alembic with initial migration and tests

All sqlalchemy migrations and code associated
with them was removed including tests

Added all necessery alembic code to expose alembic specific features:
like revision and stamp

Added initial migration for alembic, that is fully in sync with models
including: uniques, indexes and columns params

Refactored test_versions to use alembic as migration api

Refactored BaseTestCase and Database fixture to use alembic as migration api

Change-Id: I8a91704d21ccea1b8135b9d724df5856ac21108c

ironic/cmd/dbsync.py

@@ -24,10 +24,74 @@ Run storage database migration.
 
 import sys
 
+from oslo.config import cfg
+
 from ironic.common import service
 from ironic.db import migration
 
 
+CONF = cfg.CONF
+
+
+class DBCommand(object):
+
+    def upgrade(self):
+        migration.upgrade(CONF.command.revision)
+
+    def downgrade(self):
+        migration.downgrade(CONF.command.revision)
+
+    def revision(self):
+        migration.revision(CONF.command.message, CONF.command.autogenerate)
+
+    def stamp(self):
+        migration.stamp(CONF.command.revision)
+
+    def version(self):
+        print(migration.version())
+
+
+def add_command_parsers(subparsers):
+    command_object = DBCommand()
+
+    parser = subparsers.add_parser('upgrade')
+    parser.set_defaults(func=command_object.upgrade)
+    parser.add_argument('--revision', nargs='?')
+
+    parser = subparsers.add_parser('downgrade')
+    parser.set_defaults(func=command_object.downgrade)
+    parser.add_argument('--revision', nargs='?')
+
+    parser = subparsers.add_parser('stamp')
+    parser.add_argument('--revision', nargs='?')
+    parser.set_defaults(func=command_object.stamp)
+
+    parser = subparsers.add_parser('revision')
+    parser.add_argument('-m', '--message')
+    parser.add_argument('--autogenerate', action='store_true')
+    parser.set_defaults(func=command_object.revision)
+
+    parser = subparsers.add_parser('version')
+    parser.set_defaults(func=command_object.version)
+
+
+command_opt = cfg.SubCommandOpt('command',
+                                title='Command',
+                                help='Available commands',
+                                handler=add_command_parsers)
+
+CONF.register_cli_opt(command_opt)
+
+
 def main():
+    # this is hack to work with previous usage of ironic-dbsync
+    # pls change it to ironic-dbsync upgrade
+    valid_commands = set([
+        'upgrade', 'downgrade', 'revision',
+        'version', 'stamp'
+    ])
+    if not set(sys.argv) & valid_commands:
+        sys.argv.append('upgrade')
+
     service.prepare_service(sys.argv)
-    migration.db_sync()
+    CONF.command.func()

ironic/db/migration.py

@@ -28,18 +28,29 @@ CONF.import_opt('backend',
                 group='database')
 
 IMPL = utils.LazyPluggable(
-        pivot='backend',
-        config_group='database',
-        sqlalchemy='ironic.db.sqlalchemy.migration')
+    pivot='backend',
+    config_group='database',
+    sqlalchemy='ironic.db.sqlalchemy.migration')
 
 INIT_VERSION = 0
 
 
-def db_sync(version=None):
+def upgrade(version=None):
     """Migrate the database to `version` or the most recent version."""
-    return IMPL.db_sync(version=version)
+    return IMPL.upgrade(version)
 
 
-def db_version():
-    """Display the current database version."""
-    return IMPL.db_version()
+def downgrade(version=None):
+    return IMPL.downgrade(version)
+
+
+def version():
+    return IMPL.version()
+
+
+def stamp(version):
+    return IMPL.stamp(version)
+
+
+def revision(message, autogenerate):
+    return IMPL.revision(message, autogenerate)

ironic/db/sqlalchemy/alembic.ini

@@ -0,0 +1,54 @@
+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts
+script_location = %(here)s/alembic
+
+# template used to generate migration files
+# file_template = %%(rev)s_%%(slug)s
+
+# max length of characters to apply to the
+# "slug" field
+#truncate_slug_length = 40
+
+# set to 'true' to run the environment during
+# the 'revision' command, regardless of autogenerate
+# revision_environment = false
+
+#sqlalchemy.url = driver://user:pass@localhost/dbname
+
+
+# Logging configuration
+[loggers]
+keys = root,sqlalchemy,alembic
+
+[handlers]
+keys = console
+
+[formatters]
+keys = generic
+
+[logger_root]
+level = WARN
+handlers = console
+qualname =
+
+[logger_sqlalchemy]
+level = WARN
+handlers =
+qualname = sqlalchemy.engine
+
+[logger_alembic]
+level = INFO
+handlers =
+qualname = alembic
+
+[handler_console]
+class = StreamHandler
+args = (sys.stderr,)
+level = NOTSET
+formatter = generic
+
+[formatter_generic]
+format = %(levelname)-5.5s [%(name)s] %(message)s
+datefmt = %H:%M:%S

ironic/db/sqlalchemy/alembic/README

@@ -0,0 +1,16 @@
+Please see https://alembic.readthedocs.org/en/latest/index.html for general documentation
+
+To create alembic migrations use:
+$ ironic-dbsync revision --message --autogenerate
+
+Stamp db with most recent migration version, without actually running migrations
+$ ironic-dbsync stamp --revision head
+
+Upgrade can be performed by:
+$ ironic-dbsync - for backward compatibility
+$ ironic-dbsync upgrade
+# ironic-dbsync upgrade --revision head
+
+Downgrading db:
+$ ironic-dbsync downgrade
+$ ironic-dbsync downgrade --revision base

ironic/db/sqlalchemy/alembic/env.py

@@ -0,0 +1,54 @@
+#    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.
+
+from logging import config as log_config
+
+from alembic import context
+
+from ironic.db.sqlalchemy import models
+import ironic.openstack.common.db.sqlalchemy.session as sqlalchemy_session
+
+# this is the Alembic Config object, which provides
+# access to the values within the .ini file in use.
+config = context.config
+
+# Interpret the config file for Python logging.
+# This line sets up loggers basically.
+log_config.fileConfig(config.config_file_name)
+
+# add your model's MetaData object here
+# for 'autogenerate' support
+# from myapp import mymodel
+target_metadata = models.Base.metadata
+
+# other values from the config, defined by the needs of env.py,
+# can be acquired:
+# my_important_option = config.get_main_option("my_important_option")
+# ... etc.
+
+
+def run_migrations_online():
+    """Run migrations in 'online' mode.
+
+    In this scenario we need to create an Engine
+    and associate a connection with the context.
+
+    """
+    engine = sqlalchemy_session.get_engine()
+    with engine.connect() as connection:
+        context.configure(connection=connection,
+                          target_metadata=target_metadata)
+        with context.begin_transaction():
+            context.run_migrations()
+
+
+run_migrations_online()

ironic/db/sqlalchemy/alembic/script.py.mako

@@ -0,0 +1,22 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision}
+Create Date: ${create_date}
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = ${repr(up_revision)}
+down_revision = ${repr(down_revision)}
+
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+def upgrade():
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade():
+    ${downgrades if downgrades else "pass"}

ironic/db/sqlalchemy/alembic/versions/2581ebaf0cb2_initial_migration.py

@@ -0,0 +1,106 @@
+#
+#    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.
+
+"""initial migration
+
+Revision ID: 2581ebaf0cb2
+Revises: None
+Create Date: 2014-01-17 12:14:07.754448
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '2581ebaf0cb2'
+down_revision = None
+
+from alembic import op
+import sqlalchemy as sa
+
+
+def upgrade():
+    ### commands auto generated by Alembic - please adjust! ###
+    op.create_table(
+        'conductors',
+        sa.Column('created_at', sa.DateTime(), nullable=True),
+        sa.Column('updated_at', sa.DateTime(), nullable=True),
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('hostname', sa.String(length=255), nullable=False),
+        sa.Column('drivers', sa.Text(), nullable=True),
+        sa.PrimaryKeyConstraint('id'),
+        sa.UniqueConstraint('hostname', name='uniq_conductors0hostname'),
+        mysql_ENGINE='InnoDB',
+        mysql_DEFAULT_CHARSET='UTF8'
+    )
+    op.create_table(
+        'chassis',
+        sa.Column('created_at', sa.DateTime(), nullable=True),
+        sa.Column('updated_at', sa.DateTime(), nullable=True),
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('uuid', sa.String(length=36), nullable=True),
+        sa.Column('extra', sa.Text(), nullable=True),
+        sa.Column('description', sa.String(length=255), nullable=True),
+        sa.PrimaryKeyConstraint('id'),
+        sa.UniqueConstraint('uuid', name='uniq_chassis0uuid'),
+        mysql_ENGINE='InnoDB',
+        mysql_DEFAULT_CHARSET='UTF8'
+    )
+    op.create_table(
+        'nodes',
+        sa.Column('created_at', sa.DateTime(), nullable=True),
+        sa.Column('updated_at', sa.DateTime(), nullable=True),
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('uuid', sa.String(length=36), nullable=True),
+        sa.Column('instance_uuid', sa.String(length=36), nullable=True),
+        sa.Column('chassis_id', sa.Integer(), nullable=True),
+        sa.Column('power_state', sa.String(length=15), nullable=True),
+        sa.Column('target_power_state', sa.String(length=15), nullable=True),
+        sa.Column('provision_state', sa.String(length=15), nullable=True),
+        sa.Column('target_provision_state', sa.String(length=15),
+                  nullable=True),
+        sa.Column('last_error', sa.Text(), nullable=True),
+        sa.Column('properties', sa.Text(), nullable=True),
+        sa.Column('driver', sa.String(length=15), nullable=True),
+        sa.Column('driver_info', sa.Text(), nullable=True),
+        sa.Column('reservation', sa.String(length=255), nullable=True),
+        sa.Column('maintenance', sa.Boolean(), nullable=True),
+        sa.Column('extra', sa.Text(), nullable=True),
+        sa.ForeignKeyConstraint(['chassis_id'], ['chassis.id'], ),
+        sa.PrimaryKeyConstraint('id'),
+        sa.UniqueConstraint('uuid', name='uniq_nodes0uuid'),
+        mysql_ENGINE='InnoDB',
+        mysql_DEFAULT_CHARSET='UTF8'
+    )
+    op.create_index('node_instance_uuid', 'nodes', ['instance_uuid'],
+                    unique=False)
+    op.create_table(
+        'ports',
+        sa.Column('created_at', sa.DateTime(), nullable=True),
+        sa.Column('updated_at', sa.DateTime(), nullable=True),
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('uuid', sa.String(length=36), nullable=True),
+        sa.Column('address', sa.String(length=18), nullable=True),
+        sa.Column('node_id', sa.Integer(), nullable=True),
+        sa.Column('extra', sa.Text(), nullable=True),
+        sa.ForeignKeyConstraint(['node_id'], ['nodes.id'], ),
+        sa.PrimaryKeyConstraint('id'),
+        sa.UniqueConstraint('address', name='uniq_ports0address'),
+        sa.UniqueConstraint('uuid', name='uniq_ports0uuid'),
+        mysql_ENGINE='InnoDB',
+        mysql_DEFAULT_CHARSET='UTF8'
+    )
+    ### end Alembic commands ###
+
+
+def downgrade():
+    raise NotImplementedError(('Downgrade from initial migration is'
+                              ' unsupported.'))

ironic/db/sqlalchemy/migrate_repo/manage.py

@@ -1,22 +0,0 @@
-# vim: tabstop=4 shiftwidth=4 softtabstop=4
-# -*- encoding: utf-8 -*-
-#
-# Copyright 2013 Hewlett-Packard Development Company, L.P.
-#
-#    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.
-
-from migrate.versioning.shell import main
-
-
-if __name__ == '__main__':
-    main(debug='False', repository='.')

ironic/db/sqlalchemy/migrate_repo/migrate.cfg

@@ -1,20 +0,0 @@
-[db_settings]
-# Used to identify which repository this database is versioned under.
-# You can use the name of your project.
-repository_id=ironic
-
-# The name of the database table used to track the schema version.
-# This name shouldn't already be used by your project.
-# If this is changed once a database is under version control, you'll need to
-# change the table name in each database too.
-version_table=migrate_version
-
-# When committing a change script, Migrate will attempt to generate the
-# sql for all supported databases; normally, if one of them fails - probably
-# because you don't have that database installed - it is ignored and the
-# commit continues, perhaps ending successfully.
-# Databases in this list MUST compile successfully during a commit, or the
-# entire commit will fail. List the databases your application will actually
-# be using to ensure your updates to that database work properly.
-# This must be a list; example: ['postgres','sqlite']
-required_dbs=[]

ironic/db/sqlalchemy/migrate_repo/versions/001_init.py

@@ -1,96 +0,0 @@
-# vim: tabstop=4 shiftwidth=4 softtabstop=4
-# -*- encoding: utf-8 -*-
-#
-# Copyright 2013 Hewlett-Packard Development Company, L.P.
-#
-#    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.
-
-
-from migrate.changeset import UniqueConstraint
-from sqlalchemy import Table, Column, Index, ForeignKey, MetaData
-from sqlalchemy import DateTime, Integer, String, Text
-
-from ironic.openstack.common import log as logging
-
-LOG = logging.getLogger(__name__)
-
-ENGINE = 'InnoDB'
-CHARSET = 'utf8'
-
-
-def upgrade(migrate_engine):
-    meta = MetaData()
-    meta.bind = migrate_engine
-
-    nodes = Table('nodes', meta,
-        Column('id', Integer, primary_key=True, nullable=False),
-        Column('uuid', String(length=36)),
-        Column('power_info', Text),
-        Column('cpu_arch', String(length=10)),
-        Column('cpu_num', Integer),
-        Column('memory', Integer),
-        Column('local_storage_max', Integer),
-        Column('task_state', String(length=255)),
-        Column('image_path', String(length=255), nullable=True),
-        Column('instance_uuid', String(length=36), nullable=True),
-        Column('instance_name', String(length=255), nullable=True),
-        Column('extra', Text),
-        Column('created_at', DateTime),
-        Column('updated_at', DateTime),
-        mysql_engine=ENGINE,
-        mysql_charset=CHARSET,
-    )
-
-    ifaces = Table('ifaces', meta,
-        Column('id', Integer, primary_key=True, nullable=False),
-        Column('address', String(length=18)),
-        Column('node_id', Integer, ForeignKey('nodes.id'),
-            nullable=True),
-        Column('extra', Text),
-        Column('created_at', DateTime),
-        Column('updated_at', DateTime),
-        mysql_engine=ENGINE,
-        mysql_charset=CHARSET,
-    )
-
-    tables = [nodes, ifaces]
-    for table in tables:
-        try:
-            table.create()
-        except Exception:
-            LOG.info(repr(table))
-            LOG.exception(_('Exception while creating table.'))
-            raise
-
-    indexes = [
-        Index('node_cpu_mem_disk', nodes.c.cpu_num,
-                nodes.c.memory, nodes.c.local_storage_max),
-        Index('node_instance_uuid', nodes.c.instance_uuid),
-    ]
-
-    uniques = [
-        UniqueConstraint('uuid', table=nodes,
-                            name='node_uuid_ux'),
-        UniqueConstraint('address', table=ifaces,
-                            name='iface_address_ux'),
-    ]
-
-    if migrate_engine.name == 'mysql' or migrate_engine.name == 'postgresql':
-        for index in indexes:
-            index.create(migrate_engine)
-        for index in uniques:
-            index.create(migrate_engine)
-
-
-def downgrade(migrate_engine):
-    raise NotImplementedError('Downgrade from Folsom is unsupported.')

ironic/db/sqlalchemy/migrate_repo/versions/002_nodes_use_more_json.py

@@ -1,61 +0,0 @@
-# vim: tabstop=4 shiftwidth=4 softtabstop=4
-# -*- encoding: utf-8 -*-
-#
-# Copyright 2013 Hewlett-Packard Development Company, L.P.
-#
-#    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.
-
-
-from sqlalchemy import Table, Column, MetaData
-from sqlalchemy import DateTime, Integer, String, Text
-
-from ironic.openstack.common import log as logging
-
-LOG = logging.getLogger(__name__)
-
-ENGINE = 'InnoDB'
-CHARSET = 'utf8'
-
-
-def upgrade(migrate_engine):
-    meta = MetaData()
-    meta.bind = migrate_engine
-
-    nodes = Table('nodes', meta, autoload=True)
-
-    chassis_id = Column('chassis_id', Integer, nullable=True)
-    task_start = Column('task_start', DateTime, nullable=True)
-    properties = Column('properties', Text)
-    control_driver = Column('control_driver', String(15))
-    control_info = Column('control_info', Text)
-    deploy_driver = Column('deploy_driver', String(15))
-    deploy_info = Column('deploy_info', Text)
-    reservation = Column('reservation', String(255), nullable=True)
-
-    new_cols = [chassis_id, task_start, properties, reservation,
-                control_driver, control_info, deploy_driver, deploy_info]
-    cols_to_delete = ['power_info', 'cpu_arch', 'cpu_num', 'memory',
-                      'local_storage_max', 'image_path', 'instance_name']
-
-    for col in cols_to_delete:
-        getattr(nodes.c, col).drop()
-
-    for col in new_cols:
-        nodes.create_column(col)
-
-    task_state = getattr(nodes.c, 'task_state')
-    task_state.alter(String(15))
-
-
-def downgrade(migrate_engine):
-    raise NotImplementedError('Downgrade from version 002 is unsupported.')

ironic/db/sqlalchemy/migrate_repo/versions/003_add_chassis_table.py

@@ -1,38 +0,0 @@
-# vim: tabstop=4 shiftwidth=4 softtabstop=4
-# -*- encoding: utf-8 -*-
-#
-# Copyright 2013 Hewlett-Packard Development Company, L.P.
-#
-#    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.
-
-from sqlalchemy import Table, MetaData, Column, Integer, String
-
-ENGINE = 'InnoDB'
-CHARSET = 'utf8'
-
-
-def upgrade(migrate_engine):
-    meta = MetaData()
-    meta.bind = migrate_engine
-
-    table = Table('chassis', meta,
-        Column('id', Integer, primary_key=True, nullable=False),
-        Column('uuid', String(length=36)),
-        mysql_engine=ENGINE,
-        mysql_charset=CHARSET,
-    )
-    table.create()
-
-
-def downgrade(migrate_engine):
-    raise NotImplementedError('Downgrade from version 004 is unsupported.')

ironic/db/sqlalchemy/migrate_repo/versions/004_rename_ifaces_to_ports.py

@@ -1,33 +0,0 @@
-# vim: tabstop=4 shiftwidth=4 softtabstop=4
-# -*- encoding: utf-8 -*-
-#
-# Copyright 2013 Hewlett-Packard Development Company, L.P.
-#
-#    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.
-
-from sqlalchemy import Table, MetaData
-
-ENGINE = 'InnoDB'
-CHARSET = 'utf8'
-
-
-def upgrade(migrate_engine):
-    meta = MetaData()
-    meta.bind = migrate_engine
-
-    table = Table('ifaces', meta, autoload=True)
-    table.rename('ports')
-
-
-def downgrade(migrate_engine):
-    raise NotImplementedError('Downgrade from version 003 is unsupported.')

ironic/db/sqlalchemy/migrate_repo/versions/005_drop_deploy_driver.py

@@ -1,34 +0,0 @@
-# vim: tabstop=4 shiftwidth=4 softtabstop=4
-# -*- encoding: utf-8 -*-
-#
-# Copyright 2013 Hewlett-Packard Development Company, L.P.
-#
-#    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.
-
-from sqlalchemy import Table, MetaData
-
-
-def upgrade(migrate_engine):
-    meta = MetaData()
-    meta.bind = migrate_engine
-
-    nodes = Table('nodes', meta, autoload=True)
-
-    nodes.c.deploy_driver.drop()
-    nodes.c.deploy_info.drop()
-    nodes.c.control_driver.alter(name='driver')
-    nodes.c.control_info.alter(name='driver_info')
-
-
-def downgrade(migrate_engine):
-    raise NotImplementedError('Downgrade from version 005 is unsupported.')

ironic/db/sqlalchemy/migrate_repo/versions/006_add_uuid_to_port.py

@@ -1,32 +0,0 @@
-# vim: tabstop=4 shiftwidth=4 softtabstop=4
-# -*- encoding: utf-8 -*-
-#
-# Copyright 2013 Hewlett-Packard Development Company, L.P.
-#
-#    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.
-
-from sqlalchemy import Table, Column, String, MetaData
-
-
-def upgrade(migrate_engine):
-    meta = MetaData()
-    meta.bind = migrate_engine
-
-    ports = Table('ports', meta, autoload=True)
-
-    col = Column('uuid', String(36), unique=True)
-    ports.create_column(col, unique_name="port_uuid_ux")
-
-
-def downgrade(migrate_engine):
-    raise NotImplementedError('Downgrade from version 006 is unsupported.')

ironic/db/sqlalchemy/migrate_repo/versions/007_add_extra_created_updated_to_chassis.py

@@ -1,31 +0,0 @@
-# vim: tabstop=4 shiftwidth=4 softtabstop=4
-# -*- encoding: utf-8 -*-
-#
-#    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.
-
-from sqlalchemy import Table, Column, Text, DateTime, MetaData
-
-
-def upgrade(migrate_engine):
-    meta = MetaData()
-    meta.bind = migrate_engine
-
-    chassis = Table('chassis', meta, autoload=True)
-
-    chassis.create_column(Column('extra', Text))
-    chassis.create_column(Column('created_at', DateTime))
-    chassis.create_column(Column('updated_at', DateTime))
-
-
-def downgrade(migrate_engine):
-    raise NotImplementedError('Downgrade from version 007 is unsupported.')

ironic/db/sqlalchemy/migrate_repo/versions/008_add_description_to_chassis.py

@@ -1,29 +0,0 @@
-# vim: tabstop=4 shiftwidth=4 softtabstop=4
-# -*- encoding: utf-8 -*-
-#
-#    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.
-
-from sqlalchemy import Table, Column, MetaData, String
-
-
-def upgrade(migrate_engine):
-    meta = MetaData()
-    meta.bind = migrate_engine
-
-    chassis = Table('chassis', meta, autoload=True)
-
-    chassis.create_column(Column('description', String(255), nullable=True))
-
-
-def downgrade(migrate_engine):
-    raise NotImplementedError('Downgrade from version 008 is unsupported.')

ironic/db/sqlalchemy/migrate_repo/versions/009_machine_states.py

@@ -1,39 +0,0 @@
-# vim: tabstop=4 shiftwidth=4 softtabstop=4
-# -*- encoding: utf-8 -*-
-#
-#    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.
-
-from sqlalchemy import Table, Column, MetaData, String
-
-
-def upgrade(migrate_engine):
-    meta = MetaData()
-    meta.bind = migrate_engine
-
-    nodes = Table('nodes', meta, autoload=True)
-
-    # Drop task_* columns
-    nodes.c.task_start.drop()
-    nodes.c.task_state.drop()
-
-    # Create new states columns
-    nodes.create_column(Column('power_state', String(15), nullable=True))
-    nodes.create_column(Column('target_power_state', String(15),
-                                nullable=True))
-    nodes.create_column(Column('provision_state', String(15), nullable=True))
-    nodes.create_column(Column('target_provision_state', String(15),
-                                nullable=True))
-
-
-def downgrade(migrate_engine):
-    raise NotImplementedError('Downgrade from version 009 is unsupported.')

ironic/db/sqlalchemy/migrate_repo/versions/010_add_chassis_id_fk.py

@@ -1,31 +0,0 @@
-# vim: tabstop=4 shiftwidth=4 softtabstop=4
-# -*- encoding: utf-8 -*-
-#
-#    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.
-
-from migrate.changeset import ForeignKeyConstraint
-from sqlalchemy import MetaData, Table
-
-
-def upgrade(migrate_engine):
-    meta = MetaData()
-    meta.bind = migrate_engine
-
-    nodes = Table('nodes', meta, autoload=True)
-    chassis = Table('chassis', meta, autoload=True)
-    f_key = ForeignKeyConstraint([nodes.c.chassis_id], [chassis.c.id])
-    f_key.create()
-
-
-def downgrade(migrate_engine):
-    raise NotImplementedError('Downgrade from version 010 is unsupported.')

ironic/db/sqlalchemy/migrate_repo/versions/011_add_chassis_uc.py

@@ -1,30 +0,0 @@
-# vim: tabstop=4 shiftwidth=4 softtabstop=4
-# -*- encoding: utf-8 -*-
-#
-#    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.
-
-from migrate.changeset import UniqueConstraint
-from sqlalchemy import MetaData, Table
-
-
-def upgrade(migrate_engine):
-    meta = MetaData(bind=migrate_engine)
-    t = Table('chassis', meta, autoload=True)
-
-    # NOTE: new name convention for UC
-    uc = UniqueConstraint('uuid', table=t, name='uniq_chassis0uuid')
-    uc.create()
-
-
-def downgrade(migrate_engine):
-    raise NotImplementedError('Downgrade from version 011 is unsupported.')

ironic/db/sqlalchemy/migrate_repo/versions/012_add_conductor_table.py

@@ -1,56 +0,0 @@
-# vim: tabstop=4 shiftwidth=4 softtabstop=4
-# -*- encoding: utf-8 -*-
-#
-# Copyright 2013 Hewlett-Packard Development Company, L.P.
-#
-#    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.
-
-from migrate.changeset import UniqueConstraint
-from sqlalchemy import MetaData, Table, Column, Integer, String, Text, DateTime
-
-from ironic.openstack.common import log as logging
-
-LOG = logging.getLogger(__name__)
-
-ENGINE = 'InnoDB'
-CHARSET = 'utf8'
-
-
-def upgrade(migrate_engine):
-    meta = MetaData(bind=migrate_engine)
-
-    conductor = Table('conductors', meta,
-        Column('id', Integer, primary_key=True, nullable=False),
-        Column('hostname', String(length=255), nullable=False),
-        Column('drivers', Text),
-        Column('created_at', DateTime),
-        Column('updated_at', DateTime),
-        mysql_engine=ENGINE,
-        mysql_charset=CHARSET,
-    )
-
-    try:
-        conductor.create()
-    except Exception:
-        LOG.info(repr(conductor))
-        LOG.exception(_('Exception while creating table.'))
-        raise
-
-    uc = UniqueConstraint('hostname',
-                          table=conductor,
-                          name='uniq_conductors0hostname')
-    uc.create()
-
-
-def downgrade(migrate_engine):
-    raise NotImplementedError(_('Downgrade from version 012 is unsupported.'))

ironic/db/sqlalchemy/migrate_repo/versions/013_nodes_add_last_error.py

@@ -1,30 +0,0 @@
-# vim: tabstop=4 shiftwidth=4 softtabstop=4
-# -*- encoding: utf-8 -*-
-#
-#    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.
-
-from sqlalchemy import Table, Column, MetaData, Text
-
-
-def upgrade(migrate_engine):
-    meta = MetaData()
-    meta.bind = migrate_engine
-
-    nodes = Table('nodes', meta, autoload=True)
-
-    # Create new last_error column
-    nodes.create_column(Column('last_error', Text, nullable=True))
-
-
-def downgrade(migrate_engine):
-    raise NotImplementedError('Downgrade from version 013 is unsupported.')

ironic/db/sqlalchemy/migrate_repo/versions/014_add_address_uc_sqlite.py

@@ -1,37 +0,0 @@
-# vim: tabstop=4 shiftwidth=4 softtabstop=4
-# -*- encoding: utf-8 -*-
-#
-#    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.
-
-from migrate.changeset import UniqueConstraint
-from sqlalchemy import MetaData, Table
-
-
-def upgrade(migrate_engine):
-    if migrate_engine.name == 'sqlite':
-        meta = MetaData(bind=migrate_engine)
-        ports = Table('ports', meta, autoload=True)
-
-        uniques = (
-            UniqueConstraint('address', table=ports, name='iface_address_ux'),
-            # NOTE(yuriyz): this migration can drop first UC in 'ports' table
-            # for sqlite backend (sqlalchemy-migrate bug), recreate it
-            UniqueConstraint('uuid', table=ports, name='port_uuid_ux')
-            )
-
-        for uc in uniques:
-            uc.create()
-
-
-def downgrade(migrate_engine):
-    raise NotImplementedError('Downgrade from version 014 is unsupported.')

ironic/db/sqlalchemy/migrate_repo/versions/015_nodes_add_maintenance.py

@@ -1,28 +0,0 @@
-# vim: tabstop=4 shiftwidth=4 softtabstop=4
-# -*- encoding: utf-8 -*-
-#
-#    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.
-
-from sqlalchemy import Table, Column, MetaData, Boolean
-
-
-def upgrade(migrate_engine):
-    meta = MetaData()
-    meta.bind = migrate_engine
-
-    nodes = Table('nodes', meta, autoload=True)
-    nodes.create_column(Column('maintenance', Boolean, default=False))
-
-
-def downgrade(migrate_engine):
-    raise NotImplementedError('Downgrade from version 015 is unsupported.')

ironic/db/sqlalchemy/migration.py

@@ -18,70 +18,75 @@
 
 import os
 
-import sqlalchemy
+import alembic
+from alembic import config as alembic_config
+import alembic.migration as alembic_migration
 
-from ironic.common import exception
-from ironic.db import migration
 from ironic.openstack.common.db.sqlalchemy import session as db_session
 
 
-# NOTE(jkoelker) Delay importing migrate until we are patched
-from migrate import exceptions as versioning_exceptions
-from migrate.versioning import api as versioning_api
-from migrate.versioning.repository import Repository
-
-_REPOSITORY = None
-
-get_engine = db_session.get_engine
-
-
-def db_sync(version=None):
-    if version is not None:
-        try:
-            version = int(version)
-        except ValueError:
-            raise exception.IronicException(_("version should be an integer"))
-
-    current_version = db_version()
-    repository = _find_migrate_repo()
-    if version is None or version > current_version:
-        return versioning_api.upgrade(get_engine(), repository, version)
-    else:
-        return versioning_api.downgrade(get_engine(), repository,
-                                        version)
-
-
-def db_version():
-    repository = _find_migrate_repo()
-    try:
-        return versioning_api.db_version(get_engine(), repository)
-    except versioning_exceptions.DatabaseNotControlledError:
-        meta = sqlalchemy.MetaData()
-        engine = get_engine()
-        meta.reflect(bind=engine)
-        tables = meta.tables
-        if len(tables) == 0:
-            db_version_control(migration.INIT_VERSION)
-            return versioning_api.db_version(get_engine(), repository)
-        else:
-            # Some pre-Essex DB's may not be version controlled.
-            # Require them to upgrade using Essex first.
-            raise exception.IronicException(
-                _("Upgrade DB using Essex release first."))
-
-
-def db_version_control(version=None):
-    repository = _find_migrate_repo()
-    versioning_api.version_control(get_engine(), repository, version)
-    return version
-
-
-def _find_migrate_repo():
-    """Get the path for the migrate repository."""
-    global _REPOSITORY
-    path = os.path.join(os.path.abspath(os.path.dirname(__file__)),
-                        'migrate_repo')
-    assert os.path.exists(path)
-    if _REPOSITORY is None:
-        _REPOSITORY = Repository(path)
-    return _REPOSITORY
+def _alembic_config():
+    path = os.path.join(os.path.dirname(__file__), 'alembic.ini')
+    config = alembic_config.Config(path)
+    return config
+
+
+def version(config=None):
+    """Current database version.
+
+    :returns: Database version
+    :rtype: string
+    """
+    engine = db_session.get_engine()
+    with engine.connect() as conn:
+        context = alembic_migration.MigrationContext.configure(conn)
+        return context.get_current_revision()
+
+
+def upgrade(revision, config=None):
+    """Used for upgrading database.
+
+    :param version: Desired database version
+    :type version: string
+    """
+    revision = revision or 'head'
+    config = config or _alembic_config()
+
+    alembic.command.upgrade(config, revision or 'head')
+
+
+def downgrade(revision, config=None):
+    """Used for downgrading database.
+
+    :param version: Desired database version
+    :type version: string
+    """
+    revision = revision or 'base'
+    config = config or _alembic_config()
+    return alembic.command.downgrade(config, revision)
+
+
+def stamp(revision, config=None):
+    """Stamps database with provided revision.
+    Dont run any migrations.
+
+    :param revision: Should match one from repository or head - to stamp
+                     database with most recent revision
+    :type revision: string
+    """
+    config = config or _alembic_config()
+    return alembic.command.stamp(config, revision=revision)
+
+
+def revision(message=None, autogenerate=False, config=None):
+    """Creates template for migration.
+
+    :param message: Text that will be used for migration title
+    :type message: string
+    :param autogenerate: If True - generates diff based on current database
+                         state
+    :type autogenerate: bool
+    """
+    config = config or _alembic_config()
+    return alembic.command.revision(config, message=message,
+                                    autogenerate=autogenerate)

ironic/db/sqlalchemy/models.py

@@ -110,7 +110,7 @@ class Node(Base):
 
     __tablename__ = 'nodes'
     __table_args__ = (
-        schema.UniqueConstraint('uuid', name='node_uuid_ux'),
+        schema.UniqueConstraint('uuid', name='uniq_nodes0uuid'),
         Index('node_instance_uuid', 'instance_uuid'))
     id = Column(Integer, primary_key=True)
     uuid = Column(String(36))
@@ -137,8 +137,8 @@ class Port(Base):
 
     __tablename__ = 'ports'
     __table_args__ = (
-        schema.UniqueConstraint('address', name='iface_address_ux'),
-        schema.UniqueConstraint('uuid', name='port_uuid_ux'))
+        schema.UniqueConstraint('address', name='uniq_ports0address'),
+        schema.UniqueConstraint('uuid', name='uniq_ports0uuid'))
     id = Column(Integer, primary_key=True)
     uuid = Column(String(36))
     address = Column(String(18))

ironic/tests/base.py

@@ -36,7 +36,8 @@ import testtools
 
 from oslo.config import cfg
 
-from ironic.db import migration
+from ironic.db.sqlalchemy import migration
+from ironic.db.sqlalchemy import models
 
 from ironic.common import paths
 from ironic.objects import base as objects_base
@@ -78,13 +79,14 @@ class Database(fixtures.Fixture):
         self.engine.dispose()
         conn = self.engine.connect()
         if sql_connection == "sqlite://":
-            if db_migrate.db_version() > db_migrate.INIT_VERSION:
-                return
-        else:
+            self.setup_sqlite(db_migrate)
+        elif sql_connection.startswith('sqlite:///'):
             testdb = paths.state_path_rel(sqlite_db)
             if os.path.exists(testdb):
                 return
-        db_migrate.db_sync()
+            self.setup_sqlite(db_migrate)
+        else:
+            db_migrate.upgrade('head')
         self.post_migrations()
         if sql_connection == "sqlite://":
             conn = self.engine.connect()
@@ -94,6 +96,12 @@ class Database(fixtures.Fixture):
             cleandb = paths.state_path_rel(sqlite_clean_db)
             shutil.copyfile(testdb, cleandb)
 
+    def setup_sqlite(self, db_migrate):
+        if db_migrate.version():
+            return
+        models.Base.metadata.create_all(self.engine)
+        db_migrate.stamp('head')
+
     def setUp(self):
         super(Database, self).setUp()
 
@@ -104,6 +112,7 @@ class Database(fixtures.Fixture):
         else:
             shutil.copyfile(paths.state_path_rel(self.sqlite_clean_db),
                             paths.state_path_rel(self.sqlite_db))
+            self.addCleanup(os.unlink, self.sqlite_db)
 
     def post_migrations(self):
         """Any addition steps that are needed outside of the migrations."""

ironic/tests/db/sqlalchemy/test_migrations.conf

@@ -1,7 +1,6 @@
 [DEFAULT]
 # Set up any number of migration data stores you want, one
 # The "name" used in the test is the config variable key.
-#sqlite=sqlite:///test_migrations.db
-sqlite=sqlite://
+# sqlite migrations not supported by alembic
 #mysql=mysql://root:@localhost/test_migrations
 #postgresql=postgresql://user:pass@localhost/test_migrations

ironic/tests/db/sqlalchemy/test_migrations.py

@@ -41,21 +41,21 @@ postgres=# create database openstack_citest with owner openstack_citest;
 """
 
 import ConfigParser
+import contextlib
 import fixtures
 import os
 import subprocess
 import urlparse
 
-from migrate.versioning import repository
+from alembic import script
 import mock
 import sqlalchemy
 import sqlalchemy.exc
 
-from ironic.openstack.common.db.sqlalchemy import utils as db_utils
+from ironic.db.sqlalchemy import migration
+from ironic.openstack.common.db.sqlalchemy import session
 from ironic.openstack.common import lockutils
 from ironic.openstack.common import log as logging
-
-import ironic.db.sqlalchemy.migrate_repo
 from ironic.tests import base
 
 LOG = logging.getLogger(__name__)
@@ -76,7 +76,7 @@ def _get_connect_string(backend, user, passwd, database):
 
     return ("%(backend)s://%(user)s:%(passwd)s@localhost/%(database)s"
             % {'backend': backend, 'user': user, 'passwd': passwd,
-            'database': database})
+               'database': database})
 
 
 def _is_backend_avail(backend, user, passwd, database):
@@ -122,6 +122,18 @@ def get_db_connection_info(conn_pieces):
     return (user, password, database, host)
 
 
+@contextlib.contextmanager
+def patch_with_engine(engine):
+    with mock.patch(('ironic.openstack.common.db'
+                     '.sqlalchemy.session.get_engine')) as patch_migration:
+        with mock.patch(('ironic.db.sqlalchemy.migration'
+                         '.db_session.get_engine')) as patch_env:
+            patch_migration.return_value = engine
+            patch_env.return_value = engine
+
+            yield
+
+
 class BaseMigrationTestCase(base.TestCase):
     """Base class fort testing of migration utils."""
 
@@ -142,7 +154,6 @@ class BaseMigrationTestCase(base.TestCase):
 
         # Load test databases from the config file. Only do this
         # once. No need to re-run this on each test...
-        LOG.debug(_('config_path is %s') % self.CONFIG_FILE_PATH)
         if os.path.exists(self.CONFIG_FILE_PATH):
             cp = ConfigParser.RawConfigParser()
             try:
@@ -159,7 +170,7 @@ class BaseMigrationTestCase(base.TestCase):
 
         self.engines = {}
         for key, value in self.test_databases.items():
-            self.engines[key] = sqlalchemy.create_engine(value)
+            self.engines[key] = session.create_engine(value)
 
         # We start each test case with a completely blank slate.
         self.temp_dir = self.useFixture(fixtures.TempDir())
@@ -235,65 +246,49 @@ class BaseMigrationTestCase(base.TestCase):
 
 
 class WalkVersionsMixin(object):
-    def _walk_versions(self, engine=None, snake_walk=False, downgrade=True):
+    def _walk_versions(self, engine=None, alembic_cfg=None, downgrade=True):
         # Determine latest version script from the repo, then
         # upgrade from 1 through to the latest, with no data
         # in the databases. This just checks that the schema itself
         # upgrades successfully.
 
         # Place the database under version control
-        self.migration_api.version_control(engine, self.REPOSITORY,
-                                           self.INIT_VERSION)
-        self.assertEqual(self.INIT_VERSION,
-                         self.migration_api.db_version(engine,
-                                                       self.REPOSITORY))
-
-        LOG.debug(_('latest version is %s') % self.REPOSITORY.latest)
-        versions = range(self.INIT_VERSION + 1, self.REPOSITORY.latest + 1)
-
-        for version in versions:
-            # upgrade -> downgrade -> upgrade
-            self._migrate_up(engine, version, with_data=True)
-            if snake_walk:
-                downgraded = self._migrate_down(
-                    engine, version - 1, with_data=True)
-                if downgraded:
-                    self._migrate_up(engine, version)
-
-        if downgrade:
-            # Now walk it back down to 0 from the latest, testing
-            # the downgrade paths.
-            for version in reversed(versions):
-                # downgrade -> upgrade -> downgrade
-                downgraded = self._migrate_down(engine, version - 1)
-
-                if snake_walk and downgraded:
-                    self._migrate_up(engine, version)
-                    self._migrate_down(engine, version - 1)
-
-    def _migrate_down(self, engine, version, with_data=False):
+        with patch_with_engine(engine):
+
+            script_directory = script.ScriptDirectory.from_config(alembic_cfg)
+
+            self.assertIsNone(self.migration_api.version(alembic_cfg))
+
+            for version in script_directory.walk_revisions():
+                self._migrate_up(engine, alembic_cfg,
+                                 version.revision, with_data=True)
+
+            if downgrade:
+                for version in reversed(script_directory.walk_revisions()):
+                    self._migrate_down(engine, alembic_cfg, version.revision)
+
+    def _migrate_down(self, engine, config, version, with_data=False):
         try:
-            self.migration_api.downgrade(engine, self.REPOSITORY, version)
+            self.migration_api.downgrade(version, config=config)
         except NotImplementedError:
             # NOTE(sirp): some migrations, namely release-level
             # migrations, don't support a downgrade.
             return False
 
-        self.assertEqual(
-            version, self.migration_api.db_version(engine, self.REPOSITORY))
+        self.assertEqual(version, self.migration_api.version(config))
 
         # NOTE(sirp): `version` is what we're downgrading to (i.e. the 'target'
         # version). So if we have any downgrade checks, they need to be run for
         # the previous (higher numbered) migration.
         if with_data:
             post_downgrade = getattr(
-                self, "_post_downgrade_%03d" % (version + 1), None)
+                self, "