Validate of Nova list Floating IPs attributes

This patch adds the JSON schema for Nova list Floating IPs API
response and validate the response of list Floating IPs API
with added JSON schema to block the backward incompatibility
change in the future.

The response body of list Floating IPs API is below:

{
    "floating_ips": [
        {
            "id": 1,
            "pool": "nova",
            "instance_id": null,
            "ip": "10.10.10.1",
            "fixed_ip": null,
        }
    ]
}

Partially implements blueprint nova-api-attribute-test

Change-Id: Ica266688af310bb804bcf7fb240ca6a005b156c0
diff --git a/tempest/api_schema/compute/v2/floating_ips.py b/tempest/api_schema/compute/v2/floating_ips.py
new file mode 100644
index 0000000..61582ec
--- /dev/null
+++ b/tempest/api_schema/compute/v2/floating_ips.py
@@ -0,0 +1,46 @@
+# Copyright 2014 NEC Corporation.  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.
+
+list_floating_ips = {
+    'status_code': [200],
+    'response_body': {
+        'type': 'object',
+        'properties': {
+            'floating_ips': {
+                'type': 'array',
+                'items': {
+                    'type': 'object',
+                    'properties': {
+                        # NOTE: Now the type of 'id' is integer, but
+                        # here allows 'string' also because we will be
+                        # able to change it to 'uuid' in the future.
+                        'id': {'type': ['integer', 'string']},
+                        'pool': {'type': ['string', 'null']},
+                        'instance_id': {'type': ['integer', 'string', 'null']},
+                        'ip': {
+                            'type': 'string',
+                            'format': 'ip-address'
+                        },
+                        'fixed_ip': {
+                            'type': ['string', 'null'],
+                            'format': 'ip-address'
+                        }
+                    },
+                    'required': ['id', 'pool', 'instance_id', 'ip', 'fixed_ip']
+                }
+            }
+        },
+        'required': ['floating_ips']
+    }
+}
diff --git a/tempest/services/compute/json/floating_ips_client.py b/tempest/services/compute/json/floating_ips_client.py
index 42487c3..2a7e25a 100644
--- a/tempest/services/compute/json/floating_ips_client.py
+++ b/tempest/services/compute/json/floating_ips_client.py
@@ -16,6 +16,7 @@
 import json
 import urllib
 
+from tempest.api_schema.compute.v2 import floating_ips as schema
 from tempest.common import rest_client
 from tempest import config
 from tempest import exceptions
@@ -36,6 +37,7 @@
 
         resp, body = self.get(url)
         body = json.loads(body)
+        self.validate_response(schema.list_floating_ips, resp, body)
         return resp, body['floating_ips']
 
     def get_floating_ip_details(self, floating_ip_id):