Change to use alembic to create db table schema

neutron removed the capability to auto generating the table schema and
use the alembic as the only way to create the db tables. powervc neutron
agent needs to follow the same way to create the tables schema and it
also added the db schema migration capability for powervc neutron agent.

As db2 alembic has problem at this time, I still retain the auto create
the table schema during startup, once db2 alembic is enabled, then we
can totally switch to use alembic to create the db schema

Change-Id: I4b5982b2f67b33aae3b8acc65b91fc6247b9b8a4

neutron-powervc/bin/neutron-powervc-db-manage

@@ -0,0 +1,9 @@
+#!/usr/bin/env python
+
+import sys
+
+from powervc.neutron.db.migration.cli import main
+
+
+if __name__ == "__main__":
+    sys.exit(main())

neutron-powervc/powervc/neutron/db/migration/__init__.py

@@ -0,0 +1 @@
+# Copyright 2014 IBM Corp.

neutron-powervc/powervc/neutron/db/migration/alembic.ini

@@ -0,0 +1,59 @@
+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts
+script_location = alembic_migration
+
+# 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
+
+# set to 'true' to allow .pyc and .pyo files without
+# a source .py file to be detected as revisions in the
+# versions/ directory
+# sourceless = false
+
+sqlalchemy.url =
+
+
+# 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

neutron-powervc/powervc/neutron/db/migration/alembic_migration/README

@@ -0,0 +1 @@
+Generic single-database configuration.

neutron-powervc/powervc/neutron/db/migration/alembic_migration/env.py

@@ -0,0 +1,67 @@
+# Copyright 2014 IBM Corp.
+
+from __future__ import with_statement
+from alembic import context
+from sqlalchemy import engine_from_config, pool
+from logging.config import fileConfig
+from oslo.db.sqlalchemy import session
+from powervc.neutron.db.powervc_models_v2 import PowerVCMapping
+
+# 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.
+fileConfig(config.config_file_name)
+
+# set the target for 'autogenerate' support
+target_metadata = PowerVCMapping.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_offline():
+    """Run migrations in 'offline' mode.
+
+    This configures the context with just a URL
+    and not an Engine, though an Engine is acceptable
+    here as well.  By skipping the Engine creation
+    we don't even need a DBAPI to be available.
+
+    Calls to context.execute() here emit the given string to the
+    script output.
+
+    """
+    url = config.powervc_config.DATABASE.connection
+    context.configure(url=url, target_metadata=target_metadata)
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+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 = session.create_engine(config.powervc_config.DATABASE.connection)
+    connection = engine.connect()
+    context.configure(connection=connection,
+                      target_metadata=target_metadata)
+
+    try:
+        with context.begin_transaction():
+            context.run_migrations()
+    finally:
+        connection.close()
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()

neutron-powervc/powervc/neutron/db/migration/alembic_migration/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"}

neutron-powervc/powervc/neutron/db/migration/alembic_migration/versions/1ba55441bcc2_powervcmappings.py

@@ -0,0 +1,56 @@
+"""create powervcmappings tables
+
+Revision ID: 1ba55441bcc2
+Revises: None
+Create Date: 2014-08-27 16:24:01.765923
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '1ba55441bcc2'
+down_revision = None
+
+from alembic import op
+import sqlalchemy as sa
+from oslo.db.sqlalchemy import session
+from alembic import util as alembic_util
+from alembic import context
+from neutron.openstack.common import uuidutils
+from powervc.neutron.common import constants
+
+tablename = 'powervcmappings'
+
+
+def upgrade():
+    url = context.config.powervc_config.DATABASE.connection
+    engine = session.create_engine(url)
+    # In previous release, we do not use alembic or any other migration,
+    # as we need to support migration case, we need to check if the table
+    # exists or not
+    if engine.dialect.has_table(engine.connect(), tablename):
+        alembic_util.msg("table has been already exists!")
+        return
+    op.create_table(
+        tablename,
+        sa.Column('id', sa.String(36),
+                  primary_key=True,
+                  default=uuidutils.generate_uuid),
+        sa.Column('obj_type', sa.Enum(constants.OBJ_TYPE_NETWORK,
+                                      constants.OBJ_TYPE_SUBNET,
+                                      constants.OBJ_TYPE_PORT,
+                                      name='mapping_object_type'),
+                  nullable=False),
+        sa.Column('status', sa.Enum(constants.STATUS_CREATING,
+                                    constants.STATUS_ACTIVE,
+                                    constants.STATUS_DELETING,
+                                    name='mapping_state'),
+                  nullable=False),
+        sa.Column('sync_key', sa.String(255), nullable=False),
+        sa.Column('local_id', sa.String(36)),
+        sa.Column('pvc_id', sa.String(36)),
+        sa.Column('update_data', sa.String(512))
+    )
+
+
+def downgrade():
+    op.drop_table(tablename)

neutron-powervc/powervc/neutron/db/migration/cli.py

@@ -0,0 +1,147 @@
+# Copyright 2014 IBM Corp.
+
+import os
+
+import neutron
+
+from alembic import command as alembic_command
+from alembic import config as alembic_config
+from alembic import script as alembic_script
+from alembic import util as alembic_util
+from oslo.config import cfg
+
+
+HEAD_FILENAME = 'HEAD'
+
+_db_opts = [
+    cfg.StrOpt('connection',
+               deprecated_name='sql_connection',
+               default='',
+               secret=True,
+               help=_('URL to database')),
+    cfg.StrOpt('engine',
+               default='',
+               help=_('Database engine')),
+]
+
+CONF = cfg.ConfigOpts()
+CONF.register_cli_opts(_db_opts, 'DATABASE')
+
+
+def do_alembic_command(config, cmd, *args, **kwargs):
+    try:
+        getattr(alembic_command, cmd)(config, *args, **kwargs)
+    except alembic_util.CommandError as e:
+        alembic_util.err(str(e))
+
+
+def do_check_migration(config, cmd):
+    do_alembic_command(config, 'branches')
+    validate_head_file(config)
+
+
+def do_upgrade_downgrade(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 = sign + str(CONF.command.delta)
+    else:
+        revision = CONF.command.revision
+
+    do_alembic_command(config, cmd, revision, sql=CONF.command.sql)
+
+
+def do_stamp(config, cmd):
+    do_alembic_command(config, cmd,
+                       CONF.command.revision,
+                       sql=CONF.command.sql)
+
+
+def do_revision(config, cmd):
+    do_alembic_command(config, cmd,
+                       message=CONF.command.message,
+                       autogenerate=CONF.command.autogenerate,
+                       sql=CONF.command.sql)
+    update_head_file(config)
+
+
+def validate_head_file(config):
+    script = alembic_script.ScriptDirectory.from_config(config)
+    if len(script.get_heads()) > 1:
+        alembic_util.err(_('Timeline branches unable to generate timeline'))
+
+    head_path = os.path.join(script.versions, HEAD_FILENAME)
+    current_head = script.get_current_head()
+    if os.path.isfile(head_path):
+        head_in_file = open(head_path).read().strip()
+        if current_head == head_in_file:
+            return
+    else:
+        alembic_util.err(_('HEAD file does not match migration timeline head'))
+
+
+def update_head_file(config):
+    script = alembic_script.ScriptDirectory.from_config(config)
+    if len(script.get_heads()) > 1:
+        alembic_util.err(_('Timeline branches unable to generate timeline'))
+
+    head_path = os.path.join(script.versions, HEAD_FILENAME)
+    with open(head_path, 'w+') as f:
+        f.write(script.get_current_head())
+
+
+def add_command_parsers(subparsers):
+    for name in ['current', 'history', 'branches']:
+        parser = subparsers.add_parser(name)
+        parser.set_defaults(func=do_alembic_command)
+
+    parser = subparsers.add_parser('check_migration')
+    parser.set_defaults(func=do_check_migration)
+
+    for name in ['upgrade', 'downgrade']:
+        parser = subparsers.add_parser(name)
+        parser.add_argument('--delta', type=int)
+        parser.add_argument('--sql', action='store_true')
+        parser.add_argument('revision', nargs='?')
+        parser.add_argument('--mysql-engine',
+                            default='',
+                            help='Change MySQL storage engine of current '
+                                 'existing tables')
+        parser.set_defaults(func=do_upgrade_downgrade)
+
+    parser = subparsers.add_parser('stamp')
+    parser.add_argument('--sql', action='store_true')
+    parser.add_argument('revision')
+    parser.set_defaults(func=do_stamp)
+
+    parser = subparsers.add_parser('revision')
+    parser.add_argument('-m', '--message')
+    parser.add_argument('--autogenerate', action='store_true')
+    parser.add_argument('--sql', action='store_true')
+    parser.set_defaults(func=do_revision)
+
+
+command_opt = cfg.SubCommandOpt('command',
+                                title='Command',
+                                help=_('Available commands'),
+                                handler=add_command_parsers)
+
+CONF.register_cli_opt(command_opt)
+
+
+def main():
+    config = alembic_config.Config(
+        os.path.join(os.path.dirname(__file__), 'alembic.ini')
+    )
+    config.set_main_option('script_location',
+                           'powervc.neutron.db.migration:alembic_migration')
+    # attach the Neutron conf to the Alembic conf
+    config.powervc_config = CONF
+
+    CONF()
+
+    CONF.command.func(config, CONF.command.name)

neutron-powervc/powervc/neutron/db/powervc_db_v2.py

@@ -1,5 +1,6 @@
-# Copyright 2013 IBM Corp.
+# Copyright 2013, 2014 IBM Corp.
 
+import sqlalchemy as sql
 from sqlalchemy.orm import exc
 
 import neutron.db.api as db_api
@@ -18,7 +19,15 @@ class PowerVCAgentDB(object):
 
     def __init__(self):
         self.session = db_api.get_session()
-        db_api.configure_db()
+        self.register_models()
+
+    def register_models(self):
+        """Register Models and create properties."""
+        try:
+            engine = db_api.get_engine()
+            model.PowerVCMapping.metadata.create_all(engine)
+        except sql.exc.OperationalError as e:
+            LOG.info(_("Database registration exception: %s"), e)
 
     def _create_object(self, obj_type, sync_key, update_data=None,
                        local_id=None, pvc_id=None):