Add feature gate check for vSphere migration support

Gate vSphere migration functionality behind theClusterAPIMachineManagementVSphere feature gate. The migrationcontrollers for vSphere will now only start when both the generalMachineAPIMigration feature gate and the vSphere-specificClusterAPIMachineManagementVSphere feature gate are enabled.

Author: AnnaZivkovic

cmd/machine-api-migration/main.go

@@ -94,7 +94,7 @@ func main() {
 	}
 
 	ctx := ctrl.SetupSignalHandler()
-	checkFeatureGates(ctx, mgr)
+	featureGateAccessor := checkFeatureGates(ctx, mgr)
 
 	infra, err := util.GetInfra(ctx, mgr.GetAPIReader())
 	if err != nil {
@@ -113,7 +113,7 @@ func main() {
 		os.Exit(1)
 	}
 
-	checkPlatformSupported(ctx, platform)
+	checkPlatformSupported(ctx, platform, featureGateAccessor)
 
 	for name, controller := range getControllers(opts, platform, infra, infraTypes) {
 		if err := controller.SetupWithManager(mgr); err != nil {
@@ -130,7 +130,7 @@ func main() {
 	}
 }
 
-func checkFeatureGates(ctx context.Context, mgr ctrl.Manager) {
+func checkFeatureGates(ctx context.Context, mgr ctrl.Manager) featuregates.FeatureGateAccess {
 	featureGateAccessor, err := getFeatureGates(ctx, mgr)
 	if err != nil {
 		klog.Error(err, "unable to get feature gates")
@@ -147,13 +147,27 @@ func checkFeatureGates(ctx context.Context, mgr ctrl.Manager) {
 		klog.Info("MachineAPIMigration feature gate is not enabled, nothing to do. Waiting for termination signal.")
 		exitAfterTerminationSignal(ctx)
 	}
+
+	return featureGateAccessor
 }
 
-func checkPlatformSupported(ctx context.Context, platform configv1.PlatformType) {
+func checkPlatformSupported(ctx context.Context, platform configv1.PlatformType, featureGateAccessor featuregates.FeatureGateAccess) {
 	switch platform {
-	case configv1.AWSPlatformType, configv1.OpenStackPlatformType, configv1.VSpherePlatformType:
+	case configv1.AWSPlatformType, configv1.OpenStackPlatformType:
 		klog.Infof("MachineAPIMigration: starting %s controllers", platform)
+	case configv1.VSpherePlatformType:
+		currentFeatureGates, err := featureGateAccessor.CurrentFeatureGates()
+		if err != nil {
+			klog.Error(err, "unable to get current feature gates")
+			os.Exit(1)
+		}
 
+		if !currentFeatureGates.Enabled(features.FeatureGateClusterAPIMachineManagementVSphere) {
+			klog.Info("ClusterAPIMachineManagementVSphere feature gate is not enabled for vSphere platform. Waiting for termination signal.")
+			exitAfterTerminationSignal(ctx)
+		}
+
+		klog.Infof("MachineAPIMigration: starting %s controllers", platform)
 	default:
 		klog.Infof("MachineAPIMigration not implemented for platform %s, nothing to do. Waiting for termination signal.", platform)
 		exitAfterTerminationSignal(ctx)