Install and configure for Red Hat Enterprise Linux and CentOS in magnum

[Kishor Kumar Das]

Magnun DB Sync Error on OpenStack Queens on CentOS 7.

su -s /bin/sh -c "magnum-db-manage upgrade" magnum
Traceback (most recent call last):
  File "/usr/bin/magnum-db-manage", line 10, in <module>
    sys.exit(main())
  File "/usr/lib/python2.7/site-packages/magnum/cmd/db_manage.py", line 69, in main
    CONF.command.func()
  File "/usr/lib/python2.7/site-packages/magnum/cmd/db_manage.py", line 29, in do_upgrade
    migration.upgrade(CONF.command.revision)
  File "/usr/lib/python2.7/site-packages/magnum/db/migration.py", line 37, in upgrade
    return get_backend().upgrade(version)
  File "/usr/lib/python2.7/site-packages/magnum/db/migration.py", line 31, in get_backend
    CONF.database.backend).driver
  File "/usr/lib/python2.7/site-packages/stevedore/driver.py", line 61, in __init__
    warn_on_missing_entrypoint=warn_on_missing_entrypoint
  File "/usr/lib/python2.7/site-packages/stevedore/named.py", line 89, in __init__
    self._init_plugins(extensions)
  File "/usr/lib/python2.7/site-packages/stevedore/driver.py", line 113, in _init_plugins
    (self.namespace, name))
stevedore.exception.NoMatches: No 'magnum.database.migration_backend' driver found, looking for 'sqlalchemy'

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-----------------------------------
Release: 6.1.1.dev17 on 2018-05-02 09:46
SHA: 197382de3b110410cea9c4e430df27f9053641cc
Source: https://git.openstack.org/cgit/openstack/magnum/tree/doc/source/install/install-rdo.rst
URL: https://docs.openstack.org/magnum/queens/install/install-rdo.html