add account balance metric

core/daemon.go

@@ -187,5 +187,6 @@ func (d Daemon) updateMetrics(ch chan jobStatus) func() {
 				UpdateOrdersPlaced(dish.OrderId, dish.Dish.Name, dish.Orders)
 			}
 		}
+
 	}
 }

core/metrics.go

@@ -1,26 +1,37 @@
 package core
 
 import (
+	"fmt"
 	"net/http"
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 )
 
-// ordersPlaced is a Prometheus counter metric.
 var dishOrders = prometheus.NewGaugeVec(prometheus.GaugeOpts{
 	Name: "total_orders_per_dish",
-	Help: "Total number of orders per dish orderID"},
-	[]string{"OrderId", "DishName"},
+	Help: "Total number of orders per dish"},
+	[]string{"order_id", "dish_name"},
+)
+
+var accountBalance = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+	Name: "account_balance",
+	Help: "Account balance in cent"},
+	[]string{"user_id", "user_name"},
 )
 
 func init() {
 	// Register metrics with Prometheus's default registry.
 	prometheus.MustRegister(dishOrders)
+	prometheus.MustRegister(accountBalance)
 }
 
 func UpdateOrdersPlaced(OrderId int, DishName string, NumOrders int) {
-	dishOrders.With(prometheus.Labels{"dish": DishName}).Set(float64(NumOrders))
+	dishOrders.With(prometheus.Labels{"order_id": fmt.Sprint(OrderId), "dish_name": DishName}).Set(float64(NumOrders))
+}
+
+func UpdateAccountBalance(UserId int, UserName string, Balance int) {
+	accountBalance.With(prometheus.Labels{"user_id": fmt.Sprint(UserId), "user_name": UserName}).Set(float64(Balance))
 }
 
 // GetPrometheusHandler returns the HTTP handler for Prometheus metrics.