -95,7 +95,7 @@ class PollDelay(Exception):
class Resource(status.ResourceStatus):
BASE_ATTRIBUTES = (SHOW, ) = ('show', )
BASE_ATTRIBUTES = (SHOW, ) = (attributes.SHOW_ATTR, )
# If True, this resource must be created before it can be referenced.
strict_dependency = True

@ -0,0 +1,219 @@
# 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
# 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 six
from heat.common import exception
from heat.engine import attributes
from heat.engine import status
class StackDefinition(object):
"""Class representing the definition of a Stack, but not its current state.
This is the interface through which template functions will access data
about the stack definition, including the template and current values of
resource reference IDs and attributes.
This API can be considered stable by third-party Template or Function
plugins, and no part of it should be changed or removed without an
appropriate deprecation process.
def __init__(self, context, template, stack_identifier, resource_data,
self._context = context
self._template = template
self._resource_data = {} if resource_data is None else resource_data
self._parent_info = parent_info
self._zones = None
self.parameters = template.parameters(stack_identifier,
self._resource_defns = None
self._resources = {}
def clone_with_new_template(self, new_template, stack_identifier,
"""Create a new StackDefinition with a different template."""
res_data = {} if clear_resource_data else dict(self._resource_data)
return type(self)(self._context, new_template, stack_identifier,
res_data, self._parent_info)
def t(self):
"""The stack's template."""
return self._template
def env(self):
"""The stack's environment."""
return self._template.env
def _load_rsrc_defns(self):
self._resource_defns = self._template.resource_definitions(self)
def resource_definition(self, resource_name):
"""Return the definition of the given resource."""
if self._resource_defns is None:
return self._resource_defns[resource_name]
def enabled_rsrc_names(self):
"""Return the set of names of all enabled resources in the template."""
if self._resource_defns is None:
return set(self._resource_defns)
def all_rsrc_names(self):
"""Return the set of names of all resources in the template.
This includes resources that are disabled due to false conditionals.
if hasattr(self._template, 'RESOURCES'):
return set(self._template.get(self._template.RESOURCES,
self._resource_defns or []))
return self.enabled_rsrc_names()
def get_availability_zones(self):
"""Return the list of Nova availability zones."""
if self._zones is None:
nova = self._context.clients.client('nova')
zones = nova.availability_zones.list(detailed=False)
self._zones = [zone.zoneName for zone in zones]
return self._zones
def __contains__(self, resource_name):
"""Return True if the given resource name is present and enabled."""
if self._resource_defns is not None:
return resource_name in self._resource_defns
# In Cfn templates, we need to know whether Ref refers to a
# resource or a parameter in order to parse the resource
# definitions
return resource_name in self._template[self._template.RESOURCES]
def __getitem__(self, resource_name):
"""Return a proxy for the given resource."""
if resource_name not in self._resources:
res_proxy = ResourceProxy(resource_name,
self._resources[resource_name] = res_proxy
return self._resources[resource_name]
def parent_resource(self):
"""Return a proxy for the parent resource.
Returns None if the stack is not a provider stack for a
return self._parent_info
class ResourceProxy(status.ResourceStatus):
"""A lightweight API for essential data about a resource.
This is the interface through which template functions will access data
about particular resources in the stack definition, such as the resource
definition and current values of reference IDs and attributes.
Resource proxies for some or all resources in the stack will potentially be
loaded for every check resource operation, so it is essential that this API
is implemented efficiently, using only the data received over RPC and
without reference to the resource data stored in the database.
This API can be considered stable by third-party Template or Function
plugins, and no part of it should be changed or removed without an
appropriate deprecation process.
__slots__ = ('name', '_definition', '_resource_data')
def __init__(self, name, definition, resource_data): = name
self._definition = definition
self._resource_data = resource_data
def t(self):
"""The resource definition."""
return self._definition
def _res_data(self):
assert self._resource_data is not None, "Resource data not available"
return self._resource_data
def attributes_schema(self):
"""A set of the valid top-level attribute names.
This is provided for backwards-compatibility for functions that require
a container with all of the valid attribute names in order to validate
the template. Other operations on it are invalid because we don't
actually have access to the attributes schema here; hence we return a
set instead of a dict.
return set(self._res_data().attribute_names())
def external_id(self):
"""The external ID of the resource."""
return self._definition.external_id()
def state(self):
"""The current state (action, status) of the resource."""
return self.action, self.status
def action(self):
"""The current action of the resource."""
if self._resource_data is None:
return self.INIT
return self._resource_data.action
def status(self):
"""The current status of the resource."""
if self._resource_data is None:
return self.COMPLETE
return self._resource_data.status
def FnGetRefId(self):
"""For the intrinsic function get_resource."""
if self._resource_data is None:
return self._resource_data.reference_id()
def FnGetAtt(self, attr, *path):
"""For the intrinsic function get_attr."""
if path:
attr = (attr,) + path
return self._res_data().attribute(attr)
except KeyError:
raise exception.InvalidTemplateAttribute(,
def FnGetAtts(self):
"""For the intrinsic function get_attr when getting all attributes.
:returns: a dict of all of the resource's attribute values, excluding
the "show" attribute.
all_attrs = self._res_data().attributes()
return dict((k, v) for k, v in six.iteritems(all_attrs)
if k != attributes.SHOW_ATTR)