Use IPv6 in case is the first configured IP with dualstack

pkg/agent/config/config.go

@@ -353,7 +353,7 @@ func get(ctx context.Context, envInfo *cmds.Agent, proxy proxy.Proxy) (*config.N
 
 	// If the supervisor and externally-facing apiserver are not on the same port, tell the proxy where to find the apiserver.
 	if controlConfig.SupervisorPort != controlConfig.HTTPSPort {
-		_, isIPv6, _ := util.GetFirstString([]string{envInfo.NodeIP.String()})
+		isIPv6 := utilsnet.IsIPv6(net.ParseIP([]string{envInfo.NodeIP.String()}[0]))
 		if err := proxy.SetAPIServerPort(ctx, controlConfig.HTTPSPort, isIPv6); err != nil {
 			return nil, errors.Wrapf(err, "failed to setup access to API Server port %d on at %s", controlConfig.HTTPSPort, proxy.SupervisorURL())
 		}

pkg/agent/run.go

@@ -277,7 +277,7 @@ func createProxyAndValidateToken(ctx context.Context, cfg *cmds.Agent) (proxy.Pr
 	if err := os.MkdirAll(agentDir, 0700); err != nil {
 		return nil, err
 	}
-	_, isIPv6, _ := util.GetFirstString([]string{cfg.NodeIP.String()})
+	isIPv6 := utilsnet.IsIPv6(net.ParseIP([]string{cfg.NodeIP.String()}[0]))
 
 	proxy, err := proxy.NewSupervisorProxy(ctx, !cfg.DisableLoadBalancer, agentDir, cfg.ServerURL, cfg.LBServerPort, isIPv6)
 	if err != nil {

pkg/daemons/agent/agent_linux.go

@@ -4,6 +4,7 @@
 package agent
 
 import (
+	"net"
 	"os"
 	"path/filepath"
 	"strings"
@@ -14,8 +15,8 @@ import (
 	"github.com/opencontainers/runc/libcontainer/userns"
 	"github.com/sirupsen/logrus"
 	"golang.org/x/sys/unix"
-	"k8s.io/apimachinery/pkg/util/net"
 	"k8s.io/kubernetes/pkg/kubeapiserver/authorizer/modes"
+	utilsnet "k8s.io/utils/net"
 )
 
 const socketPrefix = "unix://"
@@ -33,8 +34,8 @@ func createRootlessConfig(argsMap map[string]string, controllers map[string]bool
 
 func kubeProxyArgs(cfg *config.Agent) map[string]string {
 	bindAddress := "127.0.0.1"
-	_, IPv6only, _ := util.GetFirstString([]string{cfg.NodeIP})
-	if IPv6only {
+	isIPv6 := utilsnet.IsIPv6(net.ParseIP([]string{cfg.NodeIP}[0]))
+	if isIPv6 {
 		bindAddress = "::1"
 	}
 	argsMap := map[string]string{
@@ -54,8 +55,8 @@ func kubeProxyArgs(cfg *config.Agent) map[string]string {
 
 func kubeletArgs(cfg *config.Agent) map[string]string {
 	bindAddress := "127.0.0.1"
-	_, IPv6only, _ := util.GetFirstString([]string{cfg.NodeIP})
-	if IPv6only {
+	isIPv6 := utilsnet.IsIPv6(net.ParseIP([]string{cfg.NodeIP}[0]))
+	if isIPv6 {
 		bindAddress = "::1"
 	}
 	argsMap := map[string]string{
@@ -123,9 +124,11 @@ func kubeletArgs(cfg *config.Agent) map[string]string {
 	if cfg.NodeName != "" {
 		argsMap["hostname-override"] = cfg.NodeName
 	}
-	defaultIP, err := net.ChooseHostInterface()
-	if err != nil || defaultIP.String() != cfg.NodeIP {
-		argsMap["node-ip"] = cfg.NodeIP
+	if nodeIPs := util.JoinIPs(cfg.NodeIPs); nodeIPs != "" {
+		dualStack, err := utilsnet.IsDualStackIPs(cfg.NodeIPs)
+		if err == nil && !dualStack {
+			argsMap["node-ip"] = cfg.NodeIP
+		}
 	}
 	kubeletRoot, runtimeRoot, controllers := cgroups.CheckCgroups()
 	if !controllers["cpu"] {