Use metrics

nameserver/metrics.go

@@ -0,0 +1,21 @@
+package nameserver
+
+import (
+	"github.com/safing/portbase/api"
+	"github.com/safing/portbase/config"
+	"github.com/safing/portbase/metrics"
+)
+
+var requestsHistogram *metrics.Histogram
+
+func registerMetrics() (err error) {
+	requestsHistogram, err = metrics.NewHistogram(
+		"nameserver/request/duration/seconds",
+		nil,
+		&metrics.Options{
+			Permission:     api.PermitUser,
+			ExpertiseLevel: config.ExpertiseLevelExpert,
+		})
+
+	return err
+}

nameserver/module.go

@@ -33,7 +33,12 @@ func init() {
 }
 
 func prep() error {
-	return registerConfig()
+	err := registerConfig()
+	if err != nil {
+		return err
+	}
+
+	return registerMetrics()
 }
 
 func start() error {

nameserver/nameserver.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"net"
 	"strings"
+	"time"
 
 	"github.com/safing/portbase/log"
 	"github.com/safing/portmaster/firewall"
@@ -27,6 +28,10 @@ func handleRequestAsWorker(w dns.ResponseWriter, query *dns.Msg) {
 }
 
 func handleRequest(ctx context.Context, w dns.ResponseWriter, request *dns.Msg) error { //nolint:gocognit // TODO
+	// Record metrics.
+	startTime := time.Now()
+	defer requestsHistogram.UpdateDuration(startTime)
+
 	// Only process first question, that's how everyone does it.
 	if len(request.Question) == 0 {
 		return errors.New("missing question")