Adds list pool stat test case

This submission is to validate the list pool stat feature.
Adds a test case to test_loadbalancer.py and support function
in XML/JSON interfaces

Change-Id: Ia284334c9127ec200a48c098d28bdaf188281887
diff --git a/tempest/api/network/test_load_balancer.py b/tempest/api/network/test_load_balancer.py
index d5f2b5b..c7bc210 100644
--- a/tempest/api/network/test_load_balancer.py
+++ b/tempest/api/network/test_load_balancer.py
@@ -209,6 +209,17 @@
                      (self.health_monitor['id'], self.pool['id']))
         self.assertEqual('204', resp['status'])
 
+    @test.attr(type='smoke')
+    def test_get_lb_pool_stats(self):
+        # Verify the details of pool stats
+        resp, body = self.client.list_lb_pool_stats(self.pool['id'])
+        self.assertEqual('200', resp['status'])
+        stats = body['stats']
+        self.assertIn("bytes_in", stats)
+        self.assertIn("total_connections", stats)
+        self.assertIn("active_connections", stats)
+        self.assertIn("bytes_out", stats)
+
 
 class LoadBalancerTestXML(LoadBalancerTestJSON):
     _interface = 'xml'
diff --git a/tempest/services/network/json/network_client.py b/tempest/services/network/json/network_client.py
index 1458c7b..bd06de8 100644
--- a/tempest/services/network/json/network_client.py
+++ b/tempest/services/network/json/network_client.py
@@ -417,3 +417,9 @@
         resp, body = self.put(uri, body)
         body = json.loads(body)
         return resp, body
+
+    def list_lb_pool_stats(self, pool_id):
+        uri = '%s/lb/pools/%s/stats' % (self.uri_prefix, pool_id)
+        resp, body = self.get(uri)
+        body = json.loads(body)
+        return resp, body
diff --git a/tempest/services/network/xml/network_client.py b/tempest/services/network/xml/network_client.py
index 720c842..5404f1e 100644
--- a/tempest/services/network/xml/network_client.py
+++ b/tempest/services/network/xml/network_client.py
@@ -321,6 +321,12 @@
         resp, body = self.delete(uri)
         return resp, body
 
+    def list_lb_pool_stats(self, pool_id):
+        uri = '%s/lb/pools/%s/stats' % (self.uri_prefix, pool_id)
+        resp, body = self.get(uri)
+        body = _root_tag_fetcher_and_xml_to_json_parse(body)
+        return resp, body
+
 
 def _root_tag_fetcher_and_xml_to_json_parse(xml_returned_body):
     body = ET.fromstring(xml_returned_body)