docs: def auth_user_remote_user(self, username):
          """
              REMOTE_USER user Authentication
  
              :param username: user's username for remote auth
              :type self: User model
          """
          user = self.find_user(username=username)
  
          # User does not exist, create one if auto user registration.
          if user is None and self.auth_user_registration:
              user = self.add_user(
                  # All we have is REMOTE_USER, so we set
                  # the other fields to blank.
                  username=username,
                  first_name=username,
                  last_name="-",
                  email="-",
                  role=self.find_role(self.auth_user_registration_role),
              )
  
          # If user does not exist on the DB and not auto user registration,
          # or user is inactive, go away.
          elif user is None or (not user.is_active):
              log.info(LOGMSG_WAR_SEC_LOGIN_FAILED.format(username))
              return None
  
          self.update_user_auth_stat(user)
          return user