Implement Prometheus metrics

metric/metric.go

@@ -0,0 +1,33 @@
+package metric
+
+import (
+	"fmt"
+	"github.com/TwinProduction/gatus/config"
+	"github.com/TwinProduction/gatus/core"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+	"strconv"
+	"sync"
+)
+
+var (
+	gauges = map[string]*prometheus.GaugeVec{}
+	rwLock sync.RWMutex
+)
+
+func PublishMetricsForService(service *core.Service, result *core.Result) {
+	if config.Get().Metrics {
+		rwLock.Lock()
+		gauge, exists := gauges[fmt.Sprintf("%s_%s", service.Name, service.Url)]
+		if !exists {
+			gauge = promauto.NewGaugeVec(prometheus.GaugeOpts{
+				Subsystem:   "gatus",
+				Name:        "tasks",
+				ConstLabels: prometheus.Labels{"service": service.Name, "url": service.Url},
+			}, []string{"status", "success"})
+			gauges[fmt.Sprintf("%s_%s", service.Name, service.Url)] = gauge
+		}
+		rwLock.Unlock()
+		gauge.WithLabelValues(strconv.Itoa(result.HttpStatus), strconv.FormatBool(result.Success)).Inc()
+	}
+}