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

@@ -276,7 +276,7 @@ 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/cli/cmds/server.go

@@ -190,7 +190,7 @@ var ServerFlags = []cli.Flag{
 	},
 	&cli.StringFlag{
 		Name:        "advertise-address",
-		Usage:       "(listener) IPv4 address that apiserver uses to advertise to members of the cluster (default: node-external-ip/node-ip)",
+		Usage:       "(listener) IPv4/IPv6 address that apiserver uses to advertise to members of the cluster (default: node-external-ip/node-ip)",
 		Destination: &ServerConfig.AdvertiseIP,
 	},
 	&cli.IntFlag{

pkg/daemons/agent/agent_linux.go

@@ -4,6 +4,7 @@
 package agent
 
 import (
+	"net"
 	"os"
 	"path/filepath"
 	"strings"
@@ -13,8 +14,8 @@ import (
 	"github.com/k3s-io/k3s/pkg/util"
 	"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://"
@@ -32,8 +33,8 @@ 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{
@@ -53,8 +54,8 @@ 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{
@@ -122,9 +123,12 @@ 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["feature-gates"] = util.AddFeatureGate(argsMap["feature-gates"], "CloudDualStackNodeIPs=true")
+		}
+		argsMap["node-ip"] = nodeIPs
 	}
 	kubeletRoot, runtimeRoot, controllers := cgroups.CheckCgroups()
 	if !controllers["cpu"] {

tests/e2e/dualstack/Vagrantfile

@@ -50,7 +50,6 @@ def provision(vm, role, role_num, node_num)
         service-cidr: 10.43.0.0/16,2001:cafe:42:1::/112
         bind-address: #{NETWORK4_PREFIX}.100
         flannel-iface: eth1
-        kubelet-arg: "--node-ip=0.0.0.0" # Workaround for https://github.com/kubernetes/kubernetes/issues/111695 
       YAML
       k3s.env = ["K3S_KUBECONFIG_MODE=0644", install_type]
     end
@@ -66,7 +65,6 @@ def provision(vm, role, role_num, node_num)
         cluster-cidr: 10.42.0.0/16,2001:cafe:42:0::/56
         service-cidr: 10.43.0.0/16,2001:cafe:42:1::/112
         flannel-iface: eth1
-        kubelet-arg: "--node-ip=0.0.0.0" # Workaround for https://github.com/kubernetes/kubernetes/issues/111695
       YAML
       k3s.env = ["K3S_KUBECONFIG_MODE=0644", install_type]
     end
@@ -81,7 +79,6 @@ def provision(vm, role, role_num, node_num)
         server: https://#{NETWORK4_PREFIX}.100:6443
         token: vagrant
         flannel-iface: eth1
-        kubelet-arg: "--node-ip=0.0.0.0" # Workaround for https://github.com/kubernetes/kubernetes/issues/111695
       YAML
       k3s.env = ["K3S_KUBECONFIG_MODE=0644", install_type]
     end