# Copyright 2012 OpenStack Foundation # # 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. """SQL backends for the various services. Before using this module, call initialize(). This has to be done before CONF() because it sets up configuration options. """ import contextlib import functools from oslo_config import cfg from oslo_db import exception as db_exception from oslo_db import options as db_options from oslo_db.sqlalchemy import models from oslo_db.sqlalchemy import session as db_session from oslo_log import log from oslo_serialization import jsonutils import six import sqlalchemy as sql from sqlalchemy.ext import declarative from sqlalchemy.orm.attributes import flag_modified, InstrumentedAttribute from sqlalchemy import types as sql_types from keystone.common import utils from keystone import exception from keystone.i18n import _ CONF = cfg.CONF LOG = log.getLogger(__name__) ModelBase = declarative.declarative_base() # For exporting to other modules Column = sql.Column Index = sql.Index String = sql.String Integer = sql.Integer Enum = sql.Enum ForeignKey = sql.ForeignKey DateTime = sql.DateTime IntegrityError = sql.exc.IntegrityError DBDuplicateEntry = db_exception.DBDuplicateEntry OperationalError = sql.exc.OperationalError NotFound = sql.orm.exc.NoResultFound Boolean = sql.Boolean Text = sql.Text UniqueConstraint = sql.UniqueConstraint PrimaryKeyConstraint = sql.PrimaryKeyConstraint joinedload = sql.orm.joinedload # Suppress flake8's unused import warning for flag_modified: flag_modified = flag_modified def initialize(): """Initialize the module.""" db_options.set_defaults( CONF, connection="sqlite:///keystone.db") def initialize_decorator(init): """Ensure that the length of string field do not exceed the limit. This decorator check the initialize arguments, to make sure the length of string field do not exceed the length limit, or raise a 'StringLengthExceeded' exception. Use decorator instead of inheritance, because the metaclass will check the __tablename__, primary key columns, etc. at the class definition. """ def initialize(self, *args, **kwargs): cls = type(self) for k, v in kwargs.items(): if hasattr(cls, k): attr = getattr(cls, k) if isinstance(attr, InstrumentedAttribute): column = attr.property.columns[0] if isinstance(column.type, String): if not isinstance(v, six.text_type): v = six.text_type(v) if column.type.length and column.type.length < len(v): raise exception.StringLengthExceeded( string=v, type=k, length=column.type.length) init(self, *args, **kwargs) return initialize ModelBase.__init__ = initialize_decorator(ModelBase.__init__) # Special Fields class JsonBlob(sql_types.TypeDecorator): impl = sql.Text def process_bind_param(self, value, dialect): return jsonutils.dumps(value) def process_result_value(self, value, dialect): return jsonutils.loads(value) class DictBase(models.ModelBase): attributes = [] @classmethod def from_dict(cls, d): new_d = d.copy() new_d['extra'] = dict((k, new_d.pop(k)) for k in six.iterkeys(d) if k not in cls.attributes and k != 'extra') return cls(**new_d) def to_dict(self, include_extra_dict=False): """Returns the model's attributes as a dictionary. If include_extra_dict is True, 'extra' attributes are literally included in the resulting dictionary twice, for backwards-compatibility with a broken implementation. """ d = self.extra.copy() for attr in self.__class__.attributes: d[attr] = getattr(self, attr) if include_extra_dict: d['extra'] = self.extra.copy() return d def __getitem__(self, key): if key in self.extra: return self.extra[key] return getattr(self, key) class ModelDictMixin(object): @classmethod def from_dict(cls, d): """Returns a model instance from a dictionary.""" return cls(**d) def to_dict(self): """Returns the model's attributes as a dictionary.""" names = (column.name for column in self.__table__.columns) return dict((name, getattr(self, name)) for name in names) _engine_facade = None def _get_engine_facade(): global _engine_facade if not _engine_facade: _engine_facade = db_session.EngineFacade.from_config(CONF) return _engine_facade def cleanup(): global _engine_facade _engine_facade = None def get_engine(): return _get_engine_facade().get_engine() def get_session(expire_on_commit=False): return _get_engine_facade().get_session(expire_on_commit=expire_on_commit) @contextlib.contextmanager def transaction(expire_on_commit=False): """Return a SQLAlchemy session in a scoped transaction.""" session = get_session(expire_on_commit=expire_on_commit) with session.begin(): yield session def truncated(f): """Ensure list truncation is detected in Driver list entity methods. This is designed to wrap and sql Driver list_{entity} methods in order to calculate if the resultant list has been truncated. Provided a limit dict is found in the hints list, we increment the limit by one so as to ask the wrapped function for one more entity than the limit, and then once the list has been generated, we check to see if the original limit has been exceeded, in which case we truncate back to that limit and set the 'truncated' boolean to 'true' in the hints limit dict. """ @functools.wraps(f) def wrapper(self, hints, *args, **kwargs): if not hasattr(hints, 'limit'): raise exception.UnexpectedError( _('Cannot truncate a driver call without hints list as ' 'first parameter after self ')) if hints.limit is None: return f(self, hints, *args, **kwargs) # A limit is set, so ask for one more entry than we need list_limit = hints.limit['limit'] hints.set_limit(list_limit + 1) ref_list = f(self, hints, *args, **kwargs) # If we got more than the original limit then trim back the list and # mark it truncated. In both cases, make sure we set the limit back # to its original value. if len(ref_list) > list_limit: hints.set_limit(list_limit, truncated=True) return ref_list[:list_limit] else: hints.set_limit(list_limit) return ref_list return wrapper def _filter(model, query, hints): """Applies filtering to a query. :param model: the table model in question :param query: query to apply filters to :param hints: contains the list of filters yet to be satisfied. Any filters satisfied here will be removed so that the caller will know if any filters remain. :returns query: query, updated with any filters satisfied """ def inexact_filter(model, query, filter_, hints): """Applies an inexact filter to a query. :param model: the table model in question :param query: query to apply filters to :param filter_: the dict that describes this filter :param hints: contains the list of filters yet to be satisfied. Any filters satisfied here will be removed so that the caller will know if any filters remain. :returns query: query updated to add any inexact filters we could satisfy """ column_attr = getattr(model, filter_['name']) # TODO(henry-nash): Sqlalchemy 0.7 defaults to case insensitivity # so once we find a way of changing that (maybe on a call-by-call # basis), we can add support for the case sensitive versions of # the filters below. For now, these case sensitive versions will # be handled at the controller level. if filter_['case_sensitive']: return query if filter_['comparator'] == 'contains': query_term = column_attr.ilike('%%%s%%' % filter_['value']) elif filter_['comparator'] == 'startswith': query_term = column_attr.ilike('%s%%' % filter_['value']) elif filter_['comparator'] == 'endswith': query_term = column_attr.ilike('%%%s' % filter_['value']) else: # It's a filter we don't understand, so let the caller # work out if they need to do something with it. return query hints.filters.remove(filter_) return query.filter(query_term) def exact_filter(model, filter_, cumulative_filter_dict, hints): """Applies an exact filter to a query. :param model: the table model in question :param filter_: the dict that describes this filter :param cumulative_filter_dict: a dict that describes the set of exact filters built up so far :param hints: contains the list of filters yet to be satisfied. Any filters satisfied here will be removed so that the caller will know if any filters remain. :returns: updated cumulative dict """ key = filter_['name'] if isinstance(getattr(model, key).property.columns[0].type, sql.types.Boolean): cumulative_filter_dict[key] = ( utils.attr_as_boolean(filter_['value'])) else: cumulative_filter_dict[key] = filter_['value'] hints.filters.remove(filter_) return cumulative_filter_dict filter_dict = {} for filter_ in hints.filters: if filter_['name'] not in model.attributes: continue if filter_['comparator'] == 'equals': filter_dict = exact_filter(model, filter_, filter_dict, hints) else: query = inexact_filter(model, query, filter_, hints) # Apply any exact filters we built up if filter_dict: query = query.filter_by(**filter_dict) return query def _limit(query, hints): """Applies a limit to a query. :param query: query to apply filters to :param hints: contains the list of filters and limit details. :returns updated query """ # NOTE(henry-nash): If we were to implement pagination, then we # we would expand this method to support pagination and limiting. # If we satisfied all the filters, set an upper limit if supplied if hints.limit: query = query.limit(hints.limit['limit']) return query def filter_limit_query(model, query, hints): """Applies filtering and limit to a query. :param model: table model :param query: query to apply filters to :param hints: contains the list of filters and limit details. This may be None, indicating that there are no filters or limits to be applied. If it's not None, then any filters satisfied here will be removed so that the caller will know if any filters remain. :returns: updated query """ if hints is None: return query # First try and satisfy any filters query = _filter(model, query, hints) # NOTE(henry-nash): Any unsatisfied filters will have been left in # the hints list for the controller to handle. We can only try and # limit here if all the filters are already satisfied since, if not, # doing so might mess up the final results. If there are still # unsatisfied filters, we have to leave any limiting to the controller # as well. if not hints.filters: return _limit(query, hints) else: return query def handle_conflicts(conflict_type='object'): """Converts select sqlalchemy exceptions into HTTP 409 Conflict.""" _conflict_msg = 'Conflict %(conflict_type)s: %(details)s' def decorator(method): @functools.wraps(method) def wrapper(*args, **kwargs): try: return method(*args, **kwargs) except db_exception.DBDuplicateEntry as e: # LOG the exception for debug purposes, do not send the # exception details out with the raised Conflict exception # as it can contain raw SQL. LOG.debug(_conflict_msg, {'conflict_type': conflict_type, 'details': six.text_type(e)}) raise exception.Conflict(type=conflict_type, details=_('Duplicate Entry')) except db_exception.DBError as e: # TODO(blk-u): inspecting inner_exception breaks encapsulation; # oslo_db should provide exception we need. if isinstance(e.inner_exception, IntegrityError): # LOG the exception for debug purposes, do not send the # exception details out with the raised Conflict exception # as it can contain raw SQL. LOG.debug(_conflict_msg, {'conflict_type': conflict_type, 'details': six.text_type(e)}) # NOTE(morganfainberg): This is really a case where the SQL # failed to store the data. This is not something that the # user has done wrong. Example would be a ForeignKey is # missing; the code that is executed before reaching the # SQL writing to the DB should catch the issue. raise exception.UnexpectedError( _('An unexpected error occurred when trying to ' 'store %s') % conflict_type) raise return wrapper return decorator