Fix HostDeserializer to enable multiple line xml

Fixes bug: 1082132

The current HostDeserializer wasn't able to deal with multiple line xml inputs.
Since the HostDeserializer is used only on the update operation this patch
renames it to HostUpdateDeserializer, and parses only the valid options (status
and maintenance_mode).

Change-Id: I9ec3b296a07e0fc903da1c005cf7bd5dcb08fd1b

nova/api/openstack/compute/contrib/hosts.py

@@ -70,7 +70,7 @@ def construct(self):
         return xmlutil.MasterTemplate(root, 1)
 
 
-class HostDeserializer(wsgi.XMLDeserializer):
+class HostUpdateDeserializer(wsgi.XMLDeserializer):
     def default(self, string):
         try:
             node = minidom.parseString(string)
@@ -79,8 +79,16 @@ def default(self, string):
             raise exception.MalformedRequestBody(reason=msg)
 
         updates = {}
-        for child in node.childNodes[0].childNodes:
-            updates[child.tagName] = self.extract_text(child)
+        updates_node = self.find_first_child_named(node, 'updates')
+        if updates_node is not None:
+            maintenance = self.find_first_child_named(updates_node,
+                                                      'maintenance_mode')
+            if maintenance is not None:
+                updates[maintenance.tagName] = self.extract_text(maintenance)
+
+            status = self.find_first_child_named(updates_node, 'status')
+            if status is not None:
+                updates[status.tagName] = self.extract_text(status)
 
         return dict(body=updates)
 
@@ -131,7 +139,7 @@ def index(self, req):
         return {'hosts': _list_hosts(req)}
 
     @wsgi.serializers(xml=HostUpdateTemplate)
-    @wsgi.deserializers(xml=HostDeserializer)
+    @wsgi.deserializers(xml=HostUpdateDeserializer)
     @check_host
     def update(self, req, id, body):
         authorize(req.environ['nova.context'])

nova/tests/api/openstack/compute/contrib/test_hosts.py

@@ -272,7 +272,7 @@ def test_show_works_correctly(self):
 class HostSerializerTest(test.TestCase):
     def setUp(self):
         super(HostSerializerTest, self).setUp()
-        self.deserializer = os_hosts.HostDeserializer()
+        self.deserializer = os_hosts.HostUpdateDeserializer()
 
     def test_index_serializer(self):
         serializer = os_hosts.HostIndexTemplate()
@@ -336,9 +336,12 @@ def test_action_serializer(self):
             self.assertEqual(value, tree.get(key))
 
     def test_update_deserializer(self):
-        exemplar = dict(status='enabled', foo='bar')
-        intext = ("<?xml version='1.0' encoding='UTF-8'?>\n"
-                  '<updates><status>enabled</status><foo>bar</foo></updates>')
+        exemplar = dict(status='enabled', maintenance_mode='disable')
+        intext = """<?xml version='1.0' encoding='UTF-8'?>
+    <updates>
+        <status>enabled</status>
+        <maintenance_mode>disable</maintenance_mode>
+    </updates>"""
         result = self.deserializer.deserialize(intext)
 
         self.assertEqual(dict(body=exemplar), result)