Make garbage collection configurable

This PR allows to configure garbage collection and define what clean-up
tasks to execute during cluster deprovisioning.

Author: Fedosin

exp/api/v1beta2/types.go

@@ -26,6 +26,10 @@ const (
 	// ExternalResourceGCAnnotation is the name of an annotation that indicates if
 	// external resources should be garbage collected for the cluster.
 	ExternalResourceGCAnnotation = "aws.cluster.x-k8s.io/external-resource-gc"
+
+	// ExternalResourceGCTasksAnnotation is the name of an annotation that indicates what
+	// external resources tasks should be executed by garbage collector for the cluster.
+	ExternalResourceGCTasksAnnotation = "aws.cluster.x-k8s.io/external-resource-tasks-gc"
 )
 
 // EBS can be used to automatically set up EBS volumes when an instance is launched.

pkg/cloud/services/gc/cleanup.go

@@ -69,7 +69,27 @@ func (s *Service) deleteResources(ctx context.Context) error {
 		return fmt.Errorf("collecting resources: %w", err)
 	}
 
-	if deleteErr := s.cleanupFuncs.Execute(ctx, resources); deleteErr != nil {
+	cleanupFuncs := s.cleanupFuncs
+
+	if val, found := annotations.Get(s.scope.InfraCluster(), expinfrav1.ExternalResourceGCTasksAnnotation); found {
+		var gcTaskToFunc = map[string]ResourceCleanupFunc{
+			"load-balancer":  s.deleteLoadBalancers,
+			"target-group":   s.deleteTargetGroups,
+			"security-group": s.deleteSecurityGroups,
+		}
+
+		cleanupFuncs = ResourceCleanupFuncs{}
+
+		tasks := strings.Split(val, ",")
+
+		// TODO: add some validation here.
+
+		for _, task := range tasks {
+			cleanupFuncs = append(cleanupFuncs, gcTaskToFunc[task])
+		}
+	}
+
+	if deleteErr := cleanupFuncs.Execute(ctx, resources); deleteErr != nil {
 		return fmt.Errorf("deleting resources: %w", deleteErr)
 	}