fixed some linter warnings

cmd/resolve/main_test.go

@@ -7,7 +7,6 @@ package main
 import (
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"net"
 	"os"
@@ -114,17 +113,17 @@ func compareParams(got, expected *params) bool {
 }
 
 func TestSetupFiles(t *testing.T) {
-	logfile, err := ioutil.TempFile("", "log")
+	logfile, err := os.CreateTemp("", "log")
 	if err != nil {
 		t.Fatalf("Failed to open the temporary log file: %v", err)
 	}
 
-	output, err := ioutil.TempFile("", "output")
+	output, err := os.CreateTemp("", "output")
 	if err != nil {
 		t.Fatalf("Failed to open the temporary output file: %v", err)
 	}
 
-	input, err := ioutil.TempFile("", "input")
+	input, err := os.CreateTemp("", "input")
 	if err != nil {
 		t.Fatalf("Failed to open the temporary input file: %v", err)
 	}
@@ -248,7 +247,7 @@ func TestEventLoop(t *testing.T) {
 
 	output, _ := os.Open(os.DevNull)
 	p := &params{
-		Log:     log.New(ioutil.Discard, "", 0),
+		Log:     log.New(io.Discard, "", 0),
 		QPS:     10,
 		Qtypes:  []uint16{dns.TypeA},
 		Output:  output,

conn.go

@@ -92,7 +92,7 @@ func (c *connections) WriteMsg(msg *dns.Msg, addr *net.UDPAddr) error {
 	if out, err = msg.Pack(); err == nil {
 		conn := c.Next()
 
-		conn.SetWriteDeadline(time.Now().Add(500 * time.Millisecond))
+		_ = conn.SetWriteDeadline(time.Now().Add(500 * time.Millisecond))
 		if n, err = conn.WriteToUDP(out, addr); err == nil && n < len(out) {
 			err = fmt.Errorf("only wrote %d bytes of the %d byte message", n, len(out))
 		}

conn_test.go

@@ -32,7 +32,7 @@ func TestConnections(t *testing.T) {
 		msg := QueryMsg(name, 1)
 
 		if addr, err := net.ResolveUDPAddr("udp", addrstr); err == nil {
-			conn.WriteMsg(msg, addr)
+			_ = conn.WriteMsg(msg, addr)
 		}
 		if i%10 == 0 {
 			time.Sleep(100 * time.Millisecond)

rate.go

@@ -15,7 +15,7 @@ import (
 )
 
 const (
-	maxQPSPerNameserver  = 500
+	maxQPSPerNameserver  = 100
 	numIntervalSeconds   = 2
 	rateUpdateInterval   = numIntervalSeconds * time.Second
 	maxTimeoutPercentage = 0.1