ironic.objects.base

Source code for ironic.objects.base

#    Copyright 2013 IBM Corp.
#
#    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
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#    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
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"""Ironic common internal object model"""

from oslo_log import log
from oslo_utils import versionutils
from oslo_versionedobjects import base as object_base
from oslo_versionedobjects import exception as ovo_exception

from ironic.common import release_mappings as versions
from ironic.conf import CONF
from ironic import objects
from ironic.objects import fields as object_fields

LOG = log.getLogger(__name__)


[docs]class IronicObjectRegistry(object_base.VersionedObjectRegistry):
[docs] def registration_hook(self, cls, index): # NOTE(jroll): blatantly stolen from nova # NOTE(danms): This is called when an object is registered, # and is responsible for maintaining ironic.objects.$OBJECT # as the highest-versioned implementation of a given object. version = versionutils.convert_version_to_tuple(cls.VERSION) if not hasattr(objects, cls.obj_name()): setattr(objects, cls.obj_name(), cls) else: cur_version = versionutils.convert_version_to_tuple( getattr(objects, cls.obj_name()).VERSION) if version >= cur_version: setattr(objects, cls.obj_name(), cls)
[docs]class IronicObject(object_base.VersionedObject): """Base class and object factory. This forms the base of all objects that can be remoted or instantiated via RPC. Simply defining a class that inherits from this base class will make it remotely instantiatable. Objects should implement the necessary "get" classmethod routines as well as "save" object methods as appropriate. """ OBJ_SERIAL_NAMESPACE = 'ironic_object' OBJ_PROJECT_NAMESPACE = 'ironic' # TODO(lintan) Refactor these fields and create PersistentObject and # TimeStampObject like Nova when it is necessary. fields = { 'created_at': object_fields.DateTimeField(nullable=True), 'updated_at': object_fields.DateTimeField(nullable=True), }
[docs] def as_dict(self): """Return the object represented as a dict. The returned object is JSON-serialisable. """ def _attr_as_dict(field): """Return an attribute as a dict, handling nested objects.""" attr = getattr(self, field) if isinstance(attr, IronicObject): attr = attr.as_dict() return attr return dict((k, _attr_as_dict(k)) for k in self.fields if self.obj_attr_is_set(k))
[docs] def obj_refresh(self, loaded_object): """Applies updates for objects that inherit from base.IronicObject. Checks for updated attributes in an object. Updates are applied from the loaded object column by column in comparison with the current object. """ for field in self.fields: if (self.obj_attr_is_set(field) and self[field] != loaded_object[field]): self[field] = loaded_object[field]
def _convert_to_version(self, target_version, remove_unavailable_fields=True): """Convert to the target version. Subclasses should redefine this method, to do the conversion of the object to the target version. Convert the object to the target version. The target version may be the same, older, or newer than the version of the object. This is used for DB interactions as well as for serialization/deserialization. The remove_unavailable_fields flag is used to distinguish these two cases: 1) For serialization/deserialization, we need to remove the unavailable fields, because the service receiving the object may not know about these fields. remove_unavailable_fields is set to True in this case. 2) For DB interactions, we need to set the unavailable fields to their appropriate values so that these fields are saved in the DB. (If they are not set, the VersionedObject magic will not know to save/update them to the DB.) remove_unavailable_fields is set to False in this case. :param target_version: the desired version of the object :param remove_unavailable_fields: True to remove fields that are unavailable in the target version; set this to True when (de)serializing. False to set the unavailable fields to appropriate values; set this to False for DB interactions. """ pass
[docs] def convert_to_version(self, target_version, remove_unavailable_fields=True): """Convert this object to the target version. Convert the object to the target version. The target version may be the same, older, or newer than the version of the object. This is used for DB interactions as well as for serialization/deserialization. The remove_unavailable_fields flag is used to distinguish these two cases: 1) For serialization/deserialization, we need to remove the unavailable fields, because the service receiving the object may not know about these fields. remove_unavailable_fields is set to True in this case. 2) For DB interactions, we need to set the unavailable fields to their appropriate values so that these fields are saved in the DB. (If they are not set, the VersionedObject magic will not know to save/update them to the DB.) remove_unavailable_fields is set to False in this case. _convert_to_version() does the actual work. :param target_version: the desired version of the object :param remove_unavailable_fields: True to remove fields that are unavailable in the target version; set this to True when (de)serializing. False to set the unavailable fields to appropriate values; set this to False for DB interactions. """ if self.VERSION != target_version: self._convert_to_version( target_version, remove_unavailable_fields=remove_unavailable_fields) if remove_unavailable_fields: # NOTE(rloo): We changed the object, but don't keep track of # any of these changes, since it is inaccurate anyway (because # it doesn't keep track of any 'changed' unavailable fields). self.obj_reset_changes() # NOTE(rloo): self.__class__.VERSION is the latest version that # is supported by this service. self.VERSION is the version of # this object instance -- it may get set via e.g. the # serialization or deserialization process, or here. if (self.__class__.VERSION != target_version or self.VERSION != self.__class__.VERSION): self.VERSION = target_version
[docs] @classmethod def get_target_version(cls): """Returns the target version for this object. This is the version in which the object should be manipulated, e.g. sent over the wire via RPC or saved in the DB. :returns: if pinned, returns the version of this object corresponding to the pin. Otherwise, returns the version of the object. :raises: ovo_exception.IncompatibleObjectVersion """ pin = CONF.pin_release_version if not pin: return cls.VERSION version_manifest = versions.RELEASE_MAPPING[pin]['objects'] pinned_version = version_manifest.get(cls.obj_name()) if pinned_version: pinned_version = pinned_version[0] if not versionutils.is_compatible(pinned_version, cls.VERSION): LOG.error( 'For object "%(objname)s", the target version ' '"%(target)s" is not compatible with its supported ' 'version "%(support)s". The value ("%(pin)s") of the ' '"pin_release_version" configuration option may be ' 'incorrect.', {'objname': cls.obj_name(), 'target': pinned_version, 'support': cls.VERSION, 'pin': pin}) raise ovo_exception.IncompatibleObjectVersion( objname=cls.obj_name(), objver=pinned_version, supported=cls.VERSION) return pinned_version return cls.VERSION
[docs] @classmethod def supports_version(cls, version): """Return whether this object supports a particular version. Check the requested version against the object's target version. The target version may not be the latest version during an upgrade, when object versions are pinned. :param version: A tuple representing the version to check :returns: Whether the version is supported :raises: ovo_exception.IncompatibleObjectVersion """ target_version = cls.get_target_version() target_version = versionutils.convert_version_to_tuple(target_version) return target_version >= version
def _set_from_db_object(self, context, db_object, fields=None): """Sets object fields. :param context: security context :param db_object: A DB entity of the object :param fields: list of fields to set on obj from values from db_object. """ fields = fields or self.fields for field in fields: setattr(self, field, db_object[field]) @staticmethod def _from_db_object(context, obj, db_object, fields=None): """Converts a database entity to a formal object. This always converts the database entity to the latest version of the object. Note that the latest version is available at object.__class__.VERSION. object.VERSION is the version of this particular object instance; it is possible that it is not the latest version. :param context: security context :param obj: An object of the class. :param db_object: A DB entity of the object :param fields: list of fields to set on obj from values from db_object. :return: The object of the class with the database entity added :raises: ovo_exception.IncompatibleObjectVersion """ objname = obj.obj_name() db_version = db_object['version'] if db_version is None: # NOTE(rloo): This can only happen if the DB is corrupt or this # is the conductor object. (Because the rest of the objects will # all have their DB version set properly.) # TODO(rloo): This entire if clause can be deleted in Rocky # since the dbsync online migration populates all the conductor # versions and it must be run to completion before upgrading to # Rocky. db_version = versions.RELEASE_MAPPING['pike']['objects'].get( objname, ['1.0'])[0] if not versionutils.is_compatible(db_version, obj.__class__.VERSION): raise ovo_exception.IncompatibleObjectVersion( objname=objname, objver=db_version, supported=obj.__class__.VERSION) obj._set_from_db_object(context, db_object, fields) obj._context = context # NOTE(rloo). We now have obj, a versioned object that corresponds to # its DB representation. A versioned object has an internal attribute # ._changed_fields; this is a list of changed fields -- used, e.g., # when saving the object to the DB (only those changed fields are # saved to the DB). The obj.obj_reset_changes() clears this list # since we didn't actually make any modifications to the object that # we want saved later. obj.obj_reset_changes() if db_version != obj.__class__.VERSION: # convert to the latest version obj.VERSION = db_version obj.convert_to_version(obj.__class__.VERSION, remove_unavailable_fields=False) return obj @classmethod def _from_db_object_list(cls, context, db_objects): """Returns objects corresponding to database entities. Returns a list of formal objects of this class that correspond to the list of database entities. :param cls: the VersionedObject class of the desired object :param context: security context :param db_objects: A list of DB models of the object :returns: A list of objects corresponding to the database entities """ return [cls._from_db_object(context, cls(), db_obj) for db_obj in db_objects]
[docs] def do_version_changes_for_db(self): """Change the object to the version needed for the database. If needed, this changes the object (modifies object fields) to be in the correct version for saving to the database. The version used to save the object in the DB is determined as follows: * If the object is pinned, we save the object in the pinned version. Since it is pinned, we must not save in a newer version, in case a rolling upgrade is happening and some services are still using the older version of ironic, with no knowledge of this newer version. * If the object isn't pinned, we save the object in the latest version. Because the object may be converted to a different object version, this method must only be called just before saving the object to the DB. :returns: a dictionary of changed fields and their new values (could be an empty dictionary). These are the fields/values of the object that would be saved to the DB. """ target_version = self.get_target_version() if target_version != self.VERSION: # Convert the object so we can save it in the target version. self.convert_to_version(target_version, remove_unavailable_fields=False) changes = self.obj_get_changes() # NOTE(rloo): Since this object doesn't keep track of the version that # is saved in the DB and we don't want to make a DB call # just to find out, we always update 'version' in the DB. changes['version'] = self.VERSION return changes
[docs]class IronicObjectListBase(object_base.ObjectListBase):
[docs] def as_dict(self): """Return the object represented as a dict. The returned object is JSON-serialisable. """ return {'objects': [obj.as_dict() for obj in self.objects]}
[docs]class IronicObjectSerializer(object_base.VersionedObjectSerializer): # Base class to use for object hydration OBJ_BASE_CLASS = IronicObject def __init__(self, is_server=False): """Initialization. :param is_server: True if the service using this Serializer is a server (i.e. an ironic-conductor). Default is False for clients (such as ironic-api). """ super(IronicObjectSerializer, self).__init__() self.is_server = is_server def _process_object(self, context, objprim): """Process the object. This is called from within deserialize_entity(). Deserialization is done for any serialized entities from e.g. an RPC request; the deserialization process converts them to Objects. This converts any IronicObjects to be in their latest versions, so that internally, the services (ironic-api and ironic-conductor) always deal with objects in their latest versions. :param objprim: a serialized entity that represents an object :returns: the deserialized Object :raises ovo_exception.IncompatibleObjectVersion """ obj = super(IronicObjectSerializer, self)._process_object( context, objprim) if isinstance(obj, IronicObject): if obj.VERSION != obj.__class__.VERSION: # NOTE(rloo): if deserializing at API (client) side, # we don't want any changes obj.convert_to_version( obj.__class__.VERSION, remove_unavailable_fields=not self.is_server) return obj
[docs] def serialize_entity(self, context, entity): """Serialize the entity. This serializes the entity so that it can be sent over e.g. RPC. A serialized entity for an IronicObject is a dictionary with keys: 'ironic_object.namespace', 'ironic_object.data', 'ironic_object.name', 'ironic_object.version', and 'ironic_object.changes'. We assume that the client (ironic-API) is always talking to a server (ironic-conductor) that is running the same or a newer release than the client. The client doesn't need to downgrade any IronicObjects when sending them over RPC. The server, on the other hand, will need to do so if the server is pinned and the target version of an IronicObject is older than the latest version of that Object. (Internally, the services deal with the latest versions of objects so we know that these objects are always in the latest versions.) :param context: security context :param entity: the entity to be serialized; may be an IronicObject :returns: the serialized entity :raises: ovo_exception.IncompatibleObjectVersion (via .get_target_version()) """ if self.is_server and isinstance(entity, IronicObject): target_version = entity.get_target_version() if target_version != entity.VERSION: # NOTE(xek): If the version is pinned, target_version is an # older object version. We need to backport/convert to target # version before serialization. entity.convert_to_version(target_version, remove_unavailable_fields=True) return super(IronicObjectSerializer, self).serialize_entity( context, entity)
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