refactor monitor apis to adopt new response format

pkg/client/heapsterclient.go

@@ -55,3 +55,23 @@ func GetHeapsterMetrics(url string) string {
 	}
 	return ""
 }
+func GetCAdvisorMetrics(nodeAddr string) string {
+
+	response, err := http.Get("http://" + nodeAddr + ":10255/stats/summary")
+	if err != nil {
+		glog.Error(err)
+		os.Exit(1)
+	} else {
+		defer response.Body.Close()
+
+		contents, err := ioutil.ReadAll(response.Body)
+
+		if err != nil {
+			glog.Error(err)
+			os.Exit(1)
+		}
+
+		return string(contents)
+	}
+	return ""
+}