Validate hypervisors_servers Nova V2/V3 API

This patch adds the JSON Schema for response of Nova V2 & V3
hypervisors_servers  API and validate the response with added
JSON Schema to block the backward incompatibility change in the future.

The response body of V2 hypervisors_servers API is below:

{
    "hypervisors": [
        {
            "id": 1,
            "hypervisor_hostname": "fake-mini",
            "servers": []
        }
    ]
}

The response body of V3 hypervisors_servers API is below:

{
    "hypervisor": {
        "id": 1,
        "hypervisor_hostname": "fake-mini",
        "servers": []
    }
}

Partially implements blueprint nova-api-attribute-test

Change-Id: I0456c9f2cd9576edd8ce457ac805fab3ba03c060
diff --git a/tempest/api_schema/compute/hypervisors.py b/tempest/api_schema/compute/hypervisors.py
index 7de5147..a935f87 100644
--- a/tempest/api_schema/compute/hypervisors.py
+++ b/tempest/api_schema/compute/hypervisors.py
@@ -147,3 +147,42 @@
         'required': ['hypervisor']
     }
 }
+
+common_hypervisors_detail = {
+    'status_code': [200],
+    'response_body': {
+        'type': 'object',
+        'properties': {
+            'hypervisors': {
+                'type': 'array',
+                'items': {
+                    'type': 'object',
+                    'properties': {
+                        'id': {'type': ['integer', 'string']},
+                        'hypervisor_hostname': {'type': 'string'}
+                    },
+                    'required': ['id', 'hypervisor_hostname']
+                }
+            }
+        },
+        'required': ['hypervisors']
+    }
+}
+
+common_hypervisors_info = {
+    'status_code': [200],
+    'response_body': {
+        'type': 'object',
+        'properties': {
+            'hypervisor': {
+                'type': 'object',
+                'properties': {
+                    'id': {'type': ['integer', 'string']},
+                    'hypervisor_hostname': {'type': 'string'},
+                },
+                'required': ['id', 'hypervisor_hostname']
+            }
+        },
+        'required': ['hypervisor']
+    }
+}
diff --git a/tempest/api_schema/compute/v2/hypervisors.py b/tempest/api_schema/compute/v2/hypervisors.py
new file mode 100644
index 0000000..6bb43a7
--- /dev/null
+++ b/tempest/api_schema/compute/v2/hypervisors.py
@@ -0,0 +1,37 @@
+# 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.
+
+import copy
+from tempest.api_schema.compute import hypervisors
+
+hypervisors_servers = copy.deepcopy(hypervisors.common_hypervisors_detail)
+
+# Defining extra attributes for V3 show hypervisor schema
+hypervisors_servers['response_body']['properties']['hypervisors']['items'][
+    'properties']['servers'] = {
+        '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']},
+                'name': {'type': 'string'}
+            }
+        }
+    }
+# In V2 API, if there is no servers (VM) on the Hypervisor host then 'servers'
+# attribute will not be present in response body So it is not 'required'.
diff --git a/tempest/api_schema/compute/v3/hypervisors.py b/tempest/api_schema/compute/v3/hypervisors.py
index 6eb0072..aa31827 100644
--- a/tempest/api_schema/compute/v3/hypervisors.py
+++ b/tempest/api_schema/compute/v3/hypervisors.py
@@ -25,3 +25,26 @@
 # Defining extra attributes for V3 show hypervisor schema
 show_hypervisor['response_body']['properties']['hypervisor']['properties'][
     'os-pci:pci_stats'] = {'type': 'array'}
+
+hypervisors_servers = copy.deepcopy(hypervisors.common_hypervisors_info)
+
+# Defining extra attributes for V3 show hypervisor schema
+hypervisors_servers['response_body']['properties']['hypervisor']['properties'][
+    'servers'] = {
+        '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']},
+                'name': {'type': 'string'}
+            }
+        }
+    }
+# V3 API response body always contains the 'servers' attribute even there
+# is no server (VM) are present on Hypervisor host.
+hypervisors_servers['response_body']['properties']['hypervisor'][
+    'required'] = ['id', 'hypervisor_hostname', 'servers']
diff --git a/tempest/services/compute/json/hypervisor_client.py b/tempest/services/compute/json/hypervisor_client.py
index 89a7961..28ca2a6 100644
--- a/tempest/services/compute/json/hypervisor_client.py
+++ b/tempest/services/compute/json/hypervisor_client.py
@@ -16,6 +16,7 @@
 import json
 
 from tempest.api_schema.compute import hypervisors as common_schema
+from tempest.api_schema.compute.v2 import hypervisors as v2schema
 from tempest.common import rest_client
 from tempest import config
 
@@ -54,6 +55,7 @@
         """List instances belonging to the specified hypervisor."""
         resp, body = self.get('os-hypervisors/%s/servers' % hyper_name)
         body = json.loads(body)
+        self.validate_response(v2schema.hypervisors_servers, resp, body)
         return resp, body['hypervisors']
 
     def get_hypervisor_stats(self):
diff --git a/tempest/services/compute/v3/json/hypervisor_client.py b/tempest/services/compute/v3/json/hypervisor_client.py
index 0ba6ebf..abe6788 100644
--- a/tempest/services/compute/v3/json/hypervisor_client.py
+++ b/tempest/services/compute/v3/json/hypervisor_client.py
@@ -53,6 +53,7 @@
         """List instances belonging to the specified hypervisor."""
         resp, body = self.get('os-hypervisors/%s/servers' % hyper_name)
         body = json.loads(body)
+        self.validate_response(v3schema.hypervisors_servers, resp, body)
         return resp, body['hypervisor']
 
     def get_hypervisor_stats(self):