Add initial support for Kubernetes 1.28 (#2948)

Signed-off-by: Marko Mudrinić <mudrinic.mare@gmail.com>

Makefile

@@ -37,7 +37,7 @@ export CGO_ENABLED=0
 export GOPROXY?=https://proxy.golang.org
 export GO111MODULE=on
 export GOFLAGS?=-mod=readonly -trimpath
-export DEFAULT_STABLE=$(shell curl -SsL https://dl.k8s.io/release/stable-1.27.txt)
+export DEFAULT_STABLE=$(shell curl -SsL https://dl.k8s.io/release/stable-1.28.txt)
 
 BUILD_DATE=$(shell if hash gdate 2>/dev/null; then gdate --rfc-3339=seconds | sed 's/ /T/'; else date --rfc-3339=seconds | sed 's/ /T/'; fi)
 GITCOMMIT=$(shell git log -1 --pretty=format:"%H")

pkg/apis/kubeone/helpers.go

@@ -241,6 +241,12 @@ func (crc ContainerRuntimeConfig) CRISocket() string {
 	return ""
 }
 
+// SandboxImage is used to determine the pause image version that should be used,
+// depending on the desired Kubernetes version. It's important to use the same
+// pause image version for both container runtime and kubeadm to avoid issues.
+// Values come from:
+//   - https://github.com/kubernetes/kubernetes/blob/master/cmd/kubeadm/app/constants/constants.go#L423
+//   - https://github.com/containerd/containerd/blob/main/pkg/cri/config/config_unix.go#L90
 func (v VersionConfig) SandboxImage(imageRegistry func(string) string) (string, error) {
 	kubeSemVer, err := semver.NewVersion(v.Kubernetes)
 	if err != nil {

pkg/apis/kubeone/validation/validation.go

@@ -41,7 +41,7 @@ const (
 	// lowerVersionConstraint defines a semver constraint that validates Kubernetes versions against a lower bound
 	lowerVersionConstraint = ">= 1.25"
 	// upperVersionConstraint defines a semver constraint that validates Kubernetes versions against an upper bound
-	upperVersionConstraint = "<= 1.27"
+	upperVersionConstraint = "<= 1.28"
 	// gte125VersionConstraint defines a semver constraint that validates Kubernetes versions >= 1.25
 	gte125VersionConstraint = ">= 1.25"
 )

pkg/kubeflags/data.go

@@ -17,7 +17,7 @@ limitations under the License.
 package kubeflags
 
 var (
-	defaultAdmissionControllersv1227 = []string{
+	defaultAdmissionControllersv1227v1228 = []string{
 		"NamespaceLifecycle",
 		"LimitRanger",
 		"ServiceAccount",

pkg/kubeflags/flags.go

@@ -38,6 +38,6 @@ func DefaultAdmissionControllers(v *semver.Version) string {
 	case v126Constraint.Check(v):
 		return strings.Join(defaultAdmissionControllersv1226, ",")
 	default:
-		return strings.Join(defaultAdmissionControllersv1227, ",")
+		return strings.Join(defaultAdmissionControllersv1227v1228, ",")
 	}
 }