BREAKING: Replace metrics

metric/metric.go

@@ -1,9 +1,7 @@
 package metric
 
 import (
-	"fmt"
 	"strconv"
-	"sync"
 
 	"github.com/TwiN/gatus/v3/core"
 	"github.com/prometheus/client_golang/prometheus"
@@ -11,24 +9,19 @@ import (
 )
 
 var (
-	gauges = map[string]*prometheus.GaugeVec{}
-	rwLock sync.RWMutex
+	// This will be initialized once PublishMetricsForEndpoint.
+	// The reason why we're doing this is that if metrics are disabled, we don't want to initialize it unnecessarily.
+	resultCount *prometheus.CounterVec = nil
 )
 
 // PublishMetricsForEndpoint publishes metrics for the given endpoint and its result.
 // These metrics will be exposed at /metrics if the metrics are enabled
 func PublishMetricsForEndpoint(endpoint *core.Endpoint, result *core.Result) {
-	rwLock.Lock()
-	gauge, exists := gauges[fmt.Sprintf("%s_%s", endpoint.Name, endpoint.URL)]
-	if !exists {
-		gauge = promauto.NewGaugeVec(prometheus.GaugeOpts{
-			Subsystem: "gatus",
-			Name:      "tasks",
-			// TODO: remove the "service" key in v4.0.0, as it is only kept for backward compatibility
-			ConstLabels: prometheus.Labels{"service": endpoint.Name, "endpoint": endpoint.Name, "url": endpoint.URL},
-		}, []string{"status", "success"})
-		gauges[fmt.Sprintf("%s_%s", endpoint.Name, endpoint.URL)] = gauge
+	if resultCount == nil {
+		resultCount = promauto.NewCounterVec(prometheus.CounterOpts{
+			Name: "gatus_results_total",
+			Help: "Number of results per endpoint",
+		}, []string{"key", "group", "name", "success"})
 	}
-	rwLock.Unlock()
-	gauge.WithLabelValues(strconv.Itoa(result.HTTPStatus), strconv.FormatBool(result.Success)).Inc()
+	resultCount.WithLabelValues(endpoint.Key(), endpoint.Group, endpoint.Name, strconv.FormatBool(result.Success)).Inc()
 }