refactor(metrics): Rename metric to metrics

metrics/metrics.go

@@ -0,0 +1,73 @@
+package metrics
+
+import (
+	"strconv"
+
+	"github.com/TwiN/gatus/v3/core"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+const namespace = "gatus" // The prefix of the metrics
+
+var (
+	initializedMetrics bool // Whether the metrics have been initialized
+
+	resultTotal                        *prometheus.CounterVec
+	resultDurationSeconds              *prometheus.GaugeVec
+	resultConnectedTotal               *prometheus.CounterVec
+	resultCodeTotal                    *prometheus.CounterVec
+	resultCertificateExpirationSeconds *prometheus.GaugeVec
+)
+
+func initializePrometheusMetrics() {
+	resultTotal = promauto.NewCounterVec(prometheus.CounterOpts{
+		Namespace: namespace,
+		Name:      "results_total",
+		Help:      "Number of results per endpoint",
+	}, []string{"key", "group", "name", "type", "success"})
+	resultDurationSeconds = promauto.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: namespace,
+		Name:      "results_duration_seconds",
+		Help:      "Duration of the request in seconds",
+	}, []string{"key", "group", "name", "type"})
+	resultConnectedTotal = promauto.NewCounterVec(prometheus.CounterOpts{
+		Namespace: namespace,
+		Name:      "results_connected_total",
+		Help:      "Total number of results in which a connection was successfully established",
+	}, []string{"key", "group", "name", "type"})
+	resultCodeTotal = promauto.NewCounterVec(prometheus.CounterOpts{
+		Namespace: namespace,
+		Name:      "results_code_total",
+		Help:      "Total number of results by code",
+	}, []string{"key", "group", "name", "type", "code"})
+	resultCertificateExpirationSeconds = promauto.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: namespace,
+		Name:      "results_certificate_expiration_seconds",
+		Help:      "Number of seconds until the certificate expires",
+	}, []string{"key", "group", "name", "type"})
+}
+
+// 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) {
+	if !initializedMetrics {
+		initializePrometheusMetrics()
+		initializedMetrics = true
+	}
+	endpointType := endpoint.Type()
+	resultTotal.WithLabelValues(endpoint.Key(), endpoint.Group, endpoint.Name, string(endpointType), strconv.FormatBool(result.Success)).Inc()
+	resultDurationSeconds.WithLabelValues(endpoint.Key(), endpoint.Group, endpoint.Name, string(endpointType)).Set(result.Duration.Seconds())
+	if result.Connected {
+		resultConnectedTotal.WithLabelValues(endpoint.Key(), endpoint.Group, endpoint.Name, string(endpointType)).Inc()
+	}
+	if result.DNSRCode != "" {
+		resultCodeTotal.WithLabelValues(endpoint.Key(), endpoint.Group, endpoint.Name, string(endpointType), result.DNSRCode).Inc()
+	}
+	if result.HTTPStatus != 0 {
+		resultCodeTotal.WithLabelValues(endpoint.Key(), endpoint.Group, endpoint.Name, string(endpointType), strconv.Itoa(result.HTTPStatus)).Inc()
+	}
+	if result.CertificateExpiration != 0 {
+		resultCertificateExpirationSeconds.WithLabelValues(endpoint.Key(), endpoint.Group, endpoint.Name, string(endpointType)).Set(result.CertificateExpiration.Seconds())
+	}
+}