old_contents: # -*- coding: utf-8 -*-
  # vim: tabstop=4 shiftwidth=4 softtabstop=4
  
  # Copyright (c) 2015, GEM Foundation.
  #
  # OpenQuake is free software: you can redistribute it and/or modify it
  # under the terms of the GNU Affero General Public License as published
  # by the Free Software Foundation, either version 3 of the License, or
  # (at your option) any later version.
  #
  # OpenQuake is distributed in the hope that it will be useful,
  # but WITHOUT ANY WARRANTY; without even the implied warranty of
  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  # GNU General Public License for more details.
  #
  # You should have received a copy of the GNU Affero General Public License
  # along with OpenQuake.  If not, see <http://www.gnu.org/licenses/>.
  
  
  '''
  Database routers for the OpenQuake engine server authenticaton DB
  '''
  
  
  class AuthRouter(object):
      """
      A router to control all database operations on models in the
      auth application.
      """
      def db_for_read(self, model, **hints):
          """
          Attempts to read auth models go to auth_db.
          """
          if (model._meta.app_label == 'auth' or
                  model._meta.app_label == 'sessions' or
                  model._meta.app_label == 'admin'):
              return 'auth_db'
          return None
  
      def db_for_write(self, model, **hints):
          """
          Attempts to write auth models go to auth_db.
          """
          if (model._meta.app_label == 'auth' or
                  model._meta.app_label == 'sessions' or
                  model._meta.app_label == 'admin'):
              return 'auth_db'
          return None
  
      def allow_relation(self, obj1, obj2, **hints):
          """
          Allow relations if a model in the auth app is involved.
          """
          if obj1._meta.app_label == 'auth' or \
             obj2._meta.app_label == 'auth':
                  return True
          return None
  
      def allow_migrate(self, db, app_label, model=None, **hints):
          """
          Make sure the auth app only appears in the 'auth_db'
          database.
          """
          if (app_label == 'auth' or
                  app_label == 'sessions' or
                  app_label == 'admin'):
              return db == 'auth_db'
          return None
  
new_contents: # -*- coding: utf-8 -*-
  # vim: tabstop=4 shiftwidth=4 softtabstop=4
  
  # Copyright (c) 2015, GEM Foundation.
  #
  # OpenQuake is free software: you can redistribute it and/or modify it
  # under the terms of the GNU Affero General Public License as published
  # by the Free Software Foundation, either version 3 of the License, or
  # (at your option) any later version.
  #
  # OpenQuake is distributed in the hope that it will be useful,
  # but WITHOUT ANY WARRANTY; without even the implied warranty of
  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  # GNU General Public License for more details.
  #
  # You should have received a copy of the GNU Affero General Public License
  # along with OpenQuake.  If not, see <http://www.gnu.org/licenses/>.
  
  
  '''
  Database routers for the OpenQuake engine server authenticaton DB
  '''
  
  APPS = (
      'auth',
      'contenttypes',
      'sessions',
      'sites',
      'admin',
  )
  
  
  class AuthRouter(object):
      """
      A router to control all database operations on models in the
      auth application.
      """
      def db_for_read(self, model, **hints):
          """
          Attempts to read auth models go to auth_db.
          """
          if model._meta.app_label in APPS:
              return 'auth_db'
          return None
  
      def db_for_write(self, model, **hints):
          """
          Attempts to write auth models go to auth_db.
          """
          if model._meta.app_label in APPS:
              return 'auth_db'
          return None
  
subject: Refactor engine server router.py