Source code for heat.engine.resources.stack_resource

#    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 json
import weakref

from oslo_config import cfg
from oslo_log import log as logging
from oslo_utils import excutils
from oslo_utils import reflection

from heat.common import exception
from heat.common.i18n import _
from heat.common import identifier
from heat.common import template_format
from heat.engine import attributes
from heat.engine import environment
from heat.engine import resource
from heat.engine import scheduler
from heat.engine import stack as parser
from heat.engine import stk_defn
from heat.engine import template
from heat.objects import raw_template
from heat.objects import stack as stack_object
from heat.objects import stack_lock
from heat.rpc import api as rpc_api

LOG = logging.getLogger(__name__)

[docs]class StackResource(resource.Resource): """Allows entire stack to be managed as a resource in a parent stack. An abstract Resource subclass that allows the management of an entire Stack as a resource in a parent stack. """ # Assume True as this is evaluated before the stack is created # so there is no way to know for sure without subclass-specific # template parsing. requires_deferred_auth = True def __init__(self, name, json_snippet, stack): super(StackResource, self).__init__(name, json_snippet, stack) self._nested = None self._outputs = None self.resource_info = None
[docs] def validate(self): super(StackResource, self).validate() # Don't redo a non-strict validation of a nested stack during the # creation of a child stack; only validate a child stack prior to the # creation of the root stack. if self.stack.nested_depth == 0 or not self.stack.strict_validate: self.validate_nested_stack()
[docs] def validate_nested_stack(self): try: name = "%s-%s" % (, nested_stack = self._parse_nested_stack( name, self.child_template(), self.child_params()) nested_stack.strict_validate = False nested_stack.validate() except AssertionError: raise except Exception as ex: path = "%s<%s>" % (, self.template_url) raise exception.StackValidationFailed( ex, path=[self.stack.t.RESOURCES, path])
@property def template_url(self): """Template url for the stack resource. When stack resource is a TemplateResource, it's the template location. For group resources like ResourceGroup where the template is constructed dynamically, it's just a placeholder. """ return "nested_stack" def _outputs_to_attribs(self, json_snippet): outputs = json_snippet.get('Outputs') if not self.attributes and outputs: self.attributes_schema = ( attributes.Attributes.schema_from_outputs(outputs)) # Note: it can be updated too and for show return dictionary # with all available outputs self.attributes = attributes.Attributes(, self.attributes_schema, self._make_resolver(weakref.ref(self))) def _needs_update(self, after, before, after_props, before_props, prev_resource, check_init_complete=True): # If the nested stack has not been created, use the default # implementation to determine if we need to replace the resource. Note # that we do *not* return the result. if self.resource_id is None: super(StackResource, self)._needs_update(after, before, after_props, before_props, prev_resource, check_init_complete) else: if self.state == (self.CHECK, self.FAILED): nested_stack = self.rpc_client().show_stack( self.context, self.nested_identifier())[0] nested_stack_state = (nested_stack[rpc_api.STACK_ACTION], nested_stack[rpc_api.STACK_STATUS]) if nested_stack_state == (self.stack.CHECK, self.stack.FAILED): # The stack-check action marked the stack resource # CHECK_FAILED, so return True to allow the individual # CHECK_FAILED resources decide if they need updating. return True # The mark-unhealthy action marked the stack resource # CHECK_FAILED, so raise UpdateReplace to replace the # entire failed stack. raise resource.UpdateReplace(self) # Always issue an update to the nested stack and let the individual # resources in it decide if they need updating. return True
[docs] def nested_identifier(self): if self.resource_id is None: return None return identifier.HeatIdentifier( self.context.tenant_id, self.physical_resource_name(), self.resource_id)
[docs] def has_nested(self): """Return True if the resource has an existing nested stack.""" return self.resource_id is not None or self._nested is not None
[docs] def nested(self): """Return a Stack object representing the nested (child) stack. If we catch NotFound exception when loading, return None. """ if self._nested is None and self.resource_id is not None: try: self._nested = parser.Stack.load(self.context, self.resource_id) except exception.NotFound: return None return self._nested
[docs] def child_template(self): """Default implementation to get the child template. Resources that inherit from StackResource should override this method with specific details about the template used by them. """ raise NotImplementedError()
[docs] def child_params(self): """Default implementation to get the child params. Resources that inherit from StackResource should override this method with specific details about the parameters used by them. """ raise NotImplementedError()
[docs] def preview(self): """Preview a StackResource as resources within a Stack. This method overrides the original Resource.preview to return a preview of all the resources contained in this Stack. For this to be possible, the specific resources need to override both ``child_template`` and ``child_params`` with specific information to allow the stack to be parsed correctly. If any of these methods is missing, the entire StackResource will be returned as if it were a regular Resource. """ try: child_template = self.child_template() params = self.child_params() except NotImplementedError: class_name = reflection.get_class_name(self, fully_qualified=False) LOG.warning("Preview of '%s' not yet implemented", class_name) return self name = "%s-%s" % (, self._nested = self._parse_nested_stack(name, child_template, params) return self.nested().preview_resources()
[docs] def get_nested_parameters_stack(self): """Return a stack for schema validation. This returns a stack to be introspected for building parameters schema. It can be customized by subclass to return a restricted version of what will be running. """ try: child_template = self.child_template() params = self.child_params() except NotImplementedError: class_name = reflection.get_class_name(self, fully_qualified=False) LOG.warning("Nested parameters of '%s' not yet " "implemented", class_name) return name = "%s-%s" % (, return self._parse_nested_stack(name, child_template, params)
def _parse_child_template(self, child_template, child_env): parsed_child_template = child_template if isinstance(parsed_child_template, template.Template): parsed_child_template = parsed_child_template.t return template.Template(parsed_child_template, files=self.child_template_files(child_env), env=child_env)
[docs] def child_template_files(self, child_env): """Default implementation to get the files map for child template.""" return self.stack.t.files
def _parse_nested_stack(self, stack_name, child_template, child_params, timeout_mins=None, adopt_data=None): if timeout_mins is None: timeout_mins = self.stack.timeout_mins stack_user_project_id = self.stack.stack_user_project_id new_nested_depth = self._child_nested_depth() child_env = environment.get_child_environment( self.stack.env, child_params,, item_to_remove=self.resource_info) parsed_template = self._child_parsed_template(child_template, child_env) self._validate_nested_resources(parsed_template) # Note we disable rollback for nested stacks, since they # should be rolled back by the parent stack on failure nested = parser.Stack(self.context, stack_name, parsed_template, timeout_mins=timeout_mins, disable_rollback=True,,, user_creds_id=self.stack.user_creds_id, stack_user_project_id=stack_user_project_id, adopt_stack_data=adopt_data, nested_depth=new_nested_depth) nested.set_parent_stack(self.stack) return nested def _child_nested_depth(self): if self.stack.nested_depth >= cfg.CONF.max_nested_stack_depth: msg = _("Recursion depth exceeds %d." ) % cfg.CONF.max_nested_stack_depth raise exception.RequestLimitExceeded(message=msg) return self.stack.nested_depth + 1 def _child_parsed_template(self, child_template, child_env): parsed_template = self._parse_child_template(child_template, child_env) # Don't overwrite the attributes_schema for subclasses that # define their own attributes_schema. if not hasattr(type(self), 'attributes_schema'): self.attributes = None self._outputs_to_attribs(parsed_template) return parsed_template def _validate_nested_resources(self, templ): if cfg.CONF.max_resources_per_stack == -1: return total_resources = (len(templ[templ.RESOURCES]) + self.stack.total_resources(self.root_stack_id)) identity = self.nested_identifier() if identity is not None: existing = self.rpc_client().list_stack_resources(self.context, identity) # Don't double-count existing resources during an update total_resources -= len(existing) if (total_resources > cfg.CONF.max_resources_per_stack): message = exception.StackResourceLimitExceeded.msg_fmt raise exception.RequestLimitExceeded(message=message)
[docs] def create_with_template(self, child_template, user_params=None, timeout_mins=None, adopt_data=None): """Create the nested stack with the given template.""" name = self.physical_resource_name() if timeout_mins is None: timeout_mins = self.stack.timeout_mins stack_user_project_id = self.stack.stack_user_project_id kwargs = self._stack_kwargs(user_params, child_template, adopt_data) adopt_data_str = None if adopt_data is not None: if 'environment' not in adopt_data: adopt_data['environment'] = kwargs['params'] if 'template' not in adopt_data: if isinstance(child_template, template.Template): adopt_data['template'] = child_template.t else: adopt_data['template'] = child_template adopt_data_str = json.dumps(adopt_data) args = {rpc_api.PARAM_TIMEOUT: timeout_mins, rpc_api.PARAM_DISABLE_ROLLBACK: True, rpc_api.PARAM_ADOPT_STACK_DATA: adopt_data_str} kwargs.update({ 'stack_name': name, 'args': args, 'environment_files': None, 'owner_id':, 'user_creds_id': self.stack.user_creds_id, 'stack_user_project_id': stack_user_project_id, 'nested_depth': self._child_nested_depth(), 'parent_resource_name': }) with self.translate_remote_exceptions: try: result = self.rpc_client()._create_stack(self.context, **kwargs) except exception.HeatException: with excutils.save_and_reraise_exception(): if adopt_data is None: raw_template.RawTemplate.delete(self.context, kwargs['template_id']) self.resource_id_set(result['stack_id'])
[docs] def child_definition(self, child_template=None, user_params=None, nested_identifier=None): if user_params is None: user_params = self.child_params() if child_template is None: child_template = self.child_template() if nested_identifier is None: nested_identifier = self.nested_identifier() child_env = environment.get_child_environment( self.stack.env, user_params,, item_to_remove=self.resource_info) parsed_template = self._child_parsed_template(child_template, child_env) return stk_defn.StackDefinition(self.context, parsed_template, nested_identifier, None)
def _stack_kwargs(self, user_params, child_template, adopt_data=None): defn = self.child_definition(child_template, user_params) parsed_template = defn.t if adopt_data is None: template_id = return { 'template_id': template_id, 'template': None, 'params': None, 'files': None, } else: return { 'template': parsed_template.t, 'params': defn.env.user_env_as_dict(), 'files': parsed_template.files, }
[docs] @excutils.exception_filter def translate_remote_exceptions(self, ex): if (isinstance(ex, exception.ActionInProgress) and self.stack.action == self.stack.ROLLBACK): # The update was interrupted and the rollback is already in # progress, so just ignore the error and wait for the rollback to # finish return True class_name = reflection.get_class_name(ex, fully_qualified=False) if not class_name.endswith('_Remote'): return False full_message = str(ex) if full_message.find('\n') > -1: message, msg_trace = full_message.split('\n', 1) else: message = full_message raise exception.ResourceFailure(message, self, action=self.action)
[docs] def check_create_complete(self, cookie=None): return self._check_status_complete(self.CREATE)
def _check_status_complete(self, expected_action, cookie=None): try: data = stack_object.Stack.get_status(self.context, self.resource_id) except exception.NotFound: if expected_action == self.DELETE: return True # It's possible the engine handling the create hasn't persisted # the stack to the DB when we first start polling for state return False action, status, status_reason, updated_time = data if action != expected_action: return False # Has the action really started? # # The rpc call to update does not guarantee that the stack will be # placed into IN_PROGRESS by the time it returns (it runs stack.update # in a thread) so you could also have a situation where we get into # this method and the update hasn't even started. # # So we are using a mixture of state (action+status) and updated_at # to see if the action has actually progressed. # - very fast updates (like something with one RandomString) we will # probably miss the state change, but we should catch the updated_at. # - very slow updates we won't see the updated_at for quite a while, # but should see the state change. if cookie is not None: prev_state = cookie['previous']['state'] prev_updated_at = cookie['previous']['updated_at'] if (prev_updated_at == updated_time and prev_state == (action, status)): return False if status == self.IN_PROGRESS: return False elif status == self.COMPLETE: # For operations where we do not take a resource lock # (i.e. legacy-style), check that the stack lock has been # released before reporting completeness. done = (self._should_lock_on_action(expected_action) or stack_lock.StackLock.get_engine_id( self.context, self.resource_id) is None) if done: # Reset nested, to indicate we changed status self._nested = None return done elif status == self.FAILED: raise exception.ResourceFailure(status_reason, self, action=action) else: raise exception.ResourceUnknownStatus( resource_status=status, status_reason=status_reason, result=_('Stack unknown status'))
[docs] def check_adopt_complete(self, cookie=None): return self._check_status_complete(self.ADOPT)
def _try_rollback(self): stack_identity = self.nested_identifier() if stack_identity is None: return False try: self.rpc_client().stack_cancel_update( self.context, dict(stack_identity), cancel_with_rollback=True) except exception.NotSupported: return False try: data = stack_object.Stack.get_status(self.context, self.resource_id) except exception.NotFound: return False action, status, status_reason, updated_time = data # If nested stack is still in progress, it should eventually roll # itself back due to stack_cancel_update(), so we just need to wait # for that to complete return status == self.stack.IN_PROGRESS
[docs] def update_with_template(self, child_template, user_params=None, timeout_mins=None): """Update the nested stack with the new template.""" if is None: if self.stack.action == self.stack.ROLLBACK: if self._try_rollback():'Triggered nested stack %s rollback', self.physical_resource_name()) return {'target_action': self.stack.ROLLBACK} if self.resource_id is None: # if the create failed for some reason and the nested # stack was not created, we need to create an empty stack # here so that the update will work. def _check_for_completion(): while not self.check_create_complete(): yield empty_temp = template_format.parse( "heat_template_version: '2013-05-23'") self.create_with_template(empty_temp, {}) checker = scheduler.TaskRunner(_check_for_completion) checker(timeout=self.stack.timeout_secs()) if timeout_mins is None: timeout_mins = self.stack.timeout_mins try: status_data = stack_object.Stack.get_status(self.context, self.resource_id) except exception.NotFound: raise resource.UpdateReplace(self) action, status, status_reason, updated_time = status_data kwargs = self._stack_kwargs(user_params, child_template) cookie = {'previous': { 'updated_at': updated_time, 'state': (action, status)}} kwargs.update({ 'stack_identity': dict(self.nested_identifier()), 'args': {rpc_api.PARAM_TIMEOUT: timeout_mins, rpc_api.PARAM_CONVERGE: self.converge} }) with self.translate_remote_exceptions: try: self.rpc_client()._update_stack(self.context, **kwargs) except exception.HeatException: with excutils.save_and_reraise_exception(): raw_template.RawTemplate.delete(self.context, kwargs['template_id']) return cookie
[docs] def check_update_complete(self, cookie=None): if cookie is not None and 'target_action' in cookie: target_action = cookie['target_action'] cookie = None else: target_action = self.stack.UPDATE return self._check_status_complete(target_action, cookie=cookie)
def _handle_cancel(self): stack_identity = self.nested_identifier() if stack_identity is not None: LOG.debug('Cancelling %s of %s' % (self.action, self)) try: self.rpc_client().stack_cancel_update( self.context, dict(stack_identity), cancel_with_rollback=False) except exception.NotSupported: LOG.debug('Nested stack %s not in cancellable state', stack_identity.stack_name)
[docs] def handle_preempt(self): self._handle_cancel()
[docs] def handle_update_cancel(self, cookie): self._handle_cancel()
[docs] def handle_create_cancel(self, cookie): return self.handle_update_cancel(cookie)
[docs] def delete_nested(self): """Delete the nested stack.""" stack_identity = self.nested_identifier() if stack_identity is None: return with self.rpc_client().ignore_error_by_name('EntityNotFound'): if self.abandon_in_progress: self.rpc_client().abandon_stack(self.context, stack_identity) else: self.rpc_client().delete_stack(self.context, stack_identity, cast=False)
[docs] def handle_delete(self): return self.delete_nested()
[docs] def check_delete_complete(self, cookie=None): return self._check_status_complete(self.DELETE)
[docs] def handle_suspend(self): stack_identity = self.nested_identifier() if stack_identity is None: raise exception.Error(_('Cannot suspend %s, stack not created') % self.rpc_client().stack_suspend(self.context, dict(stack_identity))
[docs] def check_suspend_complete(self, cookie=None): return self._check_status_complete(self.SUSPEND)
[docs] def handle_resume(self): stack_identity = self.nested_identifier() if stack_identity is None: raise exception.Error(_('Cannot resume %s, stack not created') % self.rpc_client().stack_resume(self.context, dict(stack_identity))
[docs] def check_resume_complete(self, cookie=None): return self._check_status_complete(self.RESUME)
[docs] def handle_check(self): stack_identity = self.nested_identifier() if stack_identity is None: raise exception.Error(_('Cannot check %s, stack not created') % self.rpc_client().stack_check(self.context, dict(stack_identity))
[docs] def check_check_complete(self, cookie=None): return self._check_status_complete(self.CHECK)
[docs] def prepare_abandon(self): self.abandon_in_progress = True nested_stack = self.nested() if nested_stack: return nested_stack.prepare_abandon() return {}
[docs] def get_output(self, op): """Return the specified Output value from the nested stack. If the output key does not exist, raise a NotFound exception. """ if (self._outputs is None or (op in self._outputs and rpc_api.OUTPUT_ERROR not in self._outputs[op] and self._outputs[op].get(rpc_api.OUTPUT_VALUE) is None)): stack_identity = self.nested_identifier() if stack_identity is None: return stack = self.rpc_client().show_stack(self.context, dict(stack_identity)) if not stack: return outputs = stack[0].get(rpc_api.STACK_OUTPUTS) or {} self._outputs = {o[rpc_api.OUTPUT_KEY]: o for o in outputs} if op not in self._outputs: raise exception.NotFound(_('Specified output key %s not ' 'found.') % op) output_data = self._outputs[op] if rpc_api.OUTPUT_ERROR in output_data: raise exception.TemplateOutputError(, attribute=op, message=output_data[rpc_api.OUTPUT_ERROR]) return output_data[rpc_api.OUTPUT_VALUE]
def _resolve_attribute(self, name): try: return self.get_output(name) except exception.NotFound: raise exception.InvalidTemplateAttribute(, key=name)