Make sure use IPv6 sockets for ceilometer in IPv6 environment

In IPv6 management network environment, ceilometer command will
throw 'Address family for hostname not support' when use WSGI
simple server. The root cause is python TCPServer implementation
is hard-coded to use IPv4, even in IPv6 environments. Python
community want to fix it in Python3.5, so we need to make a
workaround for it.

Change-Id: I3260a346a095b0f3e57093c18b1920dffe5ac55d
Closes-Bug: #1269243

ceilometer/api/app.py

@@ -18,8 +18,10 @@
 
 import logging
 import os
+import socket
 from wsgiref import simple_server
 
+import netaddr
 from oslo.config import cfg
 import pecan
 
@@ -106,6 +108,20 @@ class VersionSelectorApplication(object):
         return self.v2(environ, start_response)
 
 
+def get_server_cls(host):
+    """Return an appropriate WSGI server class base on provided host
+
+    :param host: The listen host for the ceilometer API server.
+    """
+    server_cls = simple_server.WSGIServer
+    if netaddr.valid_ipv6(host):
+        # NOTE(dzyu) make sure use IPv6 sockets if host is in IPv6 pattern
+        if getattr(server_cls, 'address_family') == socket.AF_INET:
+            class server_cls(server_cls):
+                address_family = socket.AF_INET6
+    return server_cls
+
+
 def start():
     service.prepare_service()
 
@@ -114,7 +130,8 @@ def start():
 
     # Create the WSGI server and start it
     host, port = cfg.CONF.api.host, cfg.CONF.api.port
-    srv = simple_server.make_server(host, port, root)
+    server_cls = get_server_cls(host)
+    srv = simple_server.make_server(host, port, root, server_cls)
 
     LOG.info(_('Starting server in PID %s') % os.getpid())
     LOG.info(_("Configuration:"))

ceilometer/tests/api/test_app.py

@@ -0,0 +1,44 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2014 IBM Corp.
+# 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.
+
+import socket
+
+from oslo.config import cfg
+
+from ceilometer.api import app
+from ceilometer.openstack.common.fixture import config
+from ceilometer.tests import base
+
+
+class TestApp(base.BaseTestCase):
+
+    def setUp(self):
+        super(TestApp, self).setUp()
+        self.CONF = self.useFixture(config.Config()).conf
+
+    def test_WSGI_address_family(self):
+        self.CONF.set_override('host', '::', group='api')
+        server_cls = app.get_server_cls(cfg.CONF.api.host)
+        self.assertEqual(server_cls.address_family, socket.AF_INET6)
+
+        self.CONF.set_override('host', '127.0.0.1', group='api')
+        server_cls = app.get_server_cls(cfg.CONF.api.host)
+        self.assertEqual(server_cls.address_family, socket.AF_INET)
+
+        self.CONF.set_override('host', 'ddddd', group='api')
+        server_cls = app.get_server_cls(cfg.CONF.api.host)
+        self.assertEqual(server_cls.address_family, socket.AF_INET)

requirements.txt

@@ -12,6 +12,7 @@ kombu>=2.4.8
 lockfile>=0.8
 lxml>=2.3
 msgpack-python
+netaddr>=0.7.6
 oslo.config>=1.2.0
 oslo.vmware
 pbr>=0.6,<1.0