Verify create agent attributes of V2/V3 APIs

This patch adds the JSON schema for Nova V2/V3 create agent APIs
includes the attributes to block the backward incompatibility change
in the future.

The response body of v2 and v3 API is the below:
{
    "agent": {
        "agent_id": 1,
        "hypervisor": "xen",
        "os": "linux",
        "architecture": "x86",
        "version": "7.0",
        "url": "xxx://xxx/xxx/xxx1",
        "md5hash": "add6bb58e139be103324d04d82d8f546"
    }
}

Partially implements blueprint nova-api-attribute-test

Change-Id: I86aeae6a6337ce60e2b69e207a6e015950b95a36

tempest/api_schema/compute/agents.py

@@ -38,3 +38,24 @@ list_agents = {
         'required': ['agents']
     }
 }
+
+common_create_agent = {
+    'type': 'object',
+    'properties': {
+        'agent': {
+            'type': 'object',
+            'properties': {
+                'agent_id': {'type': ['integer', 'string']},
+                'hypervisor': {'type': 'string'},
+                'os': {'type': 'string'},
+                'architecture': {'type': 'string'},
+                'version': {'type': 'string'},
+                'url': {'type': 'string', 'format': 'uri'},
+                'md5hash': {'type': 'string'}
+            },
+            'required': ['agent_id', 'hypervisor', 'os', 'architecture',
+                         'version', 'url', 'md5hash']
+        }
+    },
+    'required': ['agent']
+}

tempest/api_schema/compute/v2/agents.py

@@ -12,6 +12,13 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from tempest.api_schema.compute import agents
+
+create_agent = {
+    'status_code': [200],
+    'response_body': agents.common_create_agent
+}
+
 delete_agent = {
     'status_code': [200]
 }

tempest/api_schema/compute/v3/agents.py

@@ -12,6 +12,13 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from tempest.api_schema.compute import agents
+
+create_agent = {
+    'status_code': [201],
+    'response_body': agents.common_create_agent
+}
+
 delete_agent = {
     'status_code': [204]
 }

tempest/services/compute/json/agents_client.py

@@ -46,7 +46,9 @@ class AgentsClientJSON(rest_client.RestClient):
         """Create an agent build."""
         post_body = json.dumps({'agent': kwargs})
         resp, body = self.post('os-agents', post_body)
-        return resp, self._parse_resp(body)
+        body = json.loads(body)
+        self.validate_response(schema.create_agent, resp, body)
+        return resp, body['agent']
 
     def delete_agent(self, agent_id):
         """Delete an existing agent build."""

tempest/services/compute/v3/json/agents_client.py

@@ -43,7 +43,9 @@ class AgentsV3ClientJSON(rest_client.RestClient):
         """Create an agent build."""
         post_body = json.dumps({'agent': kwargs})
         resp, body = self.post('os-agents', post_body)
-        return resp, self._parse_resp(body)
+        body = json.loads(body)
+        self.validate_response(schema.create_agent, resp, body)
+        return resp, body['agent']
 
     def delete_agent(self, agent_id):
         """Delete an existing agent build."""