Add REST API to show availability_zone of instance.

Implement one workitem for bp:show-availability-zone

This show the availability zone and availability zone of its host in
API: GET /servers/details, GET /server/{uuid}.

When create instance if "availability_zone" doesn't specified, the
"availability_zone" of the instance will be None.  But actually the instance
is in a zone which its host is in. So I think show both of them will be fine.

Change-Id: I2d742ee2d291b514bf783fa79293785cca8ea2a5

1 files changed, 106 insertions, 0 deletions

diff --git a/nova/api/openstack/compute/contrib/extended_availability_zone.py b/nova/api/openstack/compute/contrib/extended_availability_zone.py
new file mode 100644
index 000000000..b7451cb6a
--- /dev/null
+++ b/nova/api/openstack/compute/contrib/extended_availability_zone.py
@@ -0,0 +1,106 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2013 Netease, LLC.
+# 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.
+
+"""The Extended Availability Zone Status API extension."""
+
+from nova.api.openstack import extensions
+from nova.api.openstack import wsgi
+from nova.api.openstack import xmlutil
+from nova import availability_zones
+from nova.openstack.common import log as logging
+
+LOG = logging.getLogger(__name__)
+authorize = extensions.soft_extension_authorizer('compute',
+                                                 'extended_availability_zone')
+
+
+class ExtendedAZController(wsgi.Controller):
+
+    def _get_host_az(self, context, instance):
+        admin_context = context.elevated()
+        if instance['host']:
+            return availability_zones.get_host_availability_zone(
+                                            admin_context, instance['host'])
+
+    def _extend_server(self, context, server, instance):
+        key = "%s:availability_zone" % Extended_availability_zone.alias
+        server[key] = instance.get('availability_zone', None)
+
+        key = "%s:host_availability_zone" % Extended_availability_zone.alias
+        server[key] = self._get_host_az(context, instance)
+
+    @wsgi.extends
+    def show(self, req, resp_obj, id):
+        context = req.environ['nova.context']
+        if authorize(context):
+            resp_obj.attach(xml=ExtendedAZTemplate())
+            server = resp_obj.obj['server']
+            db_instance = req.get_db_instance(server['id'])
+            self._extend_server(context, server, db_instance)
+
+    @wsgi.extends
+    def detail(self, req, resp_obj):
+        context = req.environ['nova.context']
+        if authorize(context):
+            resp_obj.attach(xml=ExtendedAZsTemplate())
+            servers = list(resp_obj.obj['servers'])
+            for server in servers:
+                db_instance = req.get_db_instance(server['id'])
+                self._extend_server(context, server, db_instance)
+
+
+class Extended_availability_zone(extensions.ExtensionDescriptor):
+    """Extended Server Attributes support."""
+
+    name = "ExtendedAvailabilityZone"
+    alias = "OS-EXT-AZ"
+    namespace = ("http://docs.openstack.org/compute/ext/"
+                 "extended_availability_zone/api/v2")
+    updated = "2013-01-30T00:00:00+00:00"
+
+    def get_controller_extensions(self):
+        controller = ExtendedAZController()
+        extension = extensions.ControllerExtension(self, 'servers', controller)
+        return [extension]
+
+
+def make_server(elem):
+    elem.set('{%s}availability_zone' % Extended_availability_zone.namespace,
+             '%s:availability_zone' % Extended_availability_zone.alias)
+    elem.set('{%s}host_availability_zone' %
+             Extended_availability_zone.namespace,
+             '%s:host_availability_zone' %
+             Extended_availability_zone.alias)
+
+
+class ExtendedAZTemplate(xmlutil.TemplateBuilder):
+    def construct(self):
+        root = xmlutil.TemplateElement('server', selector='server')
+        make_server(root)
+        alias = Extended_availability_zone.alias
+        namespace = Extended_availability_zone.namespace
+        return xmlutil.SlaveTemplate(root, 1, nsmap={alias: namespace})
+
+
+class ExtendedAZsTemplate(xmlutil.TemplateBuilder):
+    def construct(self):
+        root = xmlutil.TemplateElement('servers')
+        elem = xmlutil.SubTemplateElement(root, 'server', selector='servers')
+        make_server(elem)
+        alias = Extended_availability_zone.alias
+        namespace = Extended_availability_zone.namespace
+        return xmlutil.SlaveTemplate(root, 1, nsmap={alias: namespace})