Remove k8s.io/kubernetes dependency

internal/ingress/controller/controller.go

@@ -43,7 +43,6 @@ import (
 	"k8s.io/ingress-nginx/internal/k8s"
 	"k8s.io/ingress-nginx/internal/nginx"
 	"k8s.io/klog/v2"
-	"k8s.io/kubernetes/pkg/apis/core"
 )
 
 const (
@@ -155,7 +154,7 @@ func (n *NGINXController) syncIngress(interface{}) error {
 			n.metricCollector.IncReloadErrorCount()
 			n.metricCollector.ConfigSuccess(hash, false)
 			klog.Errorf("Unexpected failure reloading the backend:\n%v", err)
-			n.recorder.Eventf(k8s.IngressNGINXPod, core.EventTypeWarning, "RELOAD", fmt.Sprintf("Error reloading NGINX: %v", err))
+			n.recorder.Eventf(k8s.IngressNGINXPod, apiv1.EventTypeWarning, "RELOAD", fmt.Sprintf("Error reloading NGINX: %v", err))
 			return err
 		}
 
@@ -163,7 +162,7 @@ func (n *NGINXController) syncIngress(interface{}) error {
 		n.metricCollector.ConfigSuccess(hash, true)
 		n.metricCollector.IncReloadCount()
 
-		n.recorder.Eventf(k8s.IngressNGINXPod, core.EventTypeNormal, "RELOAD", "NGINX reload triggered due to a change in configuration")
+		n.recorder.Eventf(k8s.IngressNGINXPod, apiv1.EventTypeNormal, "RELOAD", "NGINX reload triggered due to a change in configuration")
 	}
 
 	isFirstSync := n.runningConfig.Equal(&ingress.Configuration{})

internal/ingress/controller/util.go

@@ -18,15 +18,18 @@ package controller
 
 import (
 	"fmt"
+	"io/ioutil"
 	"os"
 	"os/exec"
+	"path"
+	"strconv"
+	"strings"
 	"syscall"
 
 	api "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/util/intstr"
 	"k8s.io/ingress-nginx/internal/ingress"
 	"k8s.io/klog/v2"
-	"k8s.io/kubernetes/pkg/util/sysctl"
 )
 
 // newUpstream creates an upstream without servers.
@@ -52,7 +55,7 @@ func upstreamName(namespace string, service string, port intstr.IntOrString) str
 // for acceptance (value of net.core.somaxconn)
 // http://nginx.org/en/docs/http/ngx_http_core_module.html#listen
 func sysctlSomaxconn() int {
-	maxConns, err := sysctl.New().GetSysctl("net/core/somaxconn")
+	maxConns, err := getSysctl("net/core/somaxconn")
 	if err != nil || maxConns < 512 {
 		klog.V(3).InfoS("Using default net.core.somaxconn", "value", maxConns)
 		return 511
@@ -117,3 +120,18 @@ func (nc NginxCommand) ExecCommand(args ...string) *exec.Cmd {
 func (nc NginxCommand) Test(cfg string) ([]byte, error) {
 	return exec.Command(nc.Binary, "-c", cfg, "-t").CombinedOutput()
 }
+
+// getSysctl returns the value for the specified sysctl setting
+func getSysctl(sysctl string) (int, error) {
+	data, err := ioutil.ReadFile(path.Join("/proc/sys", sysctl))
+	if err != nil {
+		return -1, err
+	}
+
+	val, err := strconv.Atoi(strings.Trim(string(data), " \n"))
+	if err != nil {
+		return -1, err
+	}
+
+	return val, nil
+}

internal/ingress/status/status.go

@@ -34,7 +34,6 @@ import (
 	"k8s.io/apimachinery/pkg/labels"
 	"k8s.io/apimachinery/pkg/util/wait"
 	clientset "k8s.io/client-go/kubernetes"
-	"k8s.io/kubernetes/pkg/kubelet/util/sliceutils"
 
 	"k8s.io/ingress-nginx/internal/ingress"
 	"k8s.io/ingress-nginx/internal/k8s"
@@ -208,7 +207,7 @@ func (s *statusSync) runningAddresses() ([]string, error) {
 		}
 
 		name := k8s.GetNodeIPOrName(s.Client, pod.Spec.NodeName, s.UseNodeInternalIP)
-		if !sliceutils.StringInSlice(name, addrs) {
+		if !stringInSlice(name, addrs) {
 			addrs = append(addrs, name)
 		}
 	}
@@ -365,3 +364,14 @@ func statusAddressFromService(service string, kubeClient clientset.Interface) ([
 
 	return nil, fmt.Errorf("unable to extract IP address/es from service %v", service)
 }
+
+// stringInSlice returns true if s is in list
+func stringInSlice(s string, list []string) bool {
+	for _, v := range list {
+		if v == s {
+			return true
+		}
+	}
+
+	return false
+}