improve kube-vip cp lb auto-enable

pkg/minikube/bootstrapper/kubeadm/kubeadm.go

@@ -947,8 +947,9 @@ func (k *Bootstrapper) UpdateNode(cfg config.ClusterConfig, n config.Node, r cru
 	if n.ControlPlane {
 		// for primary control-plane node only, generate kubeadm config based on current params
 		// on node restart, it will be checked against later if anything needs changing
+		var kubeadmCfg []byte
 		if config.IsPrimaryControlPlane(cfg, n) {
-			kubeadmCfg, err := bsutil.GenerateKubeadmYAML(cfg, n, r)
+			kubeadmCfg, err = bsutil.GenerateKubeadmYAML(cfg, n, r)
 			if err != nil {
 				return errors.Wrap(err, "generating kubeadm cfg")
 			}
@@ -964,7 +965,7 @@ func (k *Bootstrapper) UpdateNode(cfg config.ClusterConfig, n config.Node, r cru
 				return errors.Wrapf(err, "parsing kubernetes version %q", cfg.KubernetesConfig.KubernetesVersion)
 			}
 			workaround := kv.GTE(semver.Version{Major: 1, Minor: 29}) && config.IsPrimaryControlPlane(cfg, n) && len(config.ControlPlanes(cfg)) == 1
-			kubevipCfg, err := kubevip.Configure(cfg, workaround)
+			kubevipCfg, err := kubevip.Configure(cfg, k.c, kubeadmCfg, workaround)
 			if err != nil {
 				klog.Errorf("couldn't generate kube-vip config, this might cause issues (will continue): %v", err)
 			} else {

pkg/minikube/cluster/ha/kube-vip/kube-vip.go

@@ -19,10 +19,14 @@ package kubevip
 import (
 	"bytes"
 	"html/template"
+	"os/exec"
+	"strings"
 
 	"github.com/pkg/errors"
 	"k8s.io/klog/v2"
+	"k8s.io/minikube/pkg/minikube/command"
 	"k8s.io/minikube/pkg/minikube/config"
+	"k8s.io/minikube/pkg/minikube/driver"
 )
 
 const Manifest = "kube-vip.yaml"
@@ -72,10 +76,12 @@ spec:
       value: {{ .VIP }}
     - name: prometheus_server
       value: :2112
+    {{- if .EnableLB }}
     - name : lb_enable
       value: "true"
     - name: lb_port
       value: "{{ .Port }}"
+    {{- end}}
     image: ghcr.io/kube-vip/kube-vip:v0.7.1
     imagePullPolicy: IfNotPresent
     name: kube-vip
@@ -101,17 +107,19 @@ status: {}
 `))
 
 // Configure takes last client ip address in cluster nodes network subnet as vip address and generates kube-vip.yaml file.
-func Configure(cc config.ClusterConfig, workaround bool) ([]byte, error) {
+func Configure(cc config.ClusterConfig, r command.Runner, kubeadmCfg []byte, workaround bool) ([]byte, error) {
 	klog.Info("generating kube-vip config ...")
 
 	params := struct {
 		VIP       string
 		Port      int
 		AdminConf string
+		EnableLB  bool
 	}{
 		VIP:       cc.KubernetesConfig.APIServerHAVIP,
 		Port:      cc.APIServerPort,
 		AdminConf: "/etc/kubernetes/admin.conf",
+		EnableLB:  enableCPLB(cc, r, kubeadmCfg),
 	}
 	if workaround {
 		params.AdminConf = "/etc/kubernetes/super-admin.conf"
@@ -126,3 +134,25 @@ func Configure(cc config.ClusterConfig, workaround bool) ([]byte, error) {
 
 	return b.Bytes(), nil
 }
+
+// enableCPLB auto-enables control-plane load-balancing, if possible - currently only possible with ipvs.
+// ref: https://kube-vip.io/docs/about/architecture/?query=ipvs#control-plane-load-balancing
+func enableCPLB(cc config.ClusterConfig, r command.Runner, kubeadmCfg []byte) bool {
+	// note known issue: "service lb with ipvs mode won't work with kubeproxy that is configured with ipvs mode"
+	// ref: https://kube-vip.io/docs/about/architecture/?query=ipvs#known-issues
+	// so we only want to enable control-plane load-balancing if kube-proxy mode is not set to ipvs
+	// ref: https://kubernetes.io/docs/reference/networking/virtual-ips/#proxy-mode-ipvs
+	if ipvs := strings.EqualFold(string(kubeadmCfg), "mode: ipvs"); ipvs {
+		klog.Info("giving up enabling control-plane load-balancing as kube-proxy mode appears to be set to ipvs")
+		return false
+	}
+	klog.Info("enabling control-plane load-balancing as kube-proxy mode appears not be set to ipvs")
+	// for vm driver, also ensure required ipvs kernel modules are loaded to enable kube-vip's control-plane load-balancing feature
+	// ref: https://github.com/kubernetes/kubernetes/blob/f90461c43e881d320b78d48793db10c110d488d1/pkg/proxy/ipvs/README.md?plain=1#L257-L269
+	if driver.IsVM(cc.Driver) {
+		if _, err := r.RunCmd(exec.Command("sudo", "sh", "-c", "modprobe --all ip_vs ip_vs_rr ip_vs_wrr ip_vs_sh nf_conntrack")); err != nil {
+			klog.Errorf("unable to load ipvs kernel modules: %v", err)
+		}
+	}
+	return true
+}

test/integration/ha_test.go

@@ -35,8 +35,8 @@ import (
 	"k8s.io/minikube/pkg/util/retry"
 )
 
-// TestMutliControlPlane tests all ha (multi-control plane) cluster functionality
+// TestMultiControlPlane tests all ha (multi-control plane) cluster functionality
-func TestMutliControlPlane(t *testing.T) {
+func TestMultiControlPlane(t *testing.T) {
 	if NoneDriver() {
 		t.Skip("none driver does not support multinode/ha(multi-control plane) cluster")
 	}