Test case updated with alarm history api

Test case Updated

This is to check the functionality of alarm history api:
Fetch the history of specific alarm ID then verify that
create and update operation are reflected in result.

Change-Id: Ied3b7596e1c3ec9a45b1cb07299ffb4cdd0cf390
diff --git a/tempest/api/telemetry/test_telemetry_alarming_api.py b/tempest/api/telemetry/test_telemetry_alarming_api.py
index 13da9cb..6c84b98 100644
--- a/tempest/api/telemetry/test_telemetry_alarming_api.py
+++ b/tempest/api/telemetry/test_telemetry_alarming_api.py
@@ -56,18 +56,24 @@
                     'comparison_operator': 'eq',
                     'threshold': 70.0,
                     'period': 60}
-        alarm_name = data_utils.rand_name('telemetry-alarm-update')
+        alarm_name_updated = data_utils.rand_name('telemetry-alarm-update')
         body = self.telemetry_client.update_alarm(
             alarm_id,
             threshold_rule=new_rule,
-            name=alarm_name,
+            name=alarm_name_updated,
             type='threshold')
-        self.assertEqual(alarm_name, body['name'])
+        self.assertEqual(alarm_name_updated, body['name'])
         self.assertDictContainsSubset(new_rule, body['threshold_rule'])
         # Get and verify details of an alarm after update
         body = self.telemetry_client.show_alarm(alarm_id)
-        self.assertEqual(alarm_name, body['name'])
+        self.assertEqual(alarm_name_updated, body['name'])
         self.assertDictContainsSubset(new_rule, body['threshold_rule'])
+        # Get history for the alarm and verify the same
+        body = self.telemetry_client.show_alarm_history(alarm_id)
+        self.assertEqual("rule change", body[0]['type'])
+        self.assertIn(alarm_name_updated, body[0]['detail'])
+        self.assertEqual("creation", body[1]['type'])
+        self.assertIn(alarm_name, body[1]['detail'])
         # Delete alarm and verify if deleted
         self.telemetry_client.delete_alarm(alarm_id)
         self.assertRaises(lib_exc.NotFound,
diff --git a/tempest/services/telemetry/json/telemetry_client.py b/tempest/services/telemetry/json/telemetry_client.py
index 1f181e3..fc8951e 100644
--- a/tempest/services/telemetry/json/telemetry_client.py
+++ b/tempest/services/telemetry/json/telemetry_client.py
@@ -140,3 +140,10 @@
         self.expected_success(200, resp.status)
         body = self.deserialize(body)
         return service_client.ResponseBodyData(resp, body)
+
+    def show_alarm_history(self, alarm_id):
+        uri = "%s/alarms/%s/history" % (self.uri_prefix, alarm_id)
+        resp, body = self.get(uri)
+        self.expected_success(200, resp.status)
+        body = self.deserialize(body)
+        return service_client.ResponseBodyList(resp, body)