Removes downgrade from db migration scripts

downgrade is not to be supported from kilo release
onwards and is good to clean up the code.

Closes-bug: #1668887

Change-Id: I4b3f264d8691b74d602df466752eccbea533c209

tacker/db/migration/README

@@ -16,7 +16,7 @@
 
 The migrations in the alembic/versions contain the changes needed to migrate
 from older Tacker releases to newer versions. A migration occurs by executing
-a script that details the changes needed to upgrade/downgrade the database. The
+a script that details the changes needed to upgrade the database. The
 migration scripts are ordered so that multiple scripts can run sequentially to
 update the database. The scripts are executed by Tacker's migration wrapper
 which uses the Alembic library to manage the migration.  Tacker supports
@@ -50,15 +50,11 @@ Upgrade the database incrementally:
 $ tacker-db-manage --config-file /path/to/tacker.conf \
 --config-file /path/to/plugin/config.ini upgrade --delta <# of revs>
 
-Downgrade the database by a certain number of revisions:
-$ tacker-db-manage --config-file /path/to/tacker.conf \
---config-file /path/to/plugin/config.ini downgrade --delta <# of revs>
-
 
 DEVELOPERS:
 A database migration script is required when you submit a change to Tacker
 that alters the database model definition.  The migration script is a special
-python file that includes code to update/downgrade the database to match the
+python file that includes code to upgrade the database to match the
 changes in the model definition. Alembic will execute these scripts in order to
 provide a linear migration path between revision. The tacker-db-manage command
 can be used to generate migration template for you to complete.  The operations
@@ -74,7 +70,7 @@ database state with the models.  You should inspect the autogenerated template
 to ensure that the proper models have been altered.
 
 In rare circumstances, you may want to start with an empty migration template
-and manually author the changes necessary for an upgrade/downgrade.  You can
+and manually author the changes necessary for an upgrade.  You can
 create a blank file via:
 
 $ tacker-db-manage --config-file /path/to/tacker.conf \
@@ -82,8 +78,7 @@ $ tacker-db-manage --config-file /path/to/tacker.conf \
 -m "description of revision"
 
 The migration timeline should remain linear so that there is a clear path when
-upgrading/downgrading.  To verify that the timeline does branch, you can run
+upgrading.  To verify that the timeline does branch, you can run this command:
-this command:
 $ tacker-db-manage --config-file /path/to/tacker.conf \
 --config-file /path/to/plugin/config.ini check_migration
 

tacker/db/migration/alembic_migrations/script.py.mako

@@ -34,7 +34,3 @@ from tacker.db import migration
 
 def upgrade(active_plugins=None, options=None):
     ${upgrades if upgrades else "pass"}
-
-
-def downgrade(active_plugins=None, options=None):
-    ${downgrades if downgrades else "pass"}

tacker/db/migration/alembic_migrations/versions/12a57080b277_add_service_db.py

@@ -96,13 +96,3 @@ def upgrade(active_plugins=None, options=None):
         mysql_engine='InnoDB'
     )
     # end Alembic commands #
-
-
-def downgrade(active_plugins=None, options=None):
-    # commands auto generated by Alembic - please adjust! #
-    op.drop_table('servicedevicebindings')
-    op.drop_table('servicecontexts')
-    op.drop_table('serviceinstances')
-    op.drop_table('deviceservicecontexts')
-    op.drop_table('servicetypes')
-    # end Alembic commands #

tacker/db/migration/alembic_migrations/versions/12a57080b278_alter_devices.py

@@ -40,14 +40,3 @@ def upgrade(active_plugins=None, options=None):
     op.alter_column(u'devices', 'status', existing_type=mysql.VARCHAR(
         length=255), nullable=False)
     # end Alembic commands #s
-
-
-def downgrade(active_plugins=None, options=None):
-    # commands auto generated by Alembic - please adjust! #
-    op.alter_column(u'devices', 'status',
-                    existing_type=mysql.VARCHAR(length=255),
-                    nullable=True)
-    op.alter_column(u'deviceattributes', 'device_id',
-                    existing_type=mysql.VARCHAR(length=255),
-                    nullable=True)
-    # end Alembic commands #

tacker/db/migration/alembic_migrations/versions/22f5385a3d4f_remove_proxydb.py

@@ -33,7 +33,3 @@ def upgrade(active_plugins=None, options=None):
     op.drop_table('proxymgmtports')
     op.drop_table('proxyserviceports')
     # end Alembic commands #
-
-
-def downgrade(active_plugins=None, options=None):
-    pass

tacker/db/migration/alembic_migrations/versions/2774a42c7163_remove_service_related.py

@@ -26,8 +26,6 @@ revision = '2774a42c7163'
 down_revision = '12a57080b278'
 
 from alembic import op
-import sqlalchemy as sa
-from sqlalchemy.dialects import mysql
 
 
 def upgrade(active_plugins=None, options=None):
@@ -37,79 +35,3 @@ def upgrade(active_plugins=None, options=None):
     op.drop_table('servicedevicebindings')
     op.drop_table('serviceinstances')
     # end Alembic commands #
-
-
-def downgrade(active_plugins=None, options=None):
-    # commands auto generated by Alembic - please adjust! #
-    op.create_table(
-        'deviceservicecontexts',
-        sa.Column('id', mysql.VARCHAR(length=36), nullable=False),
-        sa.Column('device_id', mysql.VARCHAR(length=36), nullable=True),
-        sa.Column('network_id', mysql.VARCHAR(length=36), nullable=True),
-        sa.Column('subnet_id', mysql.VARCHAR(length=36), nullable=True),
-        sa.Column('port_id', mysql.VARCHAR(length=36), nullable=True),
-        sa.Column('router_id', mysql.VARCHAR(length=36), nullable=True),
-        sa.Column('role', mysql.VARCHAR(length=255), nullable=True),
-        sa.Column('index', mysql.INTEGER(display_width=11),
-                  autoincrement=False, nullable=True),
-        sa.ForeignKeyConstraint(['device_id'], [u'devices.id'],
-                                name=u'deviceservicecontexts_ibfk_1'),
-        sa.PrimaryKeyConstraint('id'),
-        mysql_default_charset=u'utf8',
-        mysql_engine=u'InnoDB'
-    )
-
-    op.create_table(
-        'serviceinstances',
-        sa.Column('tenant_id', mysql.VARCHAR(length=255), nullable=True),
-        sa.Column('id', mysql.VARCHAR(length=36), nullable=False),
-        sa.Column('name', mysql.VARCHAR(length=255), nullable=True),
-        sa.Column('service_type_id', mysql.VARCHAR(length=36), nullable=True),
-        sa.Column('service_table_id', mysql.VARCHAR(length=36), nullable=True),
-        sa.Column('managed_by_user', mysql.TINYINT(display_width=1),
-                  autoincrement=False, nullable=True),
-        sa.Column('mgmt_driver', mysql.VARCHAR(length=255), nullable=True),
-        sa.Column('mgmt_url', mysql.VARCHAR(length=255), nullable=True),
-        sa.Column('status', mysql.VARCHAR(length=255), nullable=False),
-        sa.ForeignKeyConstraint(['service_type_id'], [u'servicetypes.id'],
-                                name=u'serviceinstances_ibfk_1'),
-        sa.PrimaryKeyConstraint('id'),
-        mysql_default_charset=u'utf8',
-        mysql_engine=u'InnoDB'
-    )
-
-    op.create_table(
-        'servicedevicebindings',
-        sa.Column('service_instance_id', mysql.VARCHAR(length=36),
-                  nullable=False),
-        sa.Column('device_id', mysql.VARCHAR(length=36), nullable=False),
-        sa.ForeignKeyConstraint(['device_id'], [u'devices.id'],
-                                name=u'servicedevicebindings_ibfk_1'),
-        sa.ForeignKeyConstraint(['service_instance_id'],
-                                [u'serviceinstances.id'],
-                                name=u'servicedevicebindings_ibfk_2'),
-        sa.PrimaryKeyConstraint('service_instance_id', 'device_id'),
-        mysql_default_charset=u'utf8',
-        mysql_engine=u'InnoDB'
-    )
-
-    op.create_table(
-        'servicecontexts',
-        sa.Column('id', mysql.VARCHAR(length=36), nullable=False),
-        sa.Column('service_instance_id', mysql.VARCHAR(length=36),
-                  nullable=True),
-        sa.Column('network_id', mysql.VARCHAR(length=36), nullable=True),
-        sa.Column('subnet_id', mysql.VARCHAR(length=36), nullable=True),
-        sa.Column('port_id', mysql.VARCHAR(length=36), nullable=True),
-        sa.Column('router_id', mysql.VARCHAR(length=36), nullable=True),
-        sa.Column('role', mysql.VARCHAR(length=255), nullable=True),
-        sa.Column('index', mysql.INTEGER(display_width=11),
-                  autoincrement=False, nullable=True),
-        sa.ForeignKeyConstraint(['service_instance_id'],
-                                [u'serviceinstances.id'],
-                                name=u'servicecontexts_ibfk_1'),
-        sa.PrimaryKeyConstraint('id'),
-        mysql_default_charset=u'utf8',
-        mysql_engine=u'InnoDB'
-    )
-    # end Alembic commands #

tacker/db/migration/alembic_migrations/versions/5246a6bd410f_multisite_vim.py

@@ -58,11 +58,3 @@ def upgrade(active_plugins=None, options=None):
     op.add_column(u'devices', sa.Column('vim_id', sa.String(length=36),
                                         nullable=False))
     op.create_foreign_key(None, 'devices', 'vims', ['vim_id'], ['id'])
-
-
-def downgrade(active_plugins=None, options=None):
-    op.drop_constraint(None, 'devices', type_='foreignkey')
-    op.drop_column(u'devices', 'vim_id')
-    op.drop_column(u'devices', 'placement_attr')
-    op.drop_table('vimauths')
-    op.drop_table('vims')

tacker/db/migration/alembic_migrations/versions/8f7145914cb0_remove_infra_driver_column.py

@@ -26,14 +26,7 @@ revision = '8f7145914cb0'
 down_revision = '0ae5b1ce3024'
 
 from alembic import op
-import sqlalchemy as sa
-from sqlalchemy.dialects import mysql
 
 
 def upgrade(active_plugins=None, options=None):
     op.drop_column('vnfd', 'infra_driver')
-
-
-def downgrade(active_plugins=None, options=None):
-    op.add_column('vnfd', sa.Column('infra_driver', mysql.VARCHAR(length=255),
-                                    nullable=True))

tacker/db/migration/alembic_migrations/versions/acf941e54075_add_error_reason_to_device.py

@@ -32,7 +32,3 @@ import sqlalchemy as sa
 def upgrade(active_plugins=None, options=None):
     op.add_column('devices', sa.Column('error_reason',
         sa.Text(), nullable=True))
-
-
-def downgrade(active_plugins=None, options=None):
-    op.drop_column('devices', 'error_reason')

tacker/db/migration/alembic_migrations/versions/e8918cda6433_add_attributes_to_vnffg.py

@@ -32,7 +32,3 @@ from tacker.db.types import Json
 
 def upgrade(active_plugins=None, options=None):
     op.add_column('vnffgs', sa.Column('attributes', Json))
-
-
-def downgrade(active_plugins=None, options=None):
-    op.drop_column('vnffgs', 'attributes')

tacker/db/migration/cli.py

@@ -53,15 +53,14 @@ def do_check_migration(config, cmd):
     validate_head_file(config)
 
 
-def do_upgrade_downgrade(config, cmd):
+def do_upgrade(config, cmd):
     if not CONF.command.revision and not CONF.command.delta:
         raise SystemExit(_('You must provide a revision or relative delta'))
 
     revision = CONF.command.revision
 
     if CONF.command.delta:
-        sign = '+' if CONF.command.name == 'upgrade' else '-'
+        revision = '+%s' % str(CONF.command.delta)
-        revision = sign + str(CONF.command.delta)
     else:
         revision = CONF.command.revision
 
@@ -121,12 +120,11 @@ def add_command_parsers(subparsers):
     parser = subparsers.add_parser('check_migration')
     parser.set_defaults(func=do_check_migration)
 
-    for name in ['upgrade', 'downgrade']:
+    parser = subparsers.add_parser('upgrade')
-        parser = subparsers.add_parser(name)
     parser.add_argument('--delta', type=int)
     parser.add_argument('--sql', action='store_true')
     parser.add_argument('revision', nargs='?')
-        parser.set_defaults(func=do_upgrade_downgrade)
+    parser.set_defaults(func=do_upgrade)
 
     parser = subparsers.add_parser('stamp')
     parser.add_argument('--sql', action='store_true')

tacker/tests/unit/test_db_migration.py

@@ -108,21 +108,6 @@ class TestCli(base.BaseTestCase):
             {'sql': False}
         )
 
-    def test_downgrade(self):
-        self._main_test_helper(
-            ['prog', 'downgrade', '--sql', 'folsom'],
-            'downgrade',
-            ('folsom',),
-            {'sql': True}
-        )
-
-        self._main_test_helper(
-            ['prog', 'downgrade', '--delta', '2'],
-            'downgrade',
-            ('-2',),
-            {'sql': False}
-        )
-
     def _test_validate_head_file_helper(self, heads, file_content=None):
         with mock.patch('alembic.script.ScriptDirectory.from_config') as fc:
             fc.return_value.get_heads.return_value = heads