Add conflicts with, node_version only works on the default node pool (#…

…4762)

* Add conflicts with, node_version only works on the default node pool

* Use customizediff rather than conflicts with

mmv1/third_party/terraform/resources/resource_container_cluster.go.erb

@@ -131,6 +131,7 @@ func resourceContainerCluster() *schema.Resource {
 			customdiff.ForceNewIfChange("enable_l4_ilb_subsetting", isBeenEnabled),
 			<% end -%>
 			containerClusterAutopilotCustomizeDiff,
+			containerClusterNodeVersionRemoveDefaultCustomizeDiff,
 		),
 
 		Timeouts: &schema.ResourceTimeout{
@@ -4077,6 +4078,14 @@ func containerClusterAutopilotCustomizeDiff(_ context.Context, d *schema.Resourc
 	return nil
 }
 
+// node_version only applies to the default node pool, so it should conflict with remove_default_node_pool = true
+func containerClusterNodeVersionRemoveDefaultCustomizeDiff(_ context.Context, d *schema.ResourceDiff, meta interface{}) error {
+	if d.Get("node_version").(string) != "" && d.Get("remove_default_node_pool").(bool) {
+		return fmt.Errorf("node_version can only be specified if remove_default_node_pool is not true")
+	}
+	return nil
+}
+
 <% unless version == 'ga' -%>
 func podSecurityPolicyCfgSuppress(k, old, new string, r *schema.ResourceData) bool {
 	if k == "pod_security_policy_config.#" && old == "1" && new == "0" {