Add new stats metric

stats/stats_prometheus.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"net"
 	"net/http"
+	"strconv"
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
@@ -13,10 +14,11 @@ import (
 )
 
 type statsPrometheus struct {
-	connections *prometheus.GaugeVec
-	traffic     *prometheus.GaugeVec
-	crashes     prometheus.Gauge
-	antiReplays prometheus.Gauge
+	connections         *prometheus.GaugeVec
+	telegramConnections *prometheus.GaugeVec
+	traffic             *prometheus.GaugeVec
+	crashes             prometheus.Gauge
+	antiReplays         prometheus.Counter
 }
 
 func (s *statsPrometheus) IngressTraffic(traffic int) {
@@ -38,18 +40,39 @@ func (s *statsPrometheus) ClientDisconnected(connectionType conntypes.Connection
 func (s *statsPrometheus) changeConnections(connectionType conntypes.ConnectionType,
 	addr *net.TCPAddr,
 	increment float64) {
-	var labels [2]string
+	labels := [...]string{
+		"intermediate",
+		"ipv4",
+	}
 
 	switch connectionType {
 	case conntypes.ConnectionTypeAbridged:
 		labels[0] = "abridged"
 	case conntypes.ConnectionTypeSecure:
 		labels[0] = "secured"
-	default:
-		labels[0] = "intermediate"
 	}
 
-	labels[1] = "ipv4"
+	if addr.IP.To4() == nil {
+		labels[1] = "ipv6" // nolint: goconst
+	}
+
+	s.connections.WithLabelValues(labels[:]...).Add(increment)
+}
+
+func (s *statsPrometheus) TelegramConnected(dc conntypes.DC, addr *net.TCPAddr) {
+	s.changeTelegramConnections(dc, addr, 1.0)
+}
+
+func (s *statsPrometheus) TelegramDisconnected(dc conntypes.DC, addr *net.TCPAddr) {
+	s.changeTelegramConnections(dc, addr, -1.0)
+}
+
+func (s *statsPrometheus) changeTelegramConnections(dc conntypes.DC, addr *net.TCPAddr, increment float64) {
+	labels := [...]string{
+		strconv.Itoa(int(dc)),
+		"ipv4",
+	}
+
 	if addr.IP.To4() == nil {
 		labels[1] = "ipv6"
 	}
@@ -65,26 +88,32 @@ func (s *statsPrometheus) AntiReplayDetected() {
 	s.antiReplays.Inc()
 }
 
-func newStatsPrometheus(mux *http.ServeMux) (Stats, error) {
-	registry := prometheus.NewRegistry()
+func newStatsPrometheus(mux *http.ServeMux) (Interface, error) {
+	registry := prometheus.NewPedanticRegistry()
+
 	instance := &statsPrometheus{
 		connections: prometheus.NewGaugeVec(prometheus.GaugeOpts{
-			Namespace: config.C.PrometheusStats.Prefix,
+			Namespace: config.C.StatsNamespace,
 			Name:      "connections",
-			Help:      "Current number of connections to the proxy.",
+			Help:      "Current number of client connections to the proxy.",
 		}, []string{"type", "protocol"}),
+		telegramConnections: prometheus.NewGaugeVec(prometheus.GaugeOpts{
+			Namespace: config.C.StatsNamespace,
+			Name:      "telegram_connections",
+			Help:      "Current number of telegram connections established by this proxy.",
+		}, []string{"dc", "protocol"}),
 		traffic: prometheus.NewGaugeVec(prometheus.GaugeOpts{
-			Namespace: config.C.PrometheusStats.Prefix,
+			Namespace: config.C.StatsNamespace,
 			Name:      "traffic",
 			Help:      "Traffic passed through the proxy in bytes.",
 		}, []string{"direction"}),
 		crashes: prometheus.NewGauge(prometheus.GaugeOpts{
-			Namespace: config.C.PrometheusStats.Prefix,
+			Namespace: config.C.StatsNamespace,
 			Name:      "crashes",
 			Help:      "How many crashes happened.",
 		}),
-		antiReplays: prometheus.NewGauge(prometheus.GaugeOpts{
-			Namespace: config.C.PrometheusStats.Prefix,
+		antiReplays: prometheus.NewCounter(prometheus.CounterOpts{
+			Namespace: config.C.StatsNamespace,
 			Name:      "anti_replays",
 			Help:      "How many anti replay attacks were prevented.",
 		}),
@@ -104,7 +133,7 @@ func newStatsPrometheus(mux *http.ServeMux) (Stats, error) {
 	}
 
 	handler := promhttp.HandlerFor(registry, promhttp.HandlerOpts{})
-	mux.Handle("/prometheus", handler)
+	mux.Handle("/", handler)
 
 	return instance, nil
 }