[#1422] multinet: Add metrics

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

internal/metrics/multinet.go

@@ -0,0 +1,35 @@
+package metrics
+
+import (
+	"strconv"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-observability/metrics"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+type multinetMetrics struct {
+	dials *prometheus.GaugeVec
+}
+
+type MultinetMetrics interface {
+	Dial(sourceIP string, success bool)
+}
+
+func newMultinetMetrics(ns string) *multinetMetrics {
+	return &multinetMetrics{
+		dials: metrics.NewGaugeVec(
+			prometheus.GaugeOpts{
+				Namespace: ns,
+				Subsystem: multinetSubsystem,
+				Name:      "dial_count",
+				Help:      "Dials count performed by multinet",
+			}, []string{sourceIPLabel, successLabel}),
+	}
+}
+
+func (m *multinetMetrics) Dial(sourceIP string, success bool) {
+	m.dials.With(prometheus.Labels{
+		sourceIPLabel: sourceIP,
+		successLabel:  strconv.FormatBool(success),
+	}).Inc()
+}