database migration 009 fails on Centos ('Can't DROP 'cron_triggers_v2_workflow_input_hash_workflow_name_pattern__key')

[Dan Prince]

INFO [alembic.runtime.migration] Running upgrade 008 -> 009, Add database indices
Traceback (most recent call last):
  File "/usr/bin/mistral-db-manage", line 10, in <module>
    sys.exit(main())
  File "/usr/lib/python2.7/site-packages/mistral/db/sqlalchemy/migration/cli.py", line 129, in main
    CONF.command.func(config, CONF.command.name)
  File "/usr/lib/python2.7/site-packages/mistral/db/sqlalchemy/migration/cli.py", line 58, in do_upgrade
    do_alembic_command(config, cmd, revision, sql=CONF.command.sql)
  File "/usr/lib/python2.7/site-packages/mistral/db/sqlalchemy/migration/cli.py", line 39, in do_alembic_command
    getattr(alembic_cmd, cmd)(config, *args, **kwargs)
  File "/usr/lib/python2.7/site-packages/alembic/command.py", line 174, in upgrade
    script.run_env()
  File "/usr/lib/python2.7/site-packages/alembic/script/base.py", line 397, in run_env
    util.load_python_file(self.dir, 'env.py')
  File "/usr/lib/python2.7/site-packages/alembic/util/pyfiles.py", line 81, in load_python_file
    module = load_module_py(module_id, path)
  File "/usr/lib/python2.7/site-packages/alembic/util/compat.py", line 79, in load_module_py
    mod = imp.load_source(module_id, path, fp)
  File "/usr/lib/python2.7/site-packages/mistral/db/sqlalchemy/migration/alembic_migrations/env.py", line 86, in <module>
    run_migrations_online()
  File "/usr/lib/python2.7/site-packages/mistral/db/sqlalchemy/migration/alembic_migrations/env.py", line 78, in run_migrations_online
    context.run_migrations()
  File "<string>", line 8, in run_migrations
  File "/usr/lib/python2.7/site-packages/alembic/runtime/environment.py", line 797, in run_migrations
    self.get_context().run_migrations(**kw)
  File "/usr/lib/python2.7/site-packages/alembic/runtime/migration.py", line 312, in run_migrations
    step.migration_fn(**kw)
  File "/usr/lib/python2.7/site-packages/mistral/db/sqlalchemy/migration/alembic_migrations/versions/009_add_database_indices.py", line 91, in upgrade
    type_='unique'
  File "<string>", line 8, in drop_constraint
  File "<string>", line 3, in drop_constraint
  File "/usr/lib/python2.7/site-packages/alembic/operations/ops.py", line 145, in drop_constraint
    return operations.invoke(op)
  File "/usr/lib/python2.7/site-packages/alembic/operations/base.py", line 318, in invoke
    return fn(self, operation)
  File "/usr/lib/python2.7/site-packages/alembic/operations/toimpl.py", line 146, in drop_constraint
    schema=operation.schema,
  File "/usr/lib/python2.7/site-packages/alembic/ddl/impl.py", line 183, in drop_constraint
    self._exec(schema.DropConstraint(const))
  File "/usr/lib/python2.7/site-packages/alembic/ddl/impl.py", line 118, in _exec
    return conn.execute(construct, *multiparams, **params)
  File "/usr/lib64/python2.7/site-packages/sqlalchemy/engine/base.py", line 914, in execute
    return meth(self, multiparams, params)
  File "/usr/lib64/python2.7/site-packages/sqlalchemy/sql/ddl.py", line 68, in _execute_on_connection
    return connection._execute_ddl(self, multiparams, params)
  File "/usr/lib64/python2.7/site-packages/sqlalchemy/engine/base.py", line 968, in _execute_ddl
    compiled
  File "/usr/lib64/python2.7/site-packages/sqlalchemy/engine/base.py", line 1146, in _execute_context
    context)
  File "/usr/lib64/python2.7/site-packages/sqlalchemy/engine/base.py", line 1339, in _handle_dbapi_exception
    exc_info
  File "/usr/lib64/python2.7/site-packages/sqlalchemy/util/compat.py", line 199, in raise_from_cause
    reraise(type(exception), exception, tb=exc_tb)
  File "/usr/lib64/python2.7/site-packages/sqlalchemy/engine/base.py", line 1139, in _execute_context
    context)
  File "/usr/lib64/python2.7/site-packages/sqlalchemy/engine/default.py", line 442, in do_execute
    cursor.execute(statement, parameters)
  File "/usr/lib64/python2.7/site-packages/MySQLdb/cursors.py", line 174, in execute
    self.errorhandler(self, exc, value)
  File "/usr/lib64/python2.7/site-packages/MySQLdb/connections.py", line 36, in defaulterrorhandler
    raise errorclass, errorvalue
sqlalchemy.exc.OperationalError: (_mysql_exceptions.OperationalError) (1091, "Can't DROP 'cron_triggers_v2_workflow_input_hash_workflow_name_pattern__key'; check that column/key exists") [SQL: u'ALTER TABLE cron_triggers_v2 DROP INDEX cron_triggers_v2_workflow_input_hash_workflow_name_pattern__key']

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/258080

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/258080
Committed: https://git.openstack.org/cgit/openstack/mistral/commit/?id=828228da128a59cf94e554392f0a2faeb7da3ba5
Submitter: Jenkins
Branch: master

commit 828228da128a59cf94e554392f0a2faeb7da3ba5
Author: Dan Prince <email address hidden>
Date: Tue Dec 15 13:32:53 2015 -0500

    Fix DB migration 009 constraint dropping

    Database migration 009 fails to run on Centos with errors
    about indexes not existing. This occurs on a fresh installation
    where no previous data, etc. The indexes being dropped in migration
    009 were likely automatically added by some other MySQL
    version/distribution so to support both cases we add a simple
    check to ensure the index exists before attempting to drop it.

    Change-Id: Ib6d848c1e32bbab6fdb7e30009f5c5f907fd8477
    Closes-bug: #1526463