Mistral config guide has wrong DB connection URL

Mistral config guide instructs to install python-mysqldb driver for MySQL based databases. But, corresponding DB url conf has mysql+pymysql driver. This causes mistral-server process to crash as soon as it is launched.

$ pip install mysql-python

Configure connection in Mistral config:

[database]
connection = mysql+pymysql://<user>:<password>@<database-host>:3306/mistral

This page has several grammatical errors too.

Link: https://docs.openstack.org/mistral/latest/configuration/config-guide.html

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  16770 2018-04-10 17:25:59.852 14498 CRITICAL Mistral [-] Unhandled error: ImportError: No module named pymysql
  16771 2018-04-10 17:25:59.852 14498 ERROR Mistral Traceback (most recent call last):
  16772 2018-04-10 17:25:59.852 14498 ERROR Mistral File "/home/cbuser/projects/mistral/mistral/cmd/launch.py", line 240, in <module>
  16773 2018-04-10 17:25:59.852 14498 ERROR Mistral sys.exit(main())
  16774 2018-04-10 17:25:59.852 14498 ERROR Mistral File "/home/cbuser/projects/mistral/mistral/cmd/launch.py", line 212, in main
  16775 2018-04-10 17:25:59.852 14498 ERROR Mistral launch_any(set(cfg.CONF.server))
  16776 2018-04-10 17:25:59.852 14498 ERROR Mistral File "/home/cbuser/projects/mistral/mistral/cmd/launch.py", line 109, in launch_any
  16777 2018-04-10 17:25:59.852 14498 ERROR Mistral LAUNCH_OPTIONS[option]()
  16778 2018-04-10 17:25:59.852 14498 ERROR Mistral File "/home/cbuser/projects/mistral/mistral/cmd/launch.py", line 103, in launch_api
  16779 2018-04-10 17:25:59.852 14498 ERROR Mistral server = api_service.WSGIService('mistral_api')
  16780 2018-04-10 17:25:59.852 14498 ERROR Mistral File "/home/cbuser/projects/mistral/mistral/api/service.py", line 29, in __init__
  16781 2018-04-10 17:25:59.852 14498 ERROR Mistral self.app = app.setup_app()
  16782 2018-04-10 17:25:59.852 14498 ERROR Mistral File "/home/cbuser/projects/mistral/mistral/api/app.py", line 54, in setup_app
  16783 2018-04-10 17:25:59.852 14498 ERROR Mistral db_api_v2.setup_db()
  16784 2018-04-10 17:25:59.852 14498 ERROR Mistral File "/home/cbuser/projects/mistral/mistral/db/v2/api.py", line 29, in setup_db
  16785 2018-04-10 17:25:59.852 14498 ERROR Mistral IMPL.setup_db()
  16786 2018-04-10 17:25:59.852 14498 ERROR Mistral File "/home/cbuser/projects/mistral/mistral/db/v2/sqlalchemy/api.py", line 69, in setup_db
  16787 2018-04-10 17:25:59.852 14498 ERROR Mistral models.Workbook.metadata.create_all(b.get_engine())
  16788 2018-04-10 17:25:59.852 14498 ERROR Mistral File "/home/cbuser/projects/mistral/mistral/db/sqlalchemy/base.py", line 78, in get_engine
  16789 2018-04-10 17:25:59.852 14498 ERROR Mistral return _get_facade().get_engine()
  16790 2018-04-10 17:25:59.852 14498 ERROR Mistral File "/home/cbuser/projects/mistral/mistral/db/sqlalchemy/base.py", line 45, in _get_facade
  16791 2018-04-10 17:25:59.852 14498 ERROR Mistral **dict(cfg.CONF.database.items())
  16792 2018-04-10 17:25:59.852 14498 ERROR Mistral File "/home/cbuser/projects/mistral/.tox/py27/local/lib/python2.7/site-packages/oslo_db/sqlalchemy/enginefacade.py", line 126 16792 1, in __init__
  16793 2018-04-10 17:25:59.852 14498 ERROR Mistral slave_connection=slave_connection)
  16794 2018-04-10 17:25:59.852 14498 ERROR Mistral File "/home/cbuser/projects/mistral/.tox/py27/local/lib/python2.7/site-packages/oslo_db/sqlalchemy/enginefacade.py", line 495 16794 , in _start
  16795 2018-04-10 17:25:59.852 14498 ERROR Mistral engine_args, maker_args)
  16796 2018-04-10 17:25:59.852 14498 ERROR Mistral File "/home/cbuser/projects/mistral/.tox/py27/local/lib/python2.7/site-packages/oslo_db/sqlalchemy/enginefacade.py", line 519 16796 , in _setup_for_connection
  16797 2018-04-10 17:25:59.852 14498 ERROR Mistral sql_connection=sql_connection, **engine_kwargs)
  16798 2018-04-10 17:25:59.852 14498 ERROR Mistral File "/home/cbuser/projects/mistral/.tox/py27/local/lib/python2.7/site-packages/debtcollector/renames.py", line 43, in decora 16798 tor
  16799 2018-04-10 17:25:59.852 14498 ERROR Mistral return wrapped(*args, **kwargs)
  16800 2018-04-10 17:25:59.852 14498 ERROR Mistral File "/home/cbuser/projects/mistral/.tox/py27/local/lib/python2.7/site-packages/oslo_db/sqlalchemy/engines.py", line 178, in 16800 create_engine
  16801 2018-04-10 17:25:59.852 14498 ERROR Mistral engine = sqlalchemy.create_engine(url, **engine_args)
  16802 2018-04-10 17:25:59.852 14498 ERROR Mistral File "/home/cbuser/projects/mistral/mistral/db/sqlalchemy/base.py", line 69, in _sqlalchemy_create_engine_wrapper
  16803 2018-04-10 17:25:59.852 14498 ERROR Mistral return _sqlalchemy_create_engine_orig(*args, **kwargs)
  16804 2018-04-10 17:25:59.852 14498 ERROR Mistral File "/home/cbuser/projects/mistral/.tox/py27/local/lib/python2.7/site-packages/sqlalchemy/engine/__init__.py", line 424, in 16804 create_engine
  16805 2018-04-10 17:25:59.852 14498 ERROR Mistral return strategy.create(*args, **kwargs)
  16806 2018-04-10 17:25:59.852 14498 ERROR Mistral File "/home/cbuser/projects/mistral/.tox/py27/local/lib/python2.7/site-packages/sqlalchemy/engine/strategies.py", line 81, in 16806 create
  16807 2018-04-10 17:25:59.852 14498 ERROR Mistral dbapi = dialect_cls.dbapi(**dbapi_args)
  16808 2018-04-10 17:25:59.852 14498 ERROR Mistral File "/home/cbuser/projects/mistral/.tox/py27/local/lib/python2.7/site-packages/sqlalchemy/dialects/mysql/pymysql.py", line 6 16808 2, in dbapi
  16809 2018-04-10 17:25:59.852 14498 ERROR Mistral return __import__('pymysql')
  16810 2018-04-10 17:25:59.852 14498 ERROR Mistral ImportError: No module named pymysql