Use config choices for replication_mode option

The oslo.config module permits using a choices parameter to specify
the list of valid values for a particular option.  The
replication_mode mode can utilize this parameter and allow the
removal of some validation checking code.

Change-Id: I77baec69717019664e71ae2fd24be8e1d908374b

vmware_nsx/common/config.py

@@ -74,6 +74,7 @@ base_opts = [
                deprecated_group='NVP',
                help=_("The mode used to implement DHCP/metadata services.")),
     cfg.StrOpt('replication_mode', default=ReplicationModes.SERVICE,
+               choices=(ReplicationModes.SERVICE, ReplicationModes.SOURCE),
                help=_("The default option leverages service nodes to perform"
                       " packet replication though one could set to this to "
                       "'source' to perform replication locally. This is useful"
@@ -345,14 +346,6 @@ cfg.CONF.register_opts(base_opts, group="NSX")
 cfg.CONF.register_opts(sync_opts, group="NSX_SYNC")
 
 
-def validate_config_options():
-    if cfg.CONF.NSX.replication_mode not in (ReplicationModes.SERVICE,
-                                             ReplicationModes.SOURCE):
-        error = (_("Invalid replication_mode: %s") %
-                 cfg.CONF.NSX.replication_mode)
-        raise nsx_exc.NsxPluginException(err_msg=error)
-
-
 def validate_nsxv_config_options():
     if (cfg.CONF.nsxv.manager_uri is None or
         cfg.CONF.nsxv.user is None or

vmware_nsx/plugins/dvs/plugin.py

@@ -78,7 +78,6 @@ class NsxDvsV2(addr_pair_db.AllowedAddressPairsMixin,
 
     def __init__(self):
         super(NsxDvsV2, self).__init__()
-        config.validate_config_options()
         LOG.debug('Driver support: DVS: %s' % dvs_utils.dvs_is_enabled())
         neutron_extensions.append_api_extensions_path(
             [vmware_nsx.NSX_EXT_PATH])

vmware_nsx/plugins/nsx_mh/plugin.py

@@ -134,7 +134,6 @@ class NsxPluginV2(addr_pair_db.AllowedAddressPairsMixin,
 
     def __init__(self):
         super(NsxPluginV2, self).__init__()
-        config.validate_config_options()
         # TODO(salv-orlando): Replace These dicts with
         # collections.defaultdict for better handling of default values
         # Routines for managing logical ports in NSX