neutron-db-manage fails during undercloud install with DefaultValueError

Issue

• During a Undercloud install, the installer fails with multiple services reporting errors similar to:

INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns: Traceback (most recent call last):
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/bin/neutron-db-manage", line 10, in <module>
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     sys.exit(main())
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/neutron/db/migration/cli.py", line 687, in main
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     return_val |= bool(CONF.command.func(config, CONF.command.name))
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/neutron/db/migration/cli.py", line 206, in do_upgrade 
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     run_sanity_checks(config, revision)
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/neutron/db/migration/cli.py", line 671, in run_sanity_checks
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     script_dir.run_env()    
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/alembic/script/base.py", line 416, in run_env
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     util.load_python_file(self.dir, 'env.py')
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/alembic/util/pyfiles.py", line 93, in load_python_file 
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     module = load_module_py(module_id, path)
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/alembic/util/compat.py", line 79, in load_module_py
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     mod = imp.load_source(module_id, path, fp)
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/neutron/db/migration/alembic_migrations/env.py", line 24, in <module>
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     from neutron.db.migration.models import head  # noqa
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/neutron/db/migration/models/head.py", line 29, in <module>
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     from neutron.db import agentschedulers_db  # noqa
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/neutron/db/agentschedulers_db.py", line 30, in <module>
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     from neutron.agent.common import utils as agent_utils
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/neutron/agent/common/utils.py", line 23, in <module>
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     from neutron.conf.agent import common as config 
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/neutron/conf/agent/common.py", line 23, in <module>
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     from neutron.common import config
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/neutron/common/config.py", line 31, in <module>
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     from neutron.conf import common as common_config 
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/neutron/conf/common.py", line 96, in <module>
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     help=_("Hostname to be used by the Neutron server, "
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/oslo_config/cfg.py", line 1488, in __init__
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     **kwargs)
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/oslo_config/cfg.py", line 963, in __init__
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     self._check_default()   
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:   File "/usr/lib/python2.7/site-packages/oslo_config/cfg.py", line 984, in _check_default
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns:     'opt': self.type})
INFO: Notice: /Stage[main]/Neutron::Db::Sync/Exec[neutron-db-sync]/returns: oslo_config.cfg.DefaultValueError: Error processing default value rh10_director.example.com for Opt type of HostAddress.