Fix golang-ci linter errors (#10128)

* Fix golang-ci linter errors

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

* Fix gofmt errors

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

* Add nolint comment to defaults.Backend in Configuration

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

* Add #nosec comment to rand.New func

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

* Fix errcheck warnings

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

* Fix gofmt check

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

* Fix unit tests and comments

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

---------

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

cmd/dataplane/main.go

@@ -18,13 +18,10 @@ package main
 
 import (
 	"fmt"
-	"math/rand" // #nosec
-	"net/http"
-	"os"
-	"time"
-
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/collectors"
+	"net/http"
+	"os"
 
 	"k8s.io/klog/v2"
 
@@ -41,8 +38,6 @@ import (
 func main() {
 	klog.InitFlags(nil)
 
-	rand.Seed(time.Now().UnixNano())
-
 	fmt.Println(version.String())
 	var err error
 	showVersion, conf, err := ingressflags.ParseFlags()

cmd/nginx/main.go

@@ -19,7 +19,6 @@ package main
 import (
 	"context"
 	"fmt"
-	"math/rand" // #nosec
 	"net/http"
 	"os"
 	"path/filepath"
@@ -54,8 +53,6 @@ import (
 func main() {
 	klog.InitFlags(nil)
 
-	rand.Seed(time.Now().UnixNano())
-
 	fmt.Println(version.String())
 
 	showVersion, conf, err := ingressflags.ParseFlags()

cmd/plugin/commands/certs/certs.go

@@ -18,6 +18,7 @@ package certs
 
 import (
 	"fmt"
+	"os"
 
 	"github.com/spf13/cobra"
 
@@ -46,7 +47,10 @@ func CreateCommand(flags *genericclioptions.ConfigFlags) *cobra.Command {
 	}
 
 	cmd.Flags().String("host", "", "Get the cert for this hostname")
-	cobra.MarkFlagRequired(cmd.Flags(), "host")
+	if err := cobra.MarkFlagRequired(cmd.Flags(), "host"); err != nil {
+		util.PrintError(err)
+		os.Exit(1)
+	}
 	pod = util.AddPodFlag(cmd)
 	deployment = util.AddDeploymentFlag(cmd)
 	selector = util.AddSelectorFlag(cmd)

cmd/plugin/kubectl/kubectl.go

@@ -77,7 +77,9 @@ func execToWriter(args []string, writer io.Writer) error {
 		return err
 	}
 
-	go io.Copy(writer, op)
+	go func() {
+		io.Copy(writer, op) //nolint:errcheck
+	}()
 	err = cmd.Run()
 	if err != nil {
 		return err