Add feature flag to disable username confirmation

Fixes https://jira.coreos.com/browse/QUAY-914

util/config/configutil.py

@@ -22,6 +22,7 @@ def add_enterprise_config_defaults(config_obj, current_secret_key, hostname):
   config_obj['FEATURE_DIRECT_LOGIN'] = config_obj.get('FEATURE_DIRECT_LOGIN', True)
   config_obj['FEATURE_APP_SPECIFIC_TOKENS'] = config_obj.get('FEATURE_APP_SPECIFIC_TOKENS', True)
   config_obj['FEATURE_PARTIAL_USER_AUTOCOMPLETE'] = config_obj.get('FEATURE_PARTIAL_USER_AUTOCOMPLETE', True)
+  config_obj['FEATURE_USERNAME_CONFIRMATION'] = config_obj.get('FEATURE_USERNAME_CONFIRMATION', True)
 
   # Default features that are off.
   config_obj['FEATURE_MAILING'] = config_obj.get('FEATURE_MAILING', False)

util/config/schema.py

@@ -909,6 +909,13 @@ CONFIG_SCHEMA = {
       'description': 'If set to true, users can rename their own namespace. Defaults to False',
       'x-example': True,
     },
+
+    # Feature Flag: Username confirmation.
+    'FEATURE_USERNAME_CONFIRMATION': {
+      'type': 'boolean',
+      'description': 'If set to true, users can confirm their generated usernames. Defaults to True',
+      'x-example': False,
+    },
  },
 }