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Diffstat (limited to 'oslo_db/sqlalchemy/migration.py')
| -rw-r--r-- | oslo_db/sqlalchemy/migration.py | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/oslo_db/sqlalchemy/migration.py b/oslo_db/sqlalchemy/migration.py new file mode 100644 index 0000000..308ce60 --- /dev/null +++ b/oslo_db/sqlalchemy/migration.py @@ -0,0 +1,160 @@ +# coding=utf-8 + +# Copyright (c) 2013 OpenStack Foundation +# All Rights Reserved. +# +# 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. +# +# Base on code in migrate/changeset/databases/sqlite.py which is under +# the following license: +# +# The MIT License +# +# Copyright (c) 2009 Evan Rosson, Jan Dittberner, Domen Kožar +# +# Permission is hereby granted, free of charge, to any person obtaining a copy +# of this software and associated documentation files (the "Software"), to deal +# in the Software without restriction, including without limitation the rights +# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +# copies of the Software, and to permit persons to whom the Software is +# furnished to do so, subject to the following conditions: +# The above copyright notice and this permission notice shall be included in +# all copies or substantial portions of the Software. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +# THE SOFTWARE. + +import os + +from migrate import exceptions as versioning_exceptions +from migrate.versioning import api as versioning_api +from migrate.versioning.repository import Repository +import sqlalchemy + +from oslo_db._i18n import _ +from oslo_db import exception + + +def db_sync(engine, abs_path, version=None, init_version=0, sanity_check=True): + """Upgrade or downgrade a database. + + Function runs the upgrade() or downgrade() functions in change scripts. + + :param engine: SQLAlchemy engine instance for a given database + :param abs_path: Absolute path to migrate repository. + :param version: Database will upgrade/downgrade until this version. + If None - database will update to the latest + available version. + :param init_version: Initial database version + :param sanity_check: Require schema sanity checking for all tables + """ + + if version is not None: + try: + version = int(version) + except ValueError: + raise exception.DbMigrationError( + message=_("version should be an integer")) + + current_version = db_version(engine, abs_path, init_version) + repository = _find_migrate_repo(abs_path) + if sanity_check: + _db_schema_sanity_check(engine) + if version is None or version > current_version: + return versioning_api.upgrade(engine, repository, version) + else: + return versioning_api.downgrade(engine, repository, + version) + + +def _db_schema_sanity_check(engine): + """Ensure all database tables were created with required parameters. + + :param engine: SQLAlchemy engine instance for a given database + + """ + + if engine.name == 'mysql': + onlyutf8_sql = ('SELECT TABLE_NAME,TABLE_COLLATION ' + 'from information_schema.TABLES ' + 'where TABLE_SCHEMA=%s and ' + 'TABLE_COLLATION NOT LIKE \'%%utf8%%\'') + + # NOTE(morganfainberg): exclude the sqlalchemy-migrate and alembic + # versioning tables from the tables we need to verify utf8 status on. + # Non-standard table names are not supported. + EXCLUDED_TABLES = ['migrate_version', 'alembic_version'] + + table_names = [res[0] for res in + engine.execute(onlyutf8_sql, engine.url.database) if + res[0].lower() not in EXCLUDED_TABLES] + + if len(table_names) > 0: + raise ValueError(_('Tables "%s" have non utf8 collation, ' + 'please make sure all tables are CHARSET=utf8' + ) % ','.join(table_names)) + + +def db_version(engine, abs_path, init_version): + """Show the current version of the repository. + + :param engine: SQLAlchemy engine instance for a given database + :param abs_path: Absolute path to migrate repository + :param version: Initial database version + """ + repository = _find_migrate_repo(abs_path) + try: + return versioning_api.db_version(engine, repository) + except versioning_exceptions.DatabaseNotControlledError: + meta = sqlalchemy.MetaData() + meta.reflect(bind=engine) + tables = meta.tables + if len(tables) == 0 or 'alembic_version' in tables: + db_version_control(engine, abs_path, version=init_version) + return versioning_api.db_version(engine, repository) + else: + raise exception.DbMigrationError( + message=_( + "The database is not under version control, but has " + "tables. Please stamp the current version of the schema " + "manually.")) + + +def db_version_control(engine, abs_path, version=None): + """Mark a database as under this repository's version control. + + Once a database is under version control, schema changes should + only be done via change scripts in this repository. + + :param engine: SQLAlchemy engine instance for a given database + :param abs_path: Absolute path to migrate repository + :param version: Initial database version + """ + repository = _find_migrate_repo(abs_path) + versioning_api.version_control(engine, repository, version) + return version + + +def _find_migrate_repo(abs_path): + """Get the project's change script repository + + :param abs_path: Absolute path to migrate repository + """ + if not os.path.exists(abs_path): + raise exception.DbMigrationError("Path %s not found" % abs_path) + return Repository(abs_path) |