Add request/response logging when debug=True

* print headers/environ of request and response
* print bodies of request and response

Here is an example of output: https://gist.github.com/Frostman/5879730

Change-Id: I4a5777962d5cb397f1478ac0f04fb380fbdc1285

openstack-common.conf

@@ -1,5 +1,5 @@
 [DEFAULT]
-modules=setup, jsonutils, xmlutils, timeutils, exception, gettextutils, log, local, notifier/api, notifier/log_notifier, notifier/no_op_notifier, notifier/test_notifier, notifier/__init__, importutils, context, uuidutils, version, threadgroup, db, db.sqlalchemy, excutils, cfgfilter
+modules=setup, jsonutils, xmlutils, timeutils, exception, gettextutils, log, local, notifier/api, notifier/log_notifier, notifier/no_op_notifier, notifier/test_notifier, notifier/__init__, importutils, context, uuidutils, version, threadgroup, db, db.sqlalchemy, excutils, cfgfilter,middleware.base, middleware.debug
 base=savanna
 
 # The following code from 'wsgi' is needed:

savanna/main.py

@@ -23,6 +23,7 @@ from savanna.api import v10 as api_v10
 from savanna import context
 from savanna.db import api as db_api
 from savanna.middleware import auth_valid
+from savanna.openstack.common.middleware import debug
 from savanna.plugins import base as plugins_base
 from savanna.utils import api as api_utils
 from savanna.utils import scheduler
@@ -110,6 +111,9 @@ def make_app():
     for code in werkzeug_exceptions.default_exceptions.iterkeys():
         app.error_handler_spec[None][code] = make_json_error
 
+    if CONF.debug:
+        app.wsgi_app = debug.Debug.factory(app.config)(app.wsgi_app)
+
     app.wsgi_app = auth_valid.filter_factory(app.config)(app.wsgi_app)
 
     app.wsgi_app = auth_token.filter_factory(

savanna/openstack/common/middleware/base.py

@@ -0,0 +1,59 @@
+# 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."""
+
+        def filter(app):
+            return cls(app)
+
+        return filter
+
+    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)

savanna/openstack/common/middleware/debug.py

@@ -0,0 +1,58 @@
+# 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.
+"""Debug middleware"""
+
+from __future__ import print_function
+
+import sys
+
+import webob.dec
+
+from savanna.openstack.common.middleware import base
+
+
+class Debug(base.Middleware):
+    """Helper class that returns debug information.
+
+    Can be inserted into any WSGI application chain to get information about
+    the request and response.
+    """
+
+    @webob.dec.wsgify
+    def __call__(self, req):
+        print(("*" * 40) + " REQUEST ENVIRON")
+        for key, value in req.environ.items():
+            print(key, "=", value)
+        print()
+        resp = req.get_response(self.application)
+
+        print(("*" * 40) + " RESPONSE HEADERS")
+        for (key, value) in resp.headers.iteritems():
+            print(key, "=", value)
+        print()
+
+        resp.app_iter = self.print_generator(resp.app_iter)
+
+        return resp
+
+    @staticmethod
+    def print_generator(app_iter):
+        """Prints the contents of a wrapper string iterator when iterated."""
+        print(("*" * 40) + " BODY")
+        for part in app_iter:
+            sys.stdout.write(part)
+            sys.stdout.flush()
+            yield part
+        print()