Function ExampleNewUnmanaged

pkg/controller/example_test.go:127–165

This example creates a new controller named "pod-controller" to watch Pods and call a no-op reconciler. The controller is not added to the provided manager, and must thus be started and stopped by the caller.

()

// and call a no-op reconciler. The controller is not added to the provided
// manager, and must thus be started and stopped by the caller.
func ExampleNewUnmanaged() {
	// mgr is a manager.Manager

	// Configure creates a new controller but does not add it to the supplied
	// manager.
	c, err := controller.NewUnmanaged("pod-controller", controller.Options{
		Reconciler: reconcile.Func(func(context.Context, reconcile.Request) (reconcile.Result, error) {
			return reconcile.Result{}, nil
		}),
	})
	if err != nil {
		log.Error(err, "unable to create pod-controller")
		os.Exit(1)
	}

	if err := c.Watch(source.Kind(mgr.GetCache(), &corev1.Pod{}, &handler.TypedEnqueueRequestForObject[*corev1.Pod]{})); err != nil {
		log.Error(err, "unable to watch pods")
		os.Exit(1)
	}

	ctx, cancel := context.WithCancel(context.Background())

	// Start our controller in a goroutine so that we do not block.
	go func() {
		// Block until our controller manager is elected leader. We presume our
		// entire process will terminate if we lose leadership, so we don't need
		// to handle that.
		<-mgr.Elected()

		// Start our controller. This will block until the context is
		// closed, or the controller returns an error.
		if err := c.Start(ctx); err != nil {
			log.Error(err, "cannot run experiment controller")
		}
	}()

	// Stop our controller.
	cancel()
}