use pkg/reuseport in rest plugins (#3492)

Automatically submitted.

plugin/dnstap/dnstapio/io_test.go

@@ -6,6 +6,8 @@ import (
 	"testing"
 	"time"
 
+	"github.com/coredns/coredns/plugin/pkg/reuseport"
+	
 	tap "github.com/dnstap/golang-dnstap"
 	fs "github.com/farsightsec/golang-framestream"
 )
@@ -55,7 +57,7 @@ func TestTransport(t *testing.T) {
 
 	for _, param := range transport {
 		// Start TCP listener
-		l, err := net.Listen(param[0], param[1])
+		l, err := reuseport.Listen(param[0], param[1])
 		if err != nil {
 			t.Fatalf("Cannot start listener: %s", err)
 		}
@@ -82,7 +84,7 @@ func TestRace(t *testing.T) {
 	count := 10
 
 	// Start TCP listener
-	l, err := net.Listen("tcp", endpointTCP)
+	l, err := reuseport.Listen("tcp", endpointTCP)
 	if err != nil {
 		t.Fatalf("Cannot start listener: %s", err)
 	}
@@ -115,7 +117,7 @@ func TestReconnect(t *testing.T) {
 	count := 5
 
 	// Start TCP listener
-	l, err := net.Listen("tcp", endpointTCP)
+	l, err := reuseport.Listen("tcp", endpointTCP)
 	if err != nil {
 		t.Fatalf("Cannot start listener: %s", err)
 	}
@@ -141,7 +143,7 @@ func TestReconnect(t *testing.T) {
 	l.Close()
 
 	// And start TCP listener again on the same port
-	l, err = net.Listen("tcp", addr)
+	l, err = reuseport.Listen("tcp", addr)
 	if err != nil {
 		t.Fatalf("Cannot start listener: %s", err)
 	}

plugin/metrics/metrics.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/coredns/coredns/plugin"
 	"github.com/coredns/coredns/plugin/metrics/vars"
+	"github.com/coredns/coredns/plugin/pkg/reuseport"
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
@@ -95,7 +96,7 @@ func (m *Metrics) ZoneNames() []string {
 
 // OnStartup sets up the metrics on startup.
 func (m *Metrics) OnStartup() error {
-	ln, err := net.Listen("tcp", m.Addr)
+	ln, err := reuseport.Listen("tcp", m.Addr)
 	if err != nil {
 		log.Errorf("Failed to start metrics handler: %s", err)
 		return err

plugin/pkg/dnstest/server.go

@@ -3,6 +3,8 @@ package dnstest
 import (
 	"net"
 
+	"github.com/coredns/coredns/plugin/pkg/reuseport"
+
 	"github.com/miekg/dns"
 )
 
@@ -27,7 +29,7 @@ func NewServer(f dns.HandlerFunc) *Server {
 	s2 := &dns.Server{} // tcp
 
 	for i := 0; i < 5; i++ { // 5 attempts
-		s2.Listener, _ = net.Listen("tcp", ":0")
+		s2.Listener, _ = reuseport.Listen("tcp", ":0")
 		if s2.Listener == nil {
 			continue
 		}