Remove DB downgrade

As downgrade are not supported after Kilo, we should remove them now.
Roll backs can be performed as mentioned in the below link:
http://docs.openstack.org/ops-guide/ops-upgrades.html#rolling-back-a-failed-upgrade

The DB downgrades were deprecated in Glance Mitaka release by commit
e3366af.

Change-Id: I937d15d93f16a3e44a50e6ff1a469098eab67c79
Implements: blueprint remove-db-downgrade

doc/source/db.rst

@@ -53,8 +53,9 @@ This will take an existing database and upgrade it to the specified VERSION.
 Downgrading an Existing Database
 --------------------------------
 
-    glance-manage db downgrade <VERSION>
-
-This will downgrade an existing database from the current version to the
-specified VERSION.
+Upgrades involve complex operations and can fail. Before attempting any
+upgrade, you should make a full database backup of your production data. As of
+Kilo, database downgrades are not supported, and the only method available to
+get back to a prior database version is to restore from backup[1].
 
+[1]: http://docs.openstack.org/ops-guide/ops-upgrades.html#perform-a-backup

doc/source/man/glancemanage.rst

@@ -50,10 +50,6 @@ COMMANDS
         This will take an existing database and upgrade it to the
         specified VERSION.
 
-  **db_downgrade <VERSION>**
-        This will take an existing database and downgrade it to the
-        specified VERSION.
-
   **db_version_control**
         Place the database under migration control.
 

glance/cmd/manage.py

@@ -84,17 +84,6 @@ def upgrade(self, version=None):
                           db_migration.MIGRATE_REPO_PATH,
                           version)
 
-    @args('--version', metavar='<version>', help='Database version')
-    def downgrade(self, version=None):
-        """Downgrade the database's migration level"""
-        print("Warning: DB downgrade is deprecated and will be removed in N "
-              "release. Users should make a full database backup of the "
-              "production data before attempting any upgrade.",
-              file=sys.stderr)
-        migration.db_sync(db_api.get_engine(),
-                          db_migration.MIGRATE_REPO_PATH,
-                          version)
-
     @args('--version', metavar='<version>', help='Database version')
     def version_control(self, version=None):
         """Place a database under migration control"""
@@ -107,7 +96,7 @@ def version_control(self, version=None):
           help='Current Database version')
     def sync(self, version=None, current_version=None):
         """
-        Place a database under migration control and upgrade/downgrade it,
+        Place a database under migration control and upgrade it,
         creating first if necessary.
         """
         if current_version not in (None, 'None'):
@@ -193,13 +182,6 @@ def version(self):
     def upgrade(self, version=None):
         self.command_object.upgrade(CONF.command.version)
 
-    def downgrade(self, version=None):
-        print("Warning: DB downgrade is deprecated and will be removed in N "
-              "release. Users should make a full database backup of the "
-              "production data before attempting any upgrade.",
-              file=sys.stderr)
-        self.command_object.downgrade(CONF.command.version)
-
     def version_control(self, version=None):
         self.command_object.version_control(CONF.command.version)
 
@@ -234,11 +216,6 @@ def add_legacy_command_parsers(command_object, subparsers):
     parser.add_argument('version', nargs='?')
     parser.set_defaults(action='db_upgrade')
 
-    parser = subparsers.add_parser('db_downgrade')
-    parser.set_defaults(action_fn=legacy_command_object.downgrade)
-    parser.add_argument('version')
-    parser.set_defaults(action='db_downgrade')
-
     parser = subparsers.add_parser('db_version_control')
     parser.set_defaults(action_fn=legacy_command_object.version_control)
     parser.add_argument('version', nargs='?')

glance/db/sqlalchemy/migrate_repo/versions/001_add_images_table.py

@@ -16,7 +16,7 @@
 from sqlalchemy.schema import (Column, MetaData, Table)
 
 from glance.db.sqlalchemy.migrate_repo.schema import (
-    Boolean, DateTime, Integer, String, Text, create_tables, drop_tables)  # noqa
+    Boolean, DateTime, Integer, String, Text, create_tables)  # noqa
 
 
 def define_images_table(meta):
@@ -53,10 +53,3 @@ def upgrade(migrate_engine):
     meta.bind = migrate_engine
     tables = [define_images_table(meta)]
     create_tables(tables)
-
-
-def downgrade(migrate_engine):
-    meta = MetaData()
-    meta.bind = migrate_engine
-    tables = [define_images_table(meta)]
-    drop_tables(tables)

glance/db/sqlalchemy/migrate_repo/versions/002_add_image_properties_table.py

@@ -17,7 +17,7 @@
     Column, ForeignKey, Index, MetaData, Table, UniqueConstraint)
 
 from glance.db.sqlalchemy.migrate_repo.schema import (
-    Boolean, DateTime, Integer, String, Text, create_tables, drop_tables,
+    Boolean, DateTime, Integer, String, Text, create_tables,
     from_migration_import)  # noqa
 
 
@@ -76,10 +76,3 @@ def upgrade(migrate_engine):
     meta.bind = migrate_engine
     tables = [define_image_properties_table(meta)]
     create_tables(tables)
-
-
-def downgrade(migrate_engine):
-    meta = MetaData()
-    meta.bind = migrate_engine
-    tables = [define_image_properties_table(meta)]
-    drop_tables(tables)

glance/db/sqlalchemy/migrate_repo/versions/003_add_disk_format.py

@@ -13,7 +13,6 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from migrate.changeset import *  # noqa
 from sqlalchemy import *  # noqa
 
 from glance.db.sqlalchemy.migrate_repo.schema import (
@@ -53,17 +52,6 @@ def get_images_table(meta):
     return images
 
 
-def get_image_properties_table(meta):
-    """
-    No changes to the image properties table from 002...
-    """
-    (define_image_properties_table,) = from_migration_import(
-        '002_add_image_properties_table', ['define_image_properties_table'])
-
-    image_properties = define_image_properties_table(meta)
-    return image_properties
-
-
 def upgrade(migrate_engine):
     meta = MetaData()
     meta.bind = migrate_engine
@@ -119,35 +107,3 @@ def upgrade(migrate_engine):
     container_format.create(images)
 
     images.columns['type'].drop()
-
-
-def downgrade(migrate_engine):
-    meta = MetaData()
-    meta.bind = migrate_engine
-
-    # Steps to take, in this order:
-    # 1) Add type column back to Image
-    # 2) Move the existing type properties from ImageProperty into
-    #    Image.type
-    # 3) Drop the disk_format and container_format columns in Image
-
-    conn = migrate_engine.connect()
-    images = get_images_table(meta)
-    image_properties = get_image_properties_table(meta)
-
-    type_col = Column('type', String(30))
-    type_col.create(images)
-
-    sel = select([image_properties]).where(image_properties.c.key == 'type')
-    type_property_records = conn.execute(sel).fetchall()
-    for record in type_property_records:
-        upd = images.update().where(
-            images.c.id == record.image_id).values(type=record.value)
-        conn.execute(upd)
-        dlt = image_properties.delete().where(
-            image_properties.c.image_id == record.image_id)
-        conn.execute(dlt)
-    conn.close()
-
-    images.columns['disk_format'].drop()
-    images.columns['container_format'].drop()

glance/db/sqlalchemy/migrate_repo/versions/004_add_checksum.py

@@ -13,7 +13,6 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from migrate.changeset import *  # noqa
 from sqlalchemy import *  # noqa
 
 from glance.db.sqlalchemy.migrate_repo.schema import (
@@ -73,12 +72,3 @@ def upgrade(migrate_engine):
 
     checksum = Column('checksum', String(32))
     checksum.create(images)
-
-
-def downgrade(migrate_engine):
-    meta = MetaData()
-    meta.bind = migrate_engine
-
-    images = get_images_table(meta)
-
-    images.columns['checksum'].drop()

glance/db/sqlalchemy/migrate_repo/versions/005_size_big_integer.py

@@ -13,7 +13,6 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from migrate.changeset import *  # noqa
 from sqlalchemy import *  # noqa
 
 from glance.db.sqlalchemy.migrate_repo.schema import (
@@ -54,17 +53,6 @@ def get_images_table(meta):
     return images
 
 
-def get_image_properties_table(meta):
-    """
-    No changes to the image properties table from 002...
-    """
-    (define_image_properties_table,) = from_migration_import(
-        '002_add_image_properties_table', ['define_image_properties_table'])
-
-    image_properties = define_image_properties_table(meta)
-    return image_properties
-
-
 def upgrade(migrate_engine):
     meta = MetaData()
     meta.bind = migrate_engine
@@ -84,21 +72,3 @@ def upgrade(migrate_engine):
 
         images = get_images_table(meta)
         images.columns['size'].alter(type=BigInteger())
-
-
-def downgrade(migrate_engine):
-    meta = MetaData()
-    meta.bind = migrate_engine
-
-    # No changes to SQLite stores are necessary, since
-    # there is no BIG INTEGER type in SQLite. Unfortunately,
-    # running the Python 005_size_big_integer.py migration script
-    # on a SQLite datastore results in an error in the sa-migrate
-    # code that does the workarounds for SQLite not having
-    # ALTER TABLE MODIFY COLUMN ability
-
-    dialect = migrate_engine.url.get_dialect().name
-
-    if not dialect.startswith('sqlite'):
-        images = get_images_table(meta)
-        images.columns['size'].alter(type=Integer())

glance/db/sqlalchemy/migrate_repo/versions/006_key_to_name.py

@@ -13,11 +13,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from migrate.changeset import *  # noqa
 from sqlalchemy import *  # noqa
 
-from glance.db.sqlalchemy.migrate_repo.schema import (
-    Boolean, DateTime, Integer, String, Text, from_migration_import)  # noqa
+from glance.db.sqlalchemy.migrate_repo.schema import from_migration_import
 
 
 def get_images_table(meta):
@@ -31,44 +29,6 @@ def get_images_table(meta):
     return images
 
 
-def get_image_properties_table(meta):
-    """
-    Returns the Table object for the image_properties table that
-    corresponds to the image_properties table definition of this version.
-    """
-    (get_images_table,) = from_migration_import(
-        '004_add_checksum', ['get_images_table'])
-
-    images = get_images_table(meta)  # noqa
-
-    image_properties = Table('image_properties',
-                             meta,
-                             Column('id',
-                                    Integer(),
-                                    primary_key=True,
-                                    nullable=False),
-                             Column('image_id',
-                                    Integer(),
-                                    ForeignKey('images.id'),
-                                    nullable=False,
-                                    index=True),
-                             Column('name', String(255), nullable=False),
-                             Column('value', Text()),
-                             Column('created_at', DateTime(), nullable=False),
-                             Column('updated_at', DateTime()),
-                             Column('deleted_at', DateTime()),
-                             Column('deleted',
-                                    Boolean(),
-                                    nullable=False,
-                                    default=False,
-                                    index=True),
-                             UniqueConstraint('image_id', 'name'),
-                             mysql_engine='InnoDB',
-                             extend_existing=True)
-
-    return image_properties
-
-
 def upgrade(migrate_engine):
     meta = MetaData()
     meta.bind = migrate_engine
@@ -97,30 +57,3 @@ def upgrade(migrate_engine):
 
         image_properties = get_image_properties_table(meta)
         image_properties.columns['key'].alter(name="name")
-
-
-def downgrade(migrate_engine):
-    meta = MetaData()
-    meta.bind = migrate_engine
-
-    image_properties = get_image_properties_table(meta)
-
-    if migrate_engine.name == "ibm_db_sa":
-        # NOTE(dperaza) ibm db2 does not allow ALTER INDEX so we will drop
-        # the index, rename the column, then re-create the index
-        sql_commands = [
-            """ALTER TABLE image_properties DROP UNIQUE
-                ix_image_properties_image_id_name;""",
-            """ALTER TABLE image_properties RENAME COLUMN name to \"key\";""",
-            """ALTER TABLE image_properties ADD CONSTRAINT
-                ix_image_properties_image_id_key UNIQUE(image_id, \"key\");""",
-        ]
-        for command in sql_commands:
-            meta.bind.execute(command)
-    else:
-        index = Index('ix_image_properties_image_id_name',
-                      image_properties.c.image_id,
-                      image_properties.c.name)
-        index.rename('ix_image_properties_image_id_key')
-
-        image_properties.columns['name'].alter(name="key")