Sync oslo-incubator.middleware module

This syncing has contained oslo-incubator.middleware module
to get capability of x-openstack-request-id.

Change-Id: I8e3b7d23bc1def705a0399bbd5015241a0fba8b1
Partial-Bug: #1324065

heat/openstack/common/middleware/base.py

@@ -0,0 +1,56 @@
+# 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)

heat/openstack/common/middleware/request_id.py

@@ -0,0 +1,41 @@
+# Copyright (c) 2013 NEC Corporation
+# 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.
+
+"""Middleware that ensures request ID.
+
+It ensures to assign request ID for each API request and set it to
+request environment. The request ID is also added to API response.
+"""
+
+import webob.dec
+
+from heat.openstack.common import context
+from heat.openstack.common.middleware import base
+
+
+ENV_REQUEST_ID = 'openstack.request_id'
+HTTP_RESP_HEADER_REQUEST_ID = 'x-openstack-request-id'
+
+
+class RequestIdMiddleware(base.Middleware):
+
+    @webob.dec.wsgify
+    def __call__(self, req):
+        req_id = context.generate_request_id()
+        req.environ[ENV_REQUEST_ID] = req_id
+        response = req.get_response(self.application)
+        if HTTP_RESP_HEADER_REQUEST_ID not in response.headers:
+            response.headers.add(HTTP_RESP_HEADER_REQUEST_ID, req_id)
+        return response

openstack-common.conf

@@ -27,6 +27,7 @@ module=threadgroup
 module=timeutils
 module=uuidutils
 module=versionutils
+module=middleware
 
 # The base module to hold the copy of openstack.common
 base=heat