Fix unit tests and comments

Signed-off-by: z1cheng <imchench@gmail.com>

internal/ingress/controller/checker_test.go

@@ -103,9 +103,7 @@ func TestNginxCheck(t *testing.T) {
 				}
 			}()
 			go func() {
-				if err := cmd.Wait(); err != nil {
-					t.Errorf("unexpected error waiting for the process: %v", err)
-				}
+				cmd.Wait() //nolint:errcheck
 			}()
 
 			if _, err := pidFile.Write([]byte(fmt.Sprintf("%v", pid))); err != nil {
@@ -123,9 +121,7 @@ func TestNginxCheck(t *testing.T) {
 			})
 
 			// pollute pid file
-			if _, err := pidFile.Write([]byte("999999")); err != nil {
-				t.Errorf("unexpected error polluting the pid file: %v", err)
-			}
+			pidFile.Write([]byte("999999")) //nolint:errcheck
 			pidFile.Close()
 
 			t.Run("bad pid", func(t *testing.T) {

internal/ingress/controller/store/store_test.go

@@ -92,11 +92,7 @@ func TestStore(t *testing.T) {
 
 	emptySelector, _ := labels.Parse("")
 
-	defer func() {
-		if err := te.Stop(); err != nil {
-			t.Errorf("error: %v", err)
-		}
-	}()
+	defer te.Stop() //nolint:errcheck
 
 	clientSet, err := kubernetes.NewForConfig(cfg)
 	if err != nil {

internal/ingress/controller/template/template.go

@@ -18,13 +18,14 @@ package template
 
 import (
 	"bytes"
+	"crypto/rand"
 	"crypto/sha1" // #nosec
 	"encoding/base64"
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
 	"io"
-	"math/rand" // #nosec
+	"math/big"
 	"net"
 	"net/url"
 	"os"
@@ -34,7 +35,6 @@ import (
 	"strconv"
 	"strings"
 	text_template "text/template"
-	"time"
 
 	networkingv1 "k8s.io/api/networking/v1"
 	"k8s.io/apimachinery/pkg/util/sets"
@@ -1186,16 +1186,16 @@ func buildAuthSignURLLocation(location, authSignURL string) string {
 }
 
 var letters = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
-var random *rand.Rand
-
-func init() {
-	random = rand.New(rand.NewSource(time.Now().UnixNano())) // #nosec
-}
 
 func randomString() string {
 	b := make([]rune, 32)
 	for i := range b {
-		b[i] = letters[random.Intn(len(letters))] // #nosec
+		idx, err := rand.Int(rand.Reader, big.NewInt(int64(len(letters))))
+		if err != nil {
+			klog.Errorf("unexpected error generating random index: %v", err)
+			return ""
+		}
+		b[i] = letters[idx.Int64()]
 	}
 
 	return string(b)

internal/ingress/metric/collectors/process_test.go

@@ -48,10 +48,7 @@ func TestProcessCollector(t *testing.T) {
 
 			done := make(chan struct{})
 			go func() {
-				err = cmd.Wait()
-				if err != nil {
-					t.Errorf("unexpected error waiting for dummy process: %v", err)
-				}
+				cmd.Wait() //nolint:errcheck
 				status := cmd.ProcessState.Sys().(syscall.WaitStatus)
 				if status.Signaled() {
 					t.Logf("Signal: %v", status.Signal())
@@ -72,11 +69,8 @@ func TestProcessCollector(t *testing.T) {
 			defer func() {
 				cm.Stop()
 
-				err = cmd.Process.Kill()
+				cmd.Process.Kill() //nolint:errcheck
 				<-done
-				if err != nil {
-					t.Errorf("unexpected error killing dummy process: %v", err)
-				}
 				close(done)
 			}()