func()

in controllers/service/controller.go [369:439]

• 50 lines of code
• 13 McCabe index (conditional complexity)

func (s *Controller) syncLoadBalancerIfNeeded(ctx context.Context, service *v1.Service, key string) (loadBalancerOperation, error) {
	// Note: It is safe to just call EnsureLoadBalancer.  But, on some clouds that requires a delete & create,
	// which may involve service interruption.  Also, we would like user-friendly events.

	// Save the state so we can avoid a write if it doesn't change
	previousStatus := service.Status.LoadBalancer.DeepCopy()
	var newStatus *v1.LoadBalancerStatus
	var op loadBalancerOperation
	var err error

	if !wantsLoadBalancer(service) || needsCleanup(service) {
		// Delete the load balancer if service no longer wants one, or if service needs cleanup.
		op = deleteLoadBalancer
		newStatus = &v1.LoadBalancerStatus{}
		_, exists, err := s.balancer.GetLoadBalancer(ctx, s.clusterName, service)
		if err != nil {
			return op, fmt.Errorf("failed to check if load balancer exists before cleanup: %v", err)
		}
		if exists {
			klog.V(2).Infof("Deleting existing load balancer for service %s", key)
			s.eventRecorder.Event(service, v1.EventTypeNormal, "DeletingLoadBalancer", "Deleting load balancer")
			if err := s.balancer.EnsureLoadBalancerDeleted(ctx, s.clusterName, service); err != nil {
				return op, fmt.Errorf("failed to delete load balancer: %v", err)
			}
		}
		// Always remove finalizer when load balancer is deleted, this ensures Services
		// can be deleted after all corresponding load balancer resources are deleted.
		if err := s.removeFinalizer(service); err != nil {
			return op, fmt.Errorf("failed to remove load balancer cleanup finalizer: %v", err)
		}
		s.eventRecorder.Event(service, v1.EventTypeNormal, "DeletedLoadBalancer", "Deleted load balancer")
	} else {
		// Create or update the load balancer if service wants one.
		op = ensureLoadBalancer
		klog.V(2).Infof("Ensuring load balancer for service %s", key)
		s.eventRecorder.Event(service, v1.EventTypeNormal, "EnsuringLoadBalancer", "Ensuring load balancer")
		// Always add a finalizer prior to creating load balancers, this ensures Services
		// can't be deleted until all corresponding load balancer resources are also deleted.
		if err := s.addFinalizer(service); err != nil {
			return op, fmt.Errorf("failed to add load balancer cleanup finalizer: %v", err)
		}
		newStatus, err = s.ensureLoadBalancer(ctx, service)
		if err != nil {
			if err == cloudprovider.ImplementedElsewhere {
				// ImplementedElsewhere indicates that the ensureLoadBalancer is a nop and the
				// functionality is implemented by a different controller.  In this case, we
				// return immediately without doing anything.
				klog.V(4).Infof("LoadBalancer for service %s implemented by a different controller %s, Ignoring error", key, s.cloud.ProviderName())
				return op, nil
			}
			return op, fmt.Errorf("failed to ensure load balancer: %v", err)
		}
		if newStatus == nil {
			return op, fmt.Errorf("service status returned by EnsureLoadBalancer is nil")
		}

		s.eventRecorder.Event(service, v1.EventTypeNormal, "EnsuredLoadBalancer", "Ensured load balancer")
	}

	if err := s.patchStatus(service, previousStatus, newStatus); err != nil {
		// Only retry error that isn't not found:
		// - Not found error mostly happens when service disappears right after
		//   we remove the finalizer.
		// - We can't patch status on non-exist service anyway.
		if !errors.IsNotFound(err) {
			return op, fmt.Errorf("failed to update load balancer status: %v", err)
		}
	}

	return op, nil
}