createOrUpdatev1.go

func (r *MykindReconciler) CreateOrUpdateReconciler(ctx context.Context, req ctrl.Request, crInstance *grpv1alpha1.Mykind) (ctrl.Result, error) {
	desiredNumPods := crInstance.Spec.NumPods
	actualNumPods := 0

	if crInstance.Status.Pods == nil {
		crInstance.Status.Pods = make(map[string]string)
	} else {
		podList, err = h.getRunningPodsOwnedBy(ctx, crInstance)
		if err != nil {
			return ctrl.Result{}, err
		}
		actualNumPods = len(podList.Items)
	}

	switch {
	case desiredNumPods > actualNumPods:
		for i := 0; i < desiredNumPods; i++ {
			name := fmt.Sprintf("mypod.%s.%d", crInstance.Name, i)
			pod := makePod(name, req.Namespace)
			err := r.AddPodIfNotExist(ctx, req, crInstance, pod)
			if err != nil {
				return ctrl.Result{}, err
			}
		}
	case desiredNumPods < actualNumPods:
		for i := desiredNumPods; i < actualNumPods; i++ {
			name := fmt.Sprintf("mypod.%s.%d", crInstance.Name, i)
			err := r.DeletePodIfExist(ctx, req, crInstance, name)
			if err != nil {
				return ctrl.Result{}, err
			}
		}
	default:
		// nothing to do
		return ctrl.Result{}, nil
	}

	err := r.Status().Update(ctx, crInstance)
	if err != nil {
		log.Error(err, "Error when updating status")
		return ctrl.Result{}, err
	}

	return ctrl.Result{}, nil
}