new_contents: # -*- coding: utf-8 -*-
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  # http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  from __future__ import unicode_literals
  
  from sys import version_info
  
  import flask_login
  from flask_login import login_required, current_user, logout_user
  
  from airflow import settings
  from airflow import models
  from airflow.utils.log.logging_mixin import LoggingMixin
  import os
  
  log = LoggingMixin().log
  
  class AuthenticationError(Exception):    
          pass
  
  class ProxiedUser(models.User):
      def __init__(self, user):
          self.user = user
  
      def is_active(self):
          '''Required by flask_login'''
          return True
  
      def is_authenticated(self):
          '''Required by flask_login'''
          return True
  
      def is_anonymous(self):
          '''Required by flask_login'''
          return False
          
      def get_id(self):
          '''Returns the current user id as required by flask_login'''
          return self.user.get_id()
  
      def data_profiling(self):
          '''Provides access to data profiling tools'''
          return True
  
      def is_superuser(self):
          '''Access all the things'''
          return True
  
  class ProxiedAuth(object):
      def __init__(self):
          self.login_manager = flask_login.LoginManager()
  
      def init_app(self,flask_app):
          self.flask_app = flask_app
          self.login_manager.init_app(self.flask_app)
  
          #checks headers instead of cookies
          self.login_manager.request_loader(self.load_request)
  
          # this is needed to disable the anti forgery check 
          flask_app.config['WTF_CSRF_CHECK_DEFAULT'] = False
      
      def load_request(self, request):
          '''
          Reads the header field that has already been verified on the
          nginx side by google auth. Header field is specified by setting
          the environment variable AIRFLOW_PROXIED_AUTH_HEADER or else
          it's defaulted to X-Email.
  
          '''
          session = settings.Session()
          header_field = os.getenv('AIRFLOW_PROXIED_AUTH_HEADER', 'X-Email')
          user_email = request.headers.get(header_field)
  
          # this shouldn't happen since nginx should take care of it!
          if user_email is None:
              raise AuthenticationError(
                    'Airflow failed to get google verified email ({0})'.format(
                    resp.status if resp else 'None'))
  
          # insert user into database if doesn't exist
          user = session.query(models.User).filter(
              models.User.username == user_email).first()
  
          if not user:
              user = models.User(
                  username=user_email,
                  is_superuser=True)
  
          session.merge(user)
          session.commit()
          session.close()
  
          return ProxiedUser(user)
  
  login_manager = ProxiedAuth()
  
  
  
subject: Add proxied auth