Re-worked some of the WSGI and WSGIService code to make launching WSGI services easier, less error prone, and more testable. Added tests for WSGI server, new WSGI loader, and modified integration tests where needed.

18 files changed, 458 insertions, 237 deletions

diff --git a/bin/nova-ajax-console-proxy b/bin/nova-ajax-console-proxy
index d88f59e40..21cf68007 100755
--- a/bin/nova-ajax-console-proxy
+++ b/bin/nova-ajax-console-proxy
@@ -137,8 +137,9 @@ if __name__ == '__main__':
     utils.default_flagfile()
     FLAGS(sys.argv)
     logging.setup()
-    server = wsgi.Server()
+    acp_port = FLAGS.ajax_console_proxy_port
     acp = AjaxConsoleProxy()
     acp.register_listeners()
-    server.start(acp, FLAGS.ajax_console_proxy_port, host='0.0.0.0')
+    server = wsgi.Server("AJAX Console Proxy", acp, port=acp_port)
+    server.start()
     server.wait()
diff --git a/bin/nova-api b/bin/nova-api
index a1088c23d..ea99a1b48 100755
--- a/bin/nova-api
+++ b/bin/nova-api
@@ -1,5 +1,4 @@
 #!/usr/bin/env python
-# pylint: disable=C0103
 # vim: tabstop=4 shiftwidth=4 softtabstop=4
 
 # Copyright 2010 United States Government as represented by the
@@ -18,44 +17,34 @@
 #    See the License for the specific language governing permissions and
 #    limitations under the License.
 
-"""Starter script for Nova API."""
+"""Starter script for Nova API.
+
+Starts both the EC2 and OpenStack APIs in separate processes.
+
+"""
 
-import gettext
-import os
 import sys
 
-# If ../nova/__init__.py exists, add ../ to Python search path, so that
-# it will override what happens to be installed in /usr/(local/)lib/python...
-possible_topdir = os.path.normpath(os.path.join(os.path.abspath(sys.argv[0]),
-                                   os.pardir,
-                                   os.pardir))
-if os.path.exists(os.path.join(possible_topdir, 'nova', '__init__.py')):
-    sys.path.insert(0, possible_topdir)
+import nova.service
+import nova.utils
+
 
-gettext.install('nova', unicode=1)
+def main():
+    """Launch EC2 and OSAPI services."""
+    nova.utils.Bootstrapper.bootstrap_binary(sys.argv)
 
-from nova import flags
-from nova import log as logging
-from nova import service
-from nova import utils
-from nova import version
-from nova import wsgi
+    ec2 = nova.service.WSGIService("ec2")
+    osapi = nova.service.WSGIService("osapi")
 
+    launcher = nova.service.Launcher()
+    launcher.launch_service(ec2)
+    launcher.launch_service(osapi)
 
-LOG = logging.getLogger('nova.api')
+    try:
+        launcher.wait()
+    except KeyboardInterrupt:
+        launcher.stop()
 
-FLAGS = flags.FLAGS
 
 if __name__ == '__main__':
-    utils.default_flagfile()
-    FLAGS(sys.argv)
-    logging.setup()
-    LOG.audit(_("Starting nova-api node (version %s)"),
-              version.version_string_with_vcs())
-    LOG.debug(_("Full set of FLAGS:"))
-    for flag in FLAGS:
-        flag_get = FLAGS.get(flag, None)
-        LOG.debug("%(flag)s : %(flag_get)s" % locals())
-
-    service = service.serve_wsgi(service.ApiService)
-    service.wait()
+    sys.exit(main())
diff --git a/bin/nova-direct-api b/bin/nova-direct-api
index 83ec72722..c6cf9b2ff 100755
--- a/bin/nova-direct-api
+++ b/bin/nova-direct-api
@@ -93,6 +93,9 @@ if __name__ == '__main__':
     with_req = direct.PostParamsMiddleware(with_json)
     with_auth = direct.DelegatedAuthMiddleware(with_req)
 
-    server = wsgi.Server()
-    server.start(with_auth, FLAGS.direct_port, host=FLAGS.direct_host)
+    server = wsgi.Server("Direct API",
+                         with_auth,
+                         host=FLAGS.direct_host,
+                         port=FLAGS.direct_port)
+    server.start()
     server.wait()
diff --git a/bin/nova-objectstore b/bin/nova-objectstore
index 6ef841b85..1aef3a255 100755
--- a/bin/nova-objectstore
+++ b/bin/nova-objectstore
@@ -50,6 +50,9 @@ if __name__ == '__main__':
     FLAGS(sys.argv)
     logging.setup()
     router = s3server.S3Application(FLAGS.buckets_path)
-    server = wsgi.Server()
-    server.start(router, FLAGS.s3_port, host=FLAGS.s3_host)
+    server = wsgi.Server("S3 Objectstore",
+                         router,
+                         port=FLAGS.s3_port,
+                         host=FLAGS.s3_host)
+    server.start()
     server.wait()
diff --git a/bin/nova-vncproxy b/bin/nova-vncproxy
index ccb97e3a3..72271df3a 100755
--- a/bin/nova-vncproxy
+++ b/bin/nova-vncproxy
@@ -96,6 +96,9 @@ if __name__ == "__main__":
 
     service.serve()
 
-    server = wsgi.Server()
-    server.start(with_auth, FLAGS.vncproxy_port, host=FLAGS.vncproxy_host)
+    server = wsgi.Server("VNC Proxy",
+                         with_auth,
+                         host=FLAGS.vncproxy_host,
+                         port=FLAGS.vncproxy_port)
+    server.start()
     server.wait()
diff --git a/nova/__init__.py b/nova/__init__.py
index 256db55a9..884c4a713 100644
--- a/nova/__init__.py
+++ b/nova/__init__.py
@@ -30,3 +30,8 @@
 .. moduleauthor:: Manish Singh <yosh@gimp.org>
 .. moduleauthor:: Andy Smith <andy@anarkystic.com>
 """
+
+import gettext
+
+
+gettext.install("nova", unicode=1)
diff --git a/nova/api/openstack/wsgi.py b/nova/api/openstack/wsgi.py
index 5d24b4cca..5b6e3cb1d 100644
--- a/nova/api/openstack/wsgi.py
+++ b/nova/api/openstack/wsgi.py
@@ -358,7 +358,7 @@ class Resource(wsgi.Application):
     def __call__(self, request):
         """WSGI method that controls (de)serialization and method dispatch."""
 
-        LOG.debug("%(method)s %(url)s" % {"method": request.method,
+        LOG.info("%(method)s %(url)s" % {"method": request.method,
                                           "url": request.url})
 
         try:
@@ -386,7 +386,7 @@ class Resource(wsgi.Application):
             msg_dict = dict(url=request.url, e=e)
             msg = _("%(url)s returned a fault: %(e)s" % msg_dict)
 
-        LOG.debug(msg)
+        LOG.info(msg)
 
         return response
 
diff --git a/nova/exception.py b/nova/exception.py
index 79ae6561c..ef50b144f 100644
--- a/nova/exception.py
+++ b/nova/exception.py
@@ -598,3 +598,11 @@ class MigrationError(NovaException):
 
 class MalformedRequestBody(NovaException):
     message = _("Malformed message body: %(reason)s")
+
+
+class PasteConfigNotFound(NotFound):
+    message = _("Could not find paste config at %(path)s")
+
+
+class PasteAppNotFound(NotFound):
+    message = _("Could not load paste app '%(name)s' from %(path)s")
diff --git a/nova/log.py b/nova/log.py
index 6909916a1..f8c0ba68d 100644
--- a/nova/log.py
+++ b/nova/log.py
@@ -314,3 +314,14 @@ logging.setLoggerClass(NovaLogger)
 def audit(msg, *args, **kwargs):
     """Shortcut for logging to root log with sevrity 'AUDIT'."""
     logging.root.log(AUDIT, msg, *args, **kwargs)
+
+
+class WritableLogger(object):
+    """A thin wrapper that responds to `write` and logs."""
+
+    def __init__(self, logger, level=logging.INFO):
+        self.logger = logger
+        self.level = level
+
+    def write(self, msg):
+        self.logger.log(self.level, msg)
diff --git a/nova/service.py b/nova/service.py
index 74f9f04d8..00e4f61e5 100644
--- a/nova/service.py
+++ b/nova/service.py
@@ -19,10 +19,12 @@
 
 """Generic Node baseclass for all workers that run on hosts."""
 
-import greenlet
 import inspect
+import multiprocessing
 import os
 
+import greenlet
+
 from eventlet import greenthread
 
 from nova import context
@@ -36,6 +38,8 @@ from nova import version
 from nova import wsgi
 
 
+LOG = logging.getLogger('nova.service')
+
 FLAGS = flags.FLAGS
 flags.DEFINE_integer('report_interval', 10,
                      'seconds between nodes reporting state to datastore',
@@ -53,6 +57,63 @@ flags.DEFINE_string('api_paste_config', "api-paste.ini",
                     'File name for the paste.deploy config for nova-api')
 
 
+class Launcher(object):
+    """Launch one or more services and wait for them to complete."""
+
+    def __init__(self):
+        """Initialize the service launcher.
+
+        :returns: None
+
+        """
+        self._services = []
+
+    @staticmethod
+    def run_service(service):
+        """Start and wait for a service to finish.
+
+        :param service: Service to run and wait for.
+        :returns: None
+
+        """
+        service.start()
+        try:
+            service.wait()
+        except KeyboardInterrupt:
+            service.stop()
+
+    def launch_service(self, service):
+        """Load and start the given service.
+
+        :param service: The service you would like to start.
+        :returns: None
+
+        """
+        process = multiprocessing.Process(target=self.run_service,
+                                          args=(service,))
+        process.start()
+        self._services.append(process)
+
+    def stop(self):
+        """Stop all services which are currently running.
+
+        :returns: None
+
+        """
+        for service in self._services:
+            if service.is_alive():
+                service.terminate()
+
+    def wait(self):
+        """Waits until all services have been stopped, and then returns.
+
+        :returns: None
+
+        """
+        for service in self._services:
+            service.join()
+
+
 class Service(object):
     """Base class for workers that run on hosts."""
 
@@ -232,45 +293,54 @@ class Service(object):
                 logging.exception(_('model server went away'))
 
 
-class WsgiService(object):
-    """Base class for WSGI based services.
+class WSGIService(object):
+    """Provides ability to launch API from a 'paste' configuration."""
 
-    For each api you define, you must also define these flags:
-    :<api>_listen: The address on which to listen
-    :<api>_listen_port: The port on which to listen
+    def __init__(self, name, loader=None):
+        """Initialize, but do not start the WSGI service.
 
-    """
+        :param name: The name of the WSGI service given to the loader.
+        :param loader: Loads the WSGI application using the given name.
+        :returns: None
 
-    def __init__(self, conf, apis):
-        self.conf = conf
-        self.apis = apis
-        self.wsgi_app = None
+        """
+        self.name = name
+        self.loader = loader or wsgi.Loader()
+        self.app = self.loader.load_app(name)
+        self.host = getattr(FLAGS, '%s_listen' % name, "0.0.0.0")
+        self.port = getattr(FLAGS, '%s_listen_port' % name, 0)
+        self.server = wsgi.Server(name,
+                                  self.app,
+                                  host=self.host,
+                                  port=self.port)
 
     def start(self):
-        self.wsgi_app = _run_wsgi(self.conf, self.apis)
+        """Start serving this service using loaded configuration.
 
-    def wait(self):
-        self.wsgi_app.wait()
+        Also, retrieve updated port number in case '0' was passed in, which
+        indicates a random port should be used.
 
-    def get_socket_info(self, api_name):
-        """Returns the (host, port) that an API was started on."""
-        return self.wsgi_app.socket_info[api_name]
+        :returns: None
 
+        """
+        self.server.start()
+        self.port = self.server.port
 
-class ApiService(WsgiService):
-    """Class for our nova-api service."""
+    def stop(self):
+        """Stop serving this API.
 
-    @classmethod
-    def create(cls, conf=None):
-        if not conf:
-            conf = wsgi.paste_config_file(FLAGS.api_paste_config)
-            if not conf:
-                message = (_('No paste configuration found for: %s'),
-                           FLAGS.api_paste_config)
-                raise exception.Error(message)
-        api_endpoints = ['ec2', 'osapi']
-        service = cls(conf, api_endpoints)
-        return service
+        :returns: None
+
+        """
+        self.server.stop()
+
+    def wait(self):
+        """Wait for the service to stop serving this API.
+
+        :returns: None
+
+        """
+        self.server.wait()
 
 
 def serve(*services):
@@ -302,48 +372,3 @@ def serve(*services):
 def wait():
     while True:
         greenthread.sleep(5)
-
-
-def serve_wsgi(cls, conf=None):
-    try:
-        service = cls.create(conf)
-    except Exception:
-        logging.exception('in WsgiService.create()')
-        raise
-    finally:
-        # After we've loaded up all our dynamic bits, check
-        # whether we should print help
-        flags.DEFINE_flag(flags.HelpFlag())
-        flags.DEFINE_flag(flags.HelpshortFlag())
-        flags.DEFINE_flag(flags.HelpXMLFlag())
-        FLAGS.ParseNewFlags()
-
-    service.start()
-
-    return service
-
-
-def _run_wsgi(paste_config_file, apis):
-    logging.debug(_('Using paste.deploy config at: %s'), paste_config_file)
-    apps = []
-    for api in apis:
-        config = wsgi.load_paste_configuration(paste_config_file, api)
-        if config is None:
-            logging.debug(_('No paste configuration for app: %s'), api)
-            continue
-        logging.debug(_('App Config: %(api)s\n%(config)r') % locals())
-        logging.info(_('Running %s API'), api)
-        app = wsgi.load_paste_app(paste_config_file, api)
-        apps.append((app,
-                     getattr(FLAGS, '%s_listen_port' % api),
-                     getattr(FLAGS, '%s_listen' % api),
-                     api))
-    if len(apps) == 0:
-        logging.error(_('No known API applications configured in %s.'),
-                      paste_config_file)
-        return
-
-    server = wsgi.Server()
-    for app in apps:
-        server.start(*app)
-    return server
diff --git a/nova/test.py b/nova/test.py
index 4a0a18fe7..ab1eaf5fd 100644
--- a/nova/test.py
+++ b/nova/test.py
@@ -38,7 +38,6 @@ from nova import flags
 from nova import rpc
 from nova import utils
 from nova import service
-from nova import wsgi
 from nova.virt import fake
 
 
@@ -81,7 +80,6 @@ class TestCase(unittest.TestCase):
         self.injected = []
         self._services = []
         self._monkey_patch_attach()
-        self._monkey_patch_wsgi()
         self._original_flags = FLAGS.FlagValuesDict()
         rpc.ConnectionPool = rpc.Pool(max_size=FLAGS.rpc_conn_pool_size)
 
@@ -107,7 +105,6 @@ class TestCase(unittest.TestCase):
 
             # Reset our monkey-patches
             rpc.Consumer.attach_to_eventlet = self.original_attach
-            wsgi.Server.start = self.original_start
 
             # Stop any timers
             for x in self.injected:
@@ -163,26 +160,6 @@ class TestCase(unittest.TestCase):
         _wrapped.func_name = self.original_attach.func_name
         rpc.Consumer.attach_to_eventlet = _wrapped
 
-    def _monkey_patch_wsgi(self):
-        """Allow us to kill servers spawned by wsgi.Server."""
-        self.original_start = wsgi.Server.start
-
-        @functools.wraps(self.original_start)
-        def _wrapped_start(inner_self, *args, **kwargs):
-            original_spawn_n = inner_self.pool.spawn_n
-
-            @functools.wraps(original_spawn_n)
-            def _wrapped_spawn_n(*args, **kwargs):
-                rv = greenthread.spawn(*args, **kwargs)
-                self._services.append(rv)
-
-            inner_self.pool.spawn_n = _wrapped_spawn_n
-            self.original_start(inner_self, *args, **kwargs)
-            inner_self.pool.spawn_n = original_spawn_n
-
-        _wrapped_start.func_name = self.original_start.func_name
-        wsgi.Server.start = _wrapped_start
-
     # Useful assertions
     def assertDictMatch(self, d1, d2, approx_equal=False, tolerance=0.001):
         """Assert two dicts are equivalent.
diff --git a/nova/tests/integrated/integrated_helpers.py b/nova/tests/integrated/integrated_helpers.py
index 522c7cb0e..47bd8c1e4 100644
--- a/nova/tests/integrated/integrated_helpers.py
+++ b/nova/tests/integrated/integrated_helpers.py
@@ -171,16 +171,10 @@ class _IntegratedTestBase(test.TestCase):
         self.api = self.user.openstack_api
 
     def _start_api_service(self):
-        api_service = service.ApiService.create()
-        api_service.start()
-
-        if not api_service:
-            raise Exception("API Service was None")
-
-        self.api_service = api_service
-
-        host, port = api_service.get_socket_info('osapi')
-        self.auth_url = 'http://%s:%s/v1.1' % (host, port)
+        osapi = service.WSGIService("osapi")
+        osapi.start()
+        self.auth_url = 'http://%s:%s/v1.1' % (osapi.host, osapi.port)
+        LOG.warn(self.auth_url)
 
     def tearDown(self):
         self.context.cleanup()
diff --git a/nova/tests/test_objectstore.py b/nova/tests/test_objectstore.py
index c78772f27..39b4e18d7 100644
--- a/nova/tests/test_objectstore.py
+++ b/nova/tests/test_objectstore.py
@@ -70,11 +70,15 @@ class S3APITestCase(test.TestCase):
         os.mkdir(FLAGS.buckets_path)
 
         router = s3server.S3Application(FLAGS.buckets_path)
-        server = wsgi.Server()
-        server.start(router, FLAGS.s3_port, host=FLAGS.s3_host)
+        self.server = wsgi.Server("S3 Objectstore",
+                                  router,
+                                  host=FLAGS.s3_host,
+                                  port=FLAGS.s3_port)
+        self.server.start()
 
         if not boto.config.has_section('Boto'):
             boto.config.add_section('Boto')
+
         boto.config.set('Boto', 'num_retries', '0')
         conn = s3.S3Connection(aws_access_key_id=self.admin_user.access,
                                aws_secret_access_key=self.admin_user.secret,
@@ -145,4 +149,5 @@ class S3APITestCase(test.TestCase):
         """Tear down auth and test server."""
         self.auth_manager.delete_user('admin')
         self.auth_manager.delete_project('admin')
+        self.server.stop()
         super(S3APITestCase, self).tearDown()
diff --git a/nova/tests/test_service.py b/nova/tests/test_service.py
index d1cc8bd61..f45f76b73 100644
--- a/nova/tests/test_service.py
+++ b/nova/tests/test_service.py
@@ -30,6 +30,7 @@ from nova import rpc
 from nova import test
 from nova import service
 from nova import manager
+from nova import wsgi
 from nova.compute import manager as compute_manager
 
 FLAGS = flags.FLAGS
@@ -349,3 +350,32 @@ class ServiceTestCase(test.TestCase):
         serv.stop()
 
         db.service_destroy(ctxt, service_ref['id'])
+
+
+class TestWSGIService(test.TestCase):
+
+    def setUp(self):
+        super(TestWSGIService, self).setUp()
+        self.stubs.Set(wsgi.Loader, "load_app", mox.MockAnything())
+
+    def test_service_random_port(self):
+        test_service = service.WSGIService("test_service")
+        self.assertEquals(0, test_service.port)
+        test_service.start()
+        self.assertNotEqual(0, test_service.port)
+        test_service.stop()
+
+
+class TestLauncher(test.TestCase):
+
+    def setUp(self):
+        super(TestLauncher, self).setUp()
+        self.stubs.Set(wsgi.Loader, "load_app", mox.MockAnything())
+        self.service = service.WSGIService("test_service")
+
+    def test_launch_app(self):
+        self.assertEquals(0, self.service.port)
+        launcher = service.Launcher()
+        launcher.launch_service(self.service)
+        self.assertEquals(0, self.service.port)
+        launcher.stop()
diff --git a/nova/tests/test_wsgi.py b/nova/tests/test_wsgi.py
new file mode 100644
index 000000000..b71e8d418
--- /dev/null
+++ b/nova/tests/test_wsgi.py
@@ -0,0 +1,95 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2011 United States Government as represented by the
+# Administrator of the National Aeronautics and Space Administration.
+# 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.
+
+"""Unit tests for `nova.wsgi`."""
+
+import os.path
+import tempfile
+
+import unittest
+
+import nova.exception
+import nova.test
+import nova.wsgi
+
+
+class TestLoaderNothingExists(unittest.TestCase):
+    """Loader tests where os.path.exists always returns False."""
+
+    def setUp(self):
+        self._os_path_exists = os.path.exists
+        os.path.exists = lambda _: False
+
+    def test_config_not_found(self):
+        self.assertRaises(
+            nova.exception.PasteConfigNotFound,
+            nova.wsgi.Loader,
+        )
+
+    def tearDown(self):
+        os.path.exists = self._os_path_exists
+
+
+class TestLoaderNormalFilesystem(unittest.TestCase):
+    """Loader tests with normal filesystem (unmodified os.path module)."""
+
+    _paste_config = """
+[app:test_app]
+use = egg:Paste#static
+document_root = /tmp
+    """
+
+    def setUp(self):
+        self.config = tempfile.NamedTemporaryFile(mode="w+t")
+        self.config.write(self._paste_config.lstrip())
+        self.config.seek(0)
+        self.config.flush()
+        self.loader = nova.wsgi.Loader(self.config.name)
+
+    def test_config_found(self):
+        self.assertEquals(self.config.name, self.loader.config_path)
+
+    def test_app_not_found(self):
+        self.assertRaises(
+            nova.exception.PasteAppNotFound,
+            self.loader.load_app,
+            "non-existant app",
+        )
+
+    def test_app_found(self):
+        url_parser = self.loader.load_app("test_app")
+        self.assertEquals("/tmp", url_parser.directory)
+
+    def tearDown(self):
+        self.config.close()
+
+
+class TestWSGIServer(unittest.TestCase):
+    """WSGI server tests."""
+
+    def test_no_app(self):
+        server = nova.wsgi.Server("test_app", None)
+        self.assertEquals("test_app", server.name)
+
+    def test_start_random_port(self):
+        server = nova.wsgi.Server("test_random_port", None, host="127.0.0.1")
+        self.assertEqual(0, server.port)
+        server.start()
+        self.assertNotEqual(0, server.port)
+        server.stop()
+        server.wait()
diff --git a/nova/utils.py b/nova/utils.py
index 6d8324e5b..918541224 100644
--- a/nova/utils.py
+++ b/nova/utils.py
@@ -46,6 +46,7 @@ from eventlet.green import subprocess
 from nova import exception
 from nova import flags
 from nova import log as logging
+from nova import version
 
 
 LOG = logging.getLogger("nova.utils")
@@ -226,8 +227,10 @@ def novadir():
     return os.path.abspath(nova.__file__).split('nova/__init__.pyc')[0]
 
 
-def default_flagfile(filename='nova.conf'):
-    for arg in sys.argv:
+def default_flagfile(filename='nova.conf', args=None):
+    if args is None:
+        args = sys.argv
+    for arg in args:
         if arg.find('flagfile') != -1:
             break
     else:
@@ -239,8 +242,8 @@ def default_flagfile(filename='nova.conf'):
             filename = "./nova.conf"
             if not os.path.exists(filename):
                 filename = '/etc/nova/nova.conf'
-        flagfile = ['--flagfile=%s' % filename]
-        sys.argv = sys.argv[:1] + flagfile + sys.argv[1:]
+        flagfile = '--flagfile=%s' % filename
+        args.insert(1, flagfile)
 
 
 def debug(arg):
@@ -751,3 +754,39 @@ def is_uuid_like(val):
     if not isinstance(val, basestring):
         return False
     return (len(val) == 36) and (val.count('-') == 4)
+
+
+class Bootstrapper(object):
+    """Provides environment bootstrapping capabilities for entry points."""
+
+    @staticmethod
+    def bootstrap_binary(argv):
+        """Initialize the Nova environment using command line arguments."""
+        Bootstrapper.setup_flags(argv)
+        Bootstrapper.setup_logging()
+        Bootstrapper.log_flags()
+
+    @staticmethod
+    def setup_logging():
+        """Initialize logging and log a message indicating the Nova version."""
+        logging.setup()
+        logging.audit(_("Nova Version (%s)") %
+                        version.version_string_with_vcs())
+
+    @staticmethod
+    def setup_flags(input_flags):
+        """Initialize flags, load flag file, and print help if needed."""
+        default_flagfile(args=input_flags)
+        FLAGS(input_flags or [])
+        flags.DEFINE_flag(flags.HelpFlag())
+        flags.DEFINE_flag(flags.HelpshortFlag())
+        flags.DEFINE_flag(flags.HelpXMLFlag())
+        FLAGS.ParseNewFlags()
+
+    @staticmethod
+    def log_flags():
+        """Log the list of all active flags being used."""
+        logging.audit(_("Currently active flags:"))
+        for key in FLAGS:
+            value = FLAGS.get(key, None)
+            logging.audit(_("%(key)s : %(value)s" % locals()))
diff --git a/nova/wsgi.py b/nova/wsgi.py
index 33ba852bc..23d29079f 100644
--- a/nova/wsgi.py
+++ b/nova/wsgi.py
@@ -21,16 +21,16 @@
 
 import os
 import sys
+
 from xml.dom import minidom
 
 import eventlet
 import eventlet.wsgi
-eventlet.patcher.monkey_patch(all=False, socket=True, time=True)
-import routes
+import greenlet
 import routes.middleware
-import webob
 import webob.dec
 import webob.exc
+
 from paste import deploy
 
 from nova import exception
@@ -39,49 +39,86 @@ from nova import log as logging
 from nova import utils
 
 
+eventlet.patcher.monkey_patch(socket=True, time=True)
+
+
 FLAGS = flags.FLAGS
 LOG = logging.getLogger('nova.wsgi')
 
 
-class WritableLogger(object):
-    """A thin wrapper that responds to `write` and logs."""
+class Server(object):
+    """Server class to manage a WSGI server, serving a WSGI application."""
 
-    def __init__(self, logger, level=logging.DEBUG):
-        self.logger = logger
-        self.level = level
+    default_pool_size = 1000
 
-    def write(self, msg):
-        self.logger.log(self.level, msg)
+    def __init__(self, name, app, host=None, port=None, pool_size=None):
+        """Initialize, but do not start, a WSGI server.
 
+        :param name: Pretty name for logging.
+        :param app: The WSGI application to serve.
+        :param host: IP address to serve the application.
+        :param port: Port number to server the application.
+        :param pool_size: Maximum number of eventlets to spawn concurrently.
+        :returns: None
 
-class Server(object):
-    """Server class to manage multiple WSGI sockets and applications."""
+        """
+        self.name = name
+        self.app = app
+        self.host = host or "0.0.0.0"
+        self.port = port or 0
+        self._server = None
+        self._socket = None
+        self._pool = eventlet.GreenPool(pool_size or self.default_pool_size)
+        self._logger = logging.getLogger("eventlet.wsgi.server")
+        self._wsgi_logger = logging.WritableLogger(self._logger)
+
+    def _start(self):
+        """Run the blocking eventlet WSGI server.
+
+        :returns: None
+
+        """
+        eventlet.wsgi.server(self._socket,
+                             self.app,
+                             custom_pool=self._pool,
+                             log=self._wsgi_logger)
+
+    def start(self, backlog=128):
+        """Start serving a WSGI application.
+
+        :param backlog: Maximum number of queued connections.
+        :returns: None
+
+        """
+        self._socket = eventlet.listen((self.host, self.port), backlog=backlog)
+        self._server = eventlet.spawn(self._start)
+        (self.host, self.port) = self._socket.getsockname()
+        LOG.info(_("Started %(name)s on %(host)s:%(port)s") % self.__dict__)
+
+    def stop(self):
+        """Stop this server.
+
+        This is not a very nice action, as currently the method by which a
+        server is stopped is by killing it's eventlet.
 
-    def __init__(self, threads=1000):
-        self.pool = eventlet.GreenPool(threads)
-        self.socket_info = {}
+        :returns: None
 
-    def start(self, application, port, host='0.0.0.0', key=None, backlog=128):
-        """Run a WSGI server with the given application."""
-        arg0 = sys.argv[0]
-        logging.audit(_('Starting %(arg0)s on %(host)s:%(port)s') % locals())
-        socket = eventlet.listen((host, port), backlog=backlog)
-        self.pool.spawn_n(self._run, application, socket)
-        if key:
-            self.socket_info[key] = socket.getsockname()
+        """
+        LOG.info(_("Stopping WSGI server."))
+        self._server.kill()
 
     def wait(self):
-        """Wait until all servers have completed running."""
-        try:
-            self.pool.waitall()
-        except KeyboardInterrupt:
-            pass
+        """Block, until the server has stopped.
+
+        Waits on the server's eventlet to finish, then returns.
 
-    def _run(self, application, socket):
-        """Start a WSGI server in a new green thread."""
-        logger = logging.getLogger('eventlet.wsgi.server')
-        eventlet.wsgi.server(socket, application, custom_pool=self.pool,
-                             log=WritableLogger(logger))
+        :returns: None
+
+        """
+        try:
+            self._server.wait()
+        except greenlet.GreenletExit:
+            LOG.info(_("WSGI server has stopped."))
 
 
 class Request(webob.Request):
@@ -309,55 +346,51 @@ class Router(object):
         return app
 
 
-def paste_config_file(basename):
-    """Find the best location in the system for a paste config file.
+class Loader(object):
+    """Used to load WSGI applications from paste configurations."""
+
+    def __init__(self, config_path=None):
+        """Initialize the loader, and attempt to find the config.
 
-    Search Order
-    ------------
+        :param config_path: Full or relative path to the paste config.
+        :returns: None
 
-    The search for a paste config file honors `FLAGS.state_path`, which in a
-    version checked out from bzr will be the `nova` directory in the top level
-    of the checkout, and in an installation for a package for your distribution
-    will likely point to someplace like /etc/nova.
+        """
+        config_path = config_path or FLAGS.api_paste_config
+        self.config_path = self._find_config(config_path)
 
-    This method tries to load places likely to be used in development or
-    experimentation before falling back to the system-wide configuration
-    in `/etc/nova/`.
+    def _find_config(self, config_path):
+        """Find the paste configuration file using the given hint.
 
-    * Current working directory
-    * the `etc` directory under state_path, because when working on a checkout
-      from bzr this will point to the default
-    * top level of FLAGS.state_path, for distributions
-    * /etc/nova, which may not be diffrerent from state_path on your distro
+        :param config_path: Full or relative path to the paste config.
+        :returns: Full path of the paste config, if it exists.
+        :raises: `nova.exception.PasteConfigNotFound`
 
-    """
-    configfiles = [basename,
-                   os.path.join(FLAGS.state_path, 'etc', 'nova', basename),
-                   os.path.join(FLAGS.state_path, 'etc', basename),
-                   os.path.join(FLAGS.state_path, basename),
-                   '/etc/nova/%s' % basename]
-    for configfile in configfiles:
-        if os.path.exists(configfile):
-            return configfile
-
-
-def load_paste_configuration(filename, appname):
-    """Returns a paste configuration dict, or None."""
-    filename = os.path.abspath(filename)
-    config = None
-    try:
-        config = deploy.appconfig('config:%s' % filename, name=appname)
-    except LookupError:
-        pass
-    return config
-
-
-def load_paste_app(filename, appname):
-    """Builds a wsgi app from a paste config, None if app not configured."""
-    filename = os.path.abspath(filename)
-    app = None
-    try:
-        app = deploy.loadapp('config:%s' % filename, name=appname)
-    except LookupError:
-        pass
-    return app
+        """
+        possible_locations = [
+            config_path,
+            os.path.join(FLAGS.state_path, "etc", "nova", config_path),
+            os.path.join(FLAGS.state_path, "etc", config_path),
+            os.path.join(FLAGS.state_path, config_path),
+            "/etc/nova/%s" % config_path,
+        ]
+
+        for path in possible_locations:
+            if os.path.exists(path):
+                return os.path.abspath(path)
+
+        raise exception.PasteConfigNotFound(path=os.path.abspath(config_path))
+
+    def load_app(self, name):
+        """Return the paste URLMap wrapped WSGI application.
+
+        :param name: Name of the application to load.
+        :returns: Paste URLMap object wrapping the requested application.
+        :raises: `nova.exception.PasteAppNotFound`
+
+        """
+        try:
+            return deploy.loadapp("config:%s" % self.config_path, name=name)
+        except LookupError as err:
+            LOG.error(err)
+            raise exception.PasteAppNotFound(name=name, path=self.config_path)
diff --git a/tools/pip-requires b/tools/pip-requires
index 99d737e9f..6e686b7e7 100644
--- a/tools/pip-requires
+++ b/tools/pip-requires
@@ -7,7 +7,7 @@ amqplib==0.6.1
 anyjson==0.2.4
 boto==1.9b
 carrot==0.10.5
-eventlet==0.9.12
+eventlet
 lockfile==0.8
 python-novaclient==2.5.3
 python-daemon==1.5.5