Source code for keystone.common.sql.core

# 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 functools

from oslo_db import exception as db_exception
from oslo_db import options as db_options
from oslo_db.sqlalchemy import enginefacade
from oslo_db.sqlalchemy import models
from oslo_log import log
from oslo_serialization import jsonutils
from osprofiler import opts as profiler
import osprofiler.sqlalchemy
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 driver_hints
from keystone.common import utils
import keystone.conf
from keystone import exception
from keystone.i18n import _


CONF = keystone.conf.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
Date = sql.Date
TIMESTAMP = sql.TIMESTAMP
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


[docs]def initialize(): """Initialize the module.""" db_options.set_defaults( CONF, connection="sqlite:///keystone.db") # Configure OSprofiler options profiler.set_defaults(CONF, enabled=False, trace_sqlalchemy=False)
[docs]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
[docs]class JsonBlob(sql_types.TypeDecorator): impl = sql.Text
[docs] def process_bind_param(self, value, dialect): return jsonutils.dumps(value)
[docs] def process_result_value(self, value, dialect): return jsonutils.loads(value)
[docs]class DictBase(models.ModelBase): attributes = [] @classmethod
[docs] def from_dict(cls, d): new_d = d.copy() new_d['extra'] = {k: new_d.pop(k) for k in d.keys() if k not in cls.attributes and k != 'extra'} return cls(**new_d)
[docs] def to_dict(self, include_extra_dict=False): """Return 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): """Evaluate if key is in extra or not, to return correct item.""" if key in self.extra: return self.extra[key] return getattr(self, key)
[docs]class ModelDictMixin(object): @classmethod
[docs] def from_dict(cls, d): """Return a model instance from a dictionary.""" return cls(**d)
[docs] def to_dict(self): """Return the model's attributes as a dictionary.""" names = (column.name for column in self.__table__.columns) return {name: getattr(self, name) for name in names}
_main_context_manager = None def _get_main_context_manager(): global _main_context_manager if not _main_context_manager: _main_context_manager = enginefacade.transaction_context() return _main_context_manager
[docs]def cleanup(): global _main_context_manager _main_context_manager = None
_CONTEXT = None def _get_context(): global _CONTEXT if _CONTEXT is None: # NOTE(dims): Delay the `threading.local` import to allow for # eventlet/gevent monkeypatching to happen import threading _CONTEXT = threading.local() return _CONTEXT # Unit tests set this to True so that oslo.db's global engine is used. # This allows oslo_db.test_base.DbTestCase to override the transaction manager # with its test transaction manager. _TESTING_USE_GLOBAL_CONTEXT_MANAGER = False
[docs]def session_for_read(): if _TESTING_USE_GLOBAL_CONTEXT_MANAGER: reader = enginefacade.reader else: reader = _get_main_context_manager().reader return _wrap_session(reader.using(_get_context()))
[docs]def session_for_write(): if _TESTING_USE_GLOBAL_CONTEXT_MANAGER: writer = enginefacade.writer else: writer = _get_main_context_manager().writer return _wrap_session(writer.using(_get_context()))
def _wrap_session(sess): if CONF.profiler.enabled and CONF.profiler.trace_sqlalchemy: sess = osprofiler.sqlalchemy.wrap_session(sql, sess) return sess
[docs]def truncated(f): return driver_hints.truncated(f)
class _WontMatch(Exception): """Raised to indicate that the filter won't match. This is raised to short-circuit the computation of the filter as soon as it's discovered that the filter requested isn't going to match anything. A filter isn't going to match anything if the value is too long for the field, for example. """ @classmethod def check(cls, value, col_attr): """Check if the value can match given the column attributes. Raises this class if the value provided can't match any value in the column in the table given the column's attributes. For example, if the column is a string and the value is longer than the column then it won't match any value in the column in the table. """ col = col_attr.property.columns[0] if isinstance(col.type, sql.types.Boolean): # The column is a Boolean, we should have already validated input. return if not col.type.length: # The column doesn't have a length so can't validate anymore. return if len(value) > col.type.length: raise cls() # Otherwise the value could match a value in the column. def _filter(model, query, hints): """Apply 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_, satisfied_filters): """Apply an inexact filter to a query. :param model: the table model in question :param query: query to apply filters to :param dict filter_: describes this filter :param list satisfied_filters: filter_ will be added if it is satisfied. :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': _WontMatch.check(filter_['value'], column_attr) query_term = column_attr.ilike('%%%s%%' % filter_['value']) elif filter_['comparator'] == 'startswith': _WontMatch.check(filter_['value'], column_attr) query_term = column_attr.ilike('%s%%' % filter_['value']) elif filter_['comparator'] == 'endswith': _WontMatch.check(filter_['value'], column_attr) 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 satisfied_filters.append(filter_) return query.filter(query_term) def exact_filter(model, query, filter_, satisfied_filters): """Apply an exact filter to a query. :param model: the table model in question :param query: query to apply filters to :param dict filter_: describes this filter :param list satisfied_filters: filter_ will be added if it is satisfied. :returns query: query updated to add any exact filters we could satisfy """ key = filter_['name'] col = getattr(model, key) if isinstance(col.property.columns[0].type, sql.types.Boolean): filter_val = utils.attr_as_boolean(filter_['value']) else: _WontMatch.check(filter_['value'], col) filter_val = filter_['value'] satisfied_filters.append(filter_) return query.filter(col == filter_val) try: satisfied_filters = [] for filter_ in hints.filters: if filter_['name'] not in model.attributes: continue if filter_['comparator'] == 'equals': query = exact_filter(model, query, filter_, satisfied_filters) else: query = inexact_filter(model, query, filter_, satisfied_filters) # Remove satisfied filters, then the caller will know remaining filters for filter_ in satisfied_filters: hints.filters.remove(filter_) return query except _WontMatch: hints.cannot_match = True return def _limit(query, hints): """Apply 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: original_len = query.count() limit_query = query.limit(hints.limit['limit']) if limit_query.count() < original_len: hints.limit['truncated'] = True query = limit_query return query
[docs]def filter_limit_query(model, query, hints): """Apply 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) if hints.cannot_match: # Nothing's going to match, so don't bother with the query. return [] # 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
[docs]def handle_conflicts(conflict_type='object'): """Convert 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)}) name = None field = None domain_id = None # First element is unnessecary for extracting name and causes # object not iterable error. Remove it. params = args[1:] # We want to store the duplicate objects name in the error # message for the user. If name is not available we use the id. for arg in params: if 'name' in arg: field = 'name' name = arg['name'] elif 'id' in arg: field = 'ID' name = arg['id'] if 'domain_id' in arg: domain_id = arg['domain_id'] msg = _('Duplicate entry') if name and domain_id: msg = _('Duplicate entry found with %(field)s %(name)s ' 'at domain ID %(domain_id)s') % { 'field': field, 'name': name, 'domain_id': domain_id} elif name: msg = _('Duplicate entry found with %(field)s ' '%(name)s') % {'field': field, 'name': name} elif domain_id: msg = (_('Duplicate entry at domain ID %s') % domain_id) raise exception.Conflict(type=conflict_type, details=msg) 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