Use oslo.middleware instead of copy-pasted

Related-Bug:#1380725
Change-Id: I3f4ea433f4cf78080ba97f9fa6eec22bc1ef21a3

openstack-common.conf

@@ -6,7 +6,6 @@ module=excutils
 module=importutils
 module=lockutils
 module=log
-module=middleware.base
 module=periodic_task
 module=processutils
 module=strutils

requirements.txt

@@ -16,6 +16,7 @@ oslo.config>=1.4.0  # Apache-2.0
 oslo.db>=1.0.0  # Apache-2.0
 oslo.i18n>=1.0.0  # Apache-2.0
 oslo.messaging>=1.4.0
+oslo.middleware>=0.1.0                  # Apache-2.0
 oslo.rootwrap>=1.3.0
 oslo.serialization>=1.0.0               # Apache-2.0
 oslo.utils>=1.0.0                       # Apache-2.0

sahara/api/middleware/log_exchange.py

@@ -20,10 +20,9 @@
 from __future__ import print_function
 import sys
 
+from oslo.middleware import base
 import webob.dec
 
-from sahara.openstack.common.middleware import base
-
 
 class LogExchange(base.Middleware):
     """Helper class that returns debug information.

sahara/openstack/common/middleware/base.py

@@ -1,56 +0,0 @@
-# Copyright 2011 OpenStack Foundation.
-# All Rights Reserved.
-#
-#    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.
-
-"""Base class(es) for WSGI Middleware."""
-
-import webob.dec
-
-
-class Middleware(object):
-    """Base WSGI middleware wrapper.
-
-    These classes require an application to be initialized that will be called
-    next.  By default the middleware will simply call its wrapped app, or you
-    can override __call__ to customize its behavior.
-    """
-
-    @classmethod
-    def factory(cls, global_conf, **local_conf):
-        """Factory method for paste.deploy."""
-        return cls
-
-    def __init__(self, application):
-        self.application = application
-
-    def process_request(self, req):
-        """Called on each request.
-
-        If this returns None, the next application down the stack will be
-        executed. If it returns a response then that response will be returned
-        and execution will stop here.
-        """
-        return None
-
-    def process_response(self, response):
-        """Do whatever you'd like to the response."""
-        return response
-
-    @webob.dec.wsgify
-    def __call__(self, req):
-        response = self.process_request(req)
-        if response:
-            return response
-        response = req.get_response(self.application)
-        return self.process_response(response)