# # 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 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 import six 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 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__) 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 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() def validate_nested_stack(self): try: name = "%s-%s" % (self.stack.name, self.name) 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.name, 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.name, 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 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) 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 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 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() 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() 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.stack.name, self.name) self._nested = self._parse_nested_stack(name, child_template, params) return self.nested().preview_resources() 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.stack.t.files, env=child_env) 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, child_resource_name=self.name, item_to_remove=self.resource_info) parsed_template = self._child_parsed_template(child_template, child_env) # 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, parent_resource=self.name, owner_id=self.stack.id, 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) self._validate_nested_resources(parsed_template) # 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)) if self.nested(): # It's an update and these resources will be deleted total_resources -= len(self.nested().resources) if (total_resources > cfg.CONF.max_resources_per_stack): message = exception.StackResourceLimitExceeded.msg_fmt raise exception.RequestLimitExceeded(message=message) 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': self.stack.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': self.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']) def _stack_kwargs(self, user_params, child_template, adopt_data=None): if user_params is None: user_params = self.child_params() if child_template is None: child_template = self.child_template() child_env = environment.get_child_environment( self.stack.env, user_params, child_resource_name=self.name, item_to_remove=self.resource_info) parsed_template = self._child_parsed_template(child_template, child_env) if adopt_data is None: template_id = parsed_template.store(self.context) return { 'template_id': template_id, 'template': None, 'params': None, 'files': None, } else: return { 'template': parsed_template.t, 'params': child_env.user_env_as_dict(), 'files': parsed_template.files, } @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 = six.text_type(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) 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: ret = stack_lock.StackLock.get_engine_id( self.context, self.resource_id) is None if ret: # Reset nested, to indicate we changed status self._nested = None return ret 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')) 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 def update_with_template(self, child_template, user_params=None, timeout_mins=None): """Update the nested stack with the new template.""" if self.id is None: self.store() if self.stack.action == self.stack.ROLLBACK: if self._try_rollback(): LOG.info('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 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_update_cancel(self, cookie): stack_identity = self.nested_identifier() if stack_identity is not None: 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) def handle_create_cancel(self, cookie): return self.handle_update_cancel(cookie) 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) def handle_delete(self): return self.delete_nested() def check_delete_complete(self, cookie=None): return self._check_status_complete(self.DELETE) def handle_suspend(self): stack_identity = self.nested_identifier() if stack_identity is None: raise exception.Error(_('Cannot suspend %s, stack not created') % self.name) self.rpc_client().stack_suspend(self.context, dict(stack_identity)) def check_suspend_complete(self, cookie=None): return self._check_status_complete(self.SUSPEND) def handle_resume(self): stack_identity = self.nested_identifier() if stack_identity is None: raise exception.Error(_('Cannot resume %s, stack not created') % self.name) self.rpc_client().stack_resume(self.context, dict(stack_identity)) def check_resume_complete(self, cookie=None): return self._check_status_complete(self.RESUME) def handle_check(self): stack_identity = self.nested_identifier() if stack_identity is None: raise exception.Error(_('Cannot check %s, stack not created') % self.name) self.rpc_client().stack_check(self.context, dict(stack_identity)) def check_check_complete(self, cookie=None): return self._check_status_complete(self.CHECK) def prepare_abandon(self): self.abandon_in_progress = True nested_stack = self.nested() if nested_stack: return nested_stack.prepare_abandon() return {} 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. (Note that TemplateResource.get_attribute() relies on this particular exception, not KeyError, being raised if the key does not exist.) """ 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.InvalidTemplateAttribute(resource=self.name, key=op) output_data = self._outputs[op] if rpc_api.OUTPUT_ERROR in output_data: raise exception.TemplateOutputError( resource=self.name, attribute=op, message=output_data[rpc_api.OUTPUT_ERROR]) return output_data[rpc_api.OUTPUT_VALUE] def _resolve_attribute(self, name): return self.get_output(name)