Allow to drop useExperimentalRetryJoin field from KubeadmControlPlane.kubeadmConfigSpec

Author: MaxFedotov

controlplane/kubeadm/api/v1beta1/kubeadm_control_plane_webhook.go

@@ -140,6 +140,7 @@ func (in *KubeadmControlPlane) ValidateUpdate(old runtime.Object) (admission.War
 	// For example, {"spec", "*"} will allow any path under "spec" to change.
 	allowedPaths := [][]string{
 		{"metadata", "*"},
+		{spec, kubeadmConfigSpec, "useExperimentalRetryJoin"},
 		{spec, kubeadmConfigSpec, clusterConfiguration, "etcd", "local", "imageRepository"},
 		{spec, kubeadmConfigSpec, clusterConfiguration, "etcd", "local", "imageTag"},
 		{spec, kubeadmConfigSpec, clusterConfiguration, "etcd", "local", "extraArgs"},

controlplane/kubeadm/api/v1beta1/kubeadm_control_plane_webhook_test.go

@@ -698,6 +698,11 @@ func TestKubeadmControlPlaneValidateUpdate(t *testing.T) {
 		"/invalid-key": "foo",
 	}
 
+	beforeUseExperimentalRetryJoin := before.DeepCopy()
+	beforeUseExperimentalRetryJoin.Spec.KubeadmConfigSpec.UseExperimentalRetryJoin = true //nolint:staticcheck
+	updateUseExperimentalRetryJoin := before.DeepCopy()
+	updateUseExperimentalRetryJoin.Spec.KubeadmConfigSpec.UseExperimentalRetryJoin = false //nolint:staticcheck
+
 	tests := []struct {
 		name                  string
 		enableIgnitionFeature bool
@@ -1050,6 +1055,12 @@ func TestKubeadmControlPlaneValidateUpdate(t *testing.T) {
 			before:                before,
 			kcp:                   invalidMetadata,
 		},
+		{
+			name:      "should allow changes to useExperimentalRetryJoin",
+			expectErr: false,
+			before:    beforeUseExperimentalRetryJoin,
+			kcp:       updateUseExperimentalRetryJoin,
+		},
 	}
 
 	for _, tt := range tests {