fix(init): allow custom image for kubeadm (#212)

src/initramfs/cmd/init/pkg/system/services/kubeadm.go

@@ -153,6 +153,14 @@ func (k *Kubeadm) ConditionFunc(data *userdata.UserData) conditions.ConditionFun
 // Start implements the Service interface.
 // nolint: dupl
 func (k *Kubeadm) Start(data *userdata.UserData) error {
+	// Set the image.
+	var image string
+	if data.Services.Kubeadm != nil && data.Services.Kubeadm.Image != "" {
+		image = data.Services.Kubeadm.Image
+	} else {
+		image = constants.KubernetesImage
+	}
+
 	// We only wan't to run kubeadm if it hasn't been ran already.
 	if _, err := os.Stat("/var/etc/kubernetes/kubelet.conf"); !os.IsNotExist(err) {
 		return nil
@@ -189,7 +197,7 @@ func (k *Kubeadm) Start(data *userdata.UserData) error {
 	return r.Run(
 		data,
 		args,
-		runner.WithContainerImage(constants.KubernetesImage),
+		runner.WithContainerImage(image),
 		runner.WithOCISpecOpts(
 			containerd.WithMemoryLimit(int64(1000000*512)),
 			containerd.WithRootfsPropagation("slave"),

src/initramfs/pkg/userdata/userdata.go

@@ -84,6 +84,7 @@ type Kubelet struct {
 
 // Kubeadm describes the set of configuration options available for kubeadm.
 type Kubeadm struct {
+	Image         string         `yaml:"image,omitempty"`
 	Configuration runtime.Object `yaml:"configuration"`
 	bootstrap     bool
 	controlPlane  bool