# 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. import base64 from datetime import datetime from eventlet.support import greenlets as greenlet from heat.engine import event from heat.common import exception from heat.openstack.common import excutils from heat.db import api as db_api from heat.common import identifier from heat.engine import timestamp from heat.engine.properties import Properties from heat.openstack.common import log as logging logger = logging.getLogger(__name__) _resource_classes = {} def get_types(): '''Return an iterator over the list of valid resource types.''' return iter(_resource_classes) def get_class(resource_type): '''Return the Resource class for a given resource type.''' cls = _resource_classes.get(resource_type) if cls is None: msg = "Unknown resource Type : %s" % resource_type raise exception.StackValidationFailed(message=msg) else: return cls def _register_class(resource_type, resource_class): logger.info(_('Registering resource type %s') % resource_type) if resource_type in _resource_classes: logger.warning(_('Replacing existing resource type %s') % resource_type) _resource_classes[resource_type] = resource_class class UpdateReplace(Exception): ''' Raised when resource update requires replacement ''' _message = _("The Resource %s requires replacement.") def __init__(self, resource_name='Unknown', message=_("The Resource %s requires replacement.")): try: msg = message % resource_name except TypeError: msg = message super(Exception, self).__init__(msg) class Metadata(object): ''' A descriptor for accessing the metadata of a resource while ensuring the most up-to-date data is always obtained from the database. ''' def __get__(self, resource, resource_class): '''Return the metadata for the owning resource.''' if resource is None: return None if resource.id is None: return resource.parsed_template('Metadata') rs = db_api.resource_get(resource.stack.context, resource.id) rs.refresh(attrs=['rsrc_metadata']) return rs.rsrc_metadata def __set__(self, resource, metadata): '''Update the metadata for the owning resource.''' if resource.id is None: raise exception.ResourceNotAvailable(resource_name=resource.name) rs = db_api.resource_get(resource.stack.context, resource.id) rs.update_and_save({'rsrc_metadata': metadata}) class Resource(object): # Status strings CREATE_IN_PROGRESS = 'IN_PROGRESS' CREATE_FAILED = 'CREATE_FAILED' CREATE_COMPLETE = 'CREATE_COMPLETE' DELETE_IN_PROGRESS = 'DELETE_IN_PROGRESS' DELETE_FAILED = 'DELETE_FAILED' DELETE_COMPLETE = 'DELETE_COMPLETE' UPDATE_IN_PROGRESS = 'UPDATE_IN_PROGRESS' UPDATE_FAILED = 'UPDATE_FAILED' UPDATE_COMPLETE = 'UPDATE_COMPLETE' # If True, this resource must be created before it can be referenced. strict_dependency = True created_time = timestamp.Timestamp(db_api.resource_get, 'created_at') updated_time = timestamp.Timestamp(db_api.resource_get, 'updated_at') metadata = Metadata() # Resource implementation set this to the subset of template keys # which are supported for handle_update, used by update_template_diff update_allowed_keys = () # Resource implementation set this to the subset of resource properties # supported for handle_update, used by update_template_diff_properties update_allowed_properties = () def __new__(cls, name, json, stack): '''Create a new Resource of the appropriate class for its type.''' if cls != Resource: # Call is already for a subclass, so pass it through return super(Resource, cls).__new__(cls) # Select the correct subclass to instantiate ResourceClass = get_class(json['Type']) return ResourceClass(name, json, stack) def __init__(self, name, json_snippet, stack): if '/' in name: raise ValueError(_('Resource name may not contain "/"')) self.stack = stack self.context = stack.context self.name = name self.json_snippet = json_snippet self.t = stack.resolve_static_data(json_snippet) self.cached_t = None self.properties = Properties(self.properties_schema, self.t.get('Properties', {}), self.stack.resolve_runtime_data, self.name) resource = db_api.resource_get_by_name_and_stack(self.context, name, stack.id) if resource: self.resource_id = resource.nova_instance self.state = resource.state self.state_description = resource.state_description self.id = resource.id else: self.resource_id = None self.state = None self.state_description = '' self.id = None def __eq__(self, other): '''Allow == comparison of two resources.''' # For the purposes of comparison, we declare two resource objects # equal if their names and parsed_templates are the same if isinstance(other, Resource): return (self.name == other.name) and ( self.parsed_template() == other.parsed_template()) return NotImplemented def __ne__(self, other): '''Allow != comparison of two resources.''' result = self.__eq__(other) if result is NotImplemented: return result return not result def type(self): return self.t['Type'] def identifier(self): '''Return an identifier for this resource.''' return identifier.ResourceIdentifier(resource_name=self.name, **self.stack.identifier()) def parsed_template(self, section=None, default={}, cached=False): ''' Return the parsed template data for the resource. May be limited to only one section of the data, in which case a default value may also be supplied. ''' if cached and self.cached_t: t = self.cached_t else: t = self.t if section is None: template = t else: template = t.get(section, default) return self.stack.resolve_runtime_data(template) def cache_template(self): ''' make a cache of the resource's parsed template this can then be used via parsed_template(cached=True) ''' self.cached_t = self.stack.resolve_runtime_data(self.t) def update_template_diff(self, json_snippet=None): ''' Returns the difference between json_template and self.t If something has been removed in json_snippet which exists in self.t we set it to None. If any keys have changed which are not in update_allowed_keys, raises UpdateReplace if the differing keys are not in update_allowed_keys ''' update_allowed_set = set(self.update_allowed_keys) # Create a set containing the keys in both current and update template current_template = self.parsed_template(cached=True) template_keys = set(current_template.keys()) new_template = self.stack.resolve_runtime_data(json_snippet) template_keys.update(set(new_template.keys())) # Create a set of keys which differ (or are missing/added) changed_keys_set = set([k for k in template_keys if current_template.get(k) != new_template.get(k)]) if not changed_keys_set.issubset(update_allowed_set): badkeys = changed_keys_set - update_allowed_set raise UpdateReplace(self.name) return dict((k, new_template.get(k)) for k in changed_keys_set) def update_template_diff_properties(self, json_snippet=None): ''' Returns the changed Properties between json_template and self.t If a property has been removed in json_snippet which exists in self.t we set it to None. If any properties have changed which are not in update_allowed_properties, raises UpdateReplace if the modified properties are not in the update_allowed_properties ''' update_allowed_set = set(self.update_allowed_properties) # Create a set containing the keys in both current and update template tmpl = self.parsed_template(cached=True) current_properties = tmpl.get('Properties', {}) template_properties = set(current_properties.keys()) updated_properties = json_snippet.get('Properties', {}) template_properties.update(set(updated_properties.keys())) # Create a set of keys which differ (or are missing/added) changed_properties_set = set(k for k in template_properties if current_properties.get(k) != updated_properties.get(k)) if not changed_properties_set.issubset(update_allowed_set): raise UpdateReplace(self.name) return dict((k, updated_properties.get(k)) for k in changed_properties_set) def __str__(self): return '%s "%s"' % (self.__class__.__name__, self.name) def _add_dependencies(self, deps, head, fragment): if isinstance(fragment, dict): for key, value in fragment.items(): if key in ('DependsOn', 'Ref', 'Fn::GetAtt'): if key == 'Fn::GetAtt': value, head = value try: target = self.stack.resources[value] except KeyError: raise exception.InvalidTemplateReference( resource=value, key=head) if key == 'DependsOn' or target.strict_dependency: deps += (self, target) else: self._add_dependencies(deps, key, value) elif isinstance(fragment, list): for item in fragment: self._add_dependencies(deps, head, item) def add_dependencies(self, deps): self._add_dependencies(deps, None, self.t) deps += (self, None) def keystone(self): return self.stack.clients.keystone() def nova(self, service_type='compute'): return self.stack.clients.nova(service_type) def swift(self): return self.stack.clients.swift() def quantum(self): return self.stack.clients.quantum() def cinder(self): return self.stack.clients.cinder() def create(self): ''' Create the resource. Subclasses should provide a handle_create() method to customise creation. ''' assert self.state is None, 'Resource create requested in invalid state' logger.info('creating %s' % str(self)) # Re-resolve the template, since if the resource Ref's # the AWS::StackId pseudo parameter, it will change after # the parser.Stack is stored (which is after the resources # are __init__'d, but before they are create()'d) self.t = self.stack.resolve_static_data(self.json_snippet) self.properties = Properties(self.properties_schema, self.t.get('Properties', {}), self.stack.resolve_runtime_data, self.name) try: self.properties.validate() self.state_set(self.CREATE_IN_PROGRESS) create_data = None if callable(getattr(self, 'handle_create', None)): create_data = self.handle_create() yield while not self.check_create_complete(create_data): yield except greenlet.GreenletExit: # Older versions of greenlet erroneously had GreenletExit inherit # from Exception instead of BaseException with excutils.save_and_reraise_exception(): try: self.state_set(self.CREATE_FAILED, 'Creation aborted') except Exception: logger.exception('Error marking resource as failed') except Exception as ex: logger.exception('create %s', str(self)) failure = exception.ResourceFailure(ex) self.state_set(self.CREATE_FAILED, str(failure)) raise failure except: with excutils.save_and_reraise_exception(): try: self.state_set(self.CREATE_FAILED, 'Creation aborted') except Exception: logger.exception('Error marking resource as failed') else: self.state_set(self.CREATE_COMPLETE) def check_create_complete(self, create_data): ''' Check if the resource is active (ready to move to the CREATE_COMPLETE state). By default this happens as soon as the handle_create() method has completed successfully, but subclasses may customise this by overriding this function. The return value of handle_create() is passed in to this function each time it is called. ''' return True def update(self, json_snippet=None): ''' update the resource. Subclasses should provide a handle_update() method to customise update, the base-class handle_update will fail by default. ''' assert json_snippet is not None, 'Must specify update json snippet' if self.state in (self.CREATE_IN_PROGRESS, self.UPDATE_IN_PROGRESS): raise exception.ResourceFailure(Exception( 'Resource update already requested')) logger.info('updating %s' % str(self)) try: self.state_set(self.UPDATE_IN_PROGRESS) properties = Properties(self.properties_schema, json_snippet.get('Properties', {}), self.stack.resolve_runtime_data, self.name) properties.validate() tmpl_diff = self.update_template_diff(json_snippet) prop_diff = self.update_template_diff_properties(json_snippet) if callable(getattr(self, 'handle_update', None)): result = self.handle_update(json_snippet, tmpl_diff, prop_diff) except UpdateReplace: logger.debug("Resource %s update requires replacement" % self.name) raise except Exception as ex: logger.exception('update %s : %s' % (str(self), str(ex))) failure = exception.ResourceFailure(ex) self.state_set(self.UPDATE_FAILED, str(failure)) raise failure else: self.t = self.stack.resolve_static_data(json_snippet) self.state_set(self.UPDATE_COMPLETE) def physical_resource_name(self): return '%s-%s' % (self.stack.name, self.name) def validate(self): logger.info('Validating %s' % str(self)) self.validate_deletion_policy(self.t) return self.properties.validate() @classmethod def validate_deletion_policy(cls, template): deletion_policy = template.get('DeletionPolicy', 'Delete') if deletion_policy not in ('Delete', 'Retain', 'Snapshot'): msg = 'Invalid DeletionPolicy %s' % deletion_policy raise exception.StackValidationFailed(message=msg) elif deletion_policy == 'Snapshot': if not callable(getattr(cls, 'handle_snapshot_delete', None)): msg = 'Snapshot DeletionPolicy not supported' raise exception.StackValidationFailed(message=msg) def delete(self): ''' Delete the resource. Subclasses should provide a handle_delete() method to customise deletion. ''' if self.state == self.DELETE_COMPLETE: return if self.state == self.DELETE_IN_PROGRESS: raise exception.Error('Resource deletion already in progress') # No need to delete if the resource has never been created if self.state is None: return initial_state = self.state logger.info('deleting %s' % str(self)) try: self.state_set(self.DELETE_IN_PROGRESS) deletion_policy = self.t.get('DeletionPolicy', 'Delete') if deletion_policy == 'Delete': if callable(getattr(self, 'handle_delete', None)): self.handle_delete() elif deletion_policy == 'Snapshot': if callable(getattr(self, 'handle_snapshot_delete', None)): self.handle_snapshot_delete(initial_state) except Exception as ex: logger.exception('Delete %s', str(self)) failure = exception.ResourceFailure(ex) self.state_set(self.DELETE_FAILED, str(failure)) raise failure except: with excutils.save_and_reraise_exception(): try: self.state_set(self.DELETE_FAILED, 'Deletion aborted') except Exception: logger.exception('Error marking resource deletion failed') else: self.state_set(self.DELETE_COMPLETE) def destroy(self): ''' Delete the resource and remove it from the database. ''' self.delete() if self.id is None: return try: db_api.resource_get(self.context, self.id).delete() except exception.NotFound: # Don't fail on delete if the db entry has # not been created yet. pass self.id = None def resource_id_set(self, inst): self.resource_id = inst if self.id is not None: try: rs = db_api.resource_get(self.context, self.id) rs.update_and_save({'nova_instance': self.resource_id}) except Exception as ex: logger.warn('db error %s' % str(ex)) def _store(self): '''Create the resource in the database.''' try: rs = {'state': self.state, 'stack_id': self.stack.id, 'nova_instance': self.resource_id, 'name': self.name, 'rsrc_metadata': self.metadata, 'stack_name': self.stack.name} new_rs = db_api.resource_create(self.context, rs) self.id = new_rs.id self.stack.updated_time = datetime.utcnow() except Exception as ex: logger.error('DB error %s' % str(ex)) def _add_event(self, new_state, reason): '''Add a state change event to the database.''' ev = event.Event(self.context, self.stack, self, new_state, reason, self.resource_id, self.properties) try: ev.store() except Exception as ex: logger.error('DB error %s' % str(ex)) def _store_or_update(self, new_state, reason): self.state = new_state self.state_description = reason if self.id is not None: try: rs = db_api.resource_get(self.context, self.id) rs.update_and_save({'state': self.state, 'state_description': reason, 'nova_instance': self.resource_id}) self.stack.updated_time = datetime.utcnow() except Exception as ex: logger.error('DB error %s' % str(ex)) # store resource in DB on transition to CREATE_IN_PROGRESS # all other transistions (other than to DELETE_COMPLETE) # should be handled by the update_and_save above.. elif new_state == self.CREATE_IN_PROGRESS: self._store() def state_set(self, new_state, reason="state changed"): old_state = self.state self._store_or_update(new_state, reason) if new_state != old_state: self._add_event(new_state, reason) def FnGetRefId(self): ''' http://docs.amazonwebservices.com/AWSCloudFormation/latest/UserGuide/\ intrinsic-function-reference-ref.html ''' if self.resource_id is not None: return unicode(self.resource_id) else: return unicode(self.name) def FnGetAtt(self, key): ''' http://docs.amazonwebservices.com/AWSCloudFormation/latest/UserGuide/\ intrinsic-function-reference-getatt.html ''' return unicode(self.name) def FnBase64(self, data): ''' http://docs.amazonwebservices.com/AWSCloudFormation/latest/UserGuide/\ intrinsic-function-reference-base64.html ''' return base64.b64encode(data) def handle_update(self, json_snippet=None, tmpl_diff=None, prop_diff=None): raise UpdateReplace(self.name) def metadata_update(self, new_metadata=None): ''' No-op for resources which don't explicitly override this method ''' if new_metadata: logger.warning("Resource %s does not implement metadata update" % self.name)