Remove unused placement_database config options

The placement_database config options were added in Newton
but the actual code to use the options was reverted and is
not used. The help text actually has a typo (Ocata was 15.0.0,
not 14.0.0) and, more importantly, the help text makes it sound
like you should really be setting up a separate database for the
placement service but we don't actually use these options, we use
the api_database options for all of the placement data models.

To avoid confusion until this is actually supported, let's just
remove the options which should have been cleaned up as part of
39fb302fd9 anyway.

Conflicts:
        nova/tests/functional/api/openstack/placement/fixtures.py

NOTE(mriedem): The conflict is due to not having change
a598af9de6 in stable/ocata.

Change-Id: I31293ac4689630e4113588ab2c6373cf572b8f38
Closes-Bug: #1670419
(cherry picked from commit 7439e94736)

nova/conf/database.py

@@ -112,64 +112,11 @@ def enrich_help_text(alt_db_opts):
                 # texts here if needed.
                 alt_db_opt.help = db_opt.help + alt_db_opt.help
 
-# NOTE(cdent): See the note above on api_db_opts. The same issues
-# apply here.
-
-placement_db_group = cfg.OptGroup('placement_database',
-                                  title='Placement API database options',
-                                  help="""
-The *Placement API Database* is a separate database which is used for the new
-placement-api service. In Ocata release (14.0.0) this database is optional: if
-connection option is not set, api database will be used instead.  However, this
-is not recommended, as it implies a potentially lengthy data migration in the
-future. Operators are advised to use a separate database for Placement API from
-the start.
-""")
-
-# TODO(rpodolyaka): see the notes on help messages on api_db_opts above, those
-# also apply here
-placement_db_opts = [
-    cfg.StrOpt('connection',
-               help='',
-               secret=True),
-    cfg.BoolOpt('sqlite_synchronous',
-                default=True,
-                help=''),
-    cfg.StrOpt('slave_connection',
-               secret=True,
-               help=''),
-    cfg.StrOpt('mysql_sql_mode',
-               default='TRADITIONAL',
-               help=''),
-    cfg.IntOpt('idle_timeout',
-               default=3600,
-               help=''),
-    cfg.IntOpt('max_pool_size',
-               help=''),
-    cfg.IntOpt('max_retries',
-               default=10,
-               help=''),
-    cfg.IntOpt('retry_interval',
-               default=10,
-               help=''),
-    cfg.IntOpt('max_overflow',
-               help=''),
-    cfg.IntOpt('connection_debug',
-               default=0,
-               help=''),
-    cfg.BoolOpt('connection_trace',
-                default=False,
-                help=''),
-    cfg.IntOpt('pool_timeout',
-               help=''),
-]  # noqa
-
 
 def register_opts(conf):
     oslo_db_options.set_defaults(conf, connection=_DEFAULT_SQL_CONNECTION)
     conf.register_opt(db_driver_opt)
     conf.register_opts(api_db_opts, group=api_db_group)
-    conf.register_opts(placement_db_opts, group=placement_db_group)
 
 
 def list_opts():
@@ -181,8 +128,6 @@ def list_opts():
     # in the "sample.conf" file, I omit the listing of the "oslo_db_options"
     # here.
     enrich_help_text(api_db_opts)
-    enrich_help_text(placement_db_opts)
     return {'DEFAULT': [db_driver_opt],
             api_db_group: api_db_opts,
-            placement_db_group: placement_db_opts,
             }

nova/tests/functional/api/openstack/placement/fixtures.py

@@ -53,8 +53,6 @@ class APIFixture(fixture.GabbiFixture):
         self.conf.set_override('connection', "sqlite://", group='database')
         self.conf.set_override('connection', "sqlite://",
                                group='api_database')
-        self.conf.set_override('connection', "sqlite://",
-                               group='placement_database')
         config.parse_args([], default_config_files=None, configure_db=False,
                           init_rpc=False)