refactor: wait for load balancer readiness using a private field

This approach is more explicit than looking at the names of the target
groups, and using a private field is simpler.

pkg/model/awsmodel/api_loadbalancer.go

@@ -193,6 +193,12 @@ func (b *APILoadBalancerBuilder) Build(c *fi.CloudupModelBuilderContext) error {
 			Type:              fi.PtrTo("network"),
 		}
 
+		// Wait for all load balancer components to be created (including network interfaces needed for NoneDNS).
+		// Limiting this to clusters using NoneDNS because load balancer creation is quite slow.
+		if b.Cluster.UsesNoneDNS() {
+			nlb.SetWaitForLoadBalancerReady(true)
+		}
+
 		clb = &awstasks.ClassicLoadBalancer{
 			Name:      fi.PtrTo("api." + b.ClusterName()),
 			Lifecycle: b.Lifecycle,

upup/pkg/fi/cloudup/awstasks/network_load_balancer.go

@@ -76,6 +76,13 @@ type NetworkLoadBalancer struct {
 	// WellKnownServices indicates which services are supported by this resource.
 	// This field is internal and is not rendered to the cloud.
 	WellKnownServices []wellknownservices.WellKnownService
+
+	// waitForLoadBalancerReady controls whether we wait for the load balancer to be ready before completing the "Render" operation.
+	waitForLoadBalancerReady bool
+}
+
+func (e *NetworkLoadBalancer) SetWaitForLoadBalancerReady(v bool) {
+	e.waitForLoadBalancerReady = v
 }
 
 var _ fi.CompareWithID = &NetworkLoadBalancer{}
@@ -610,22 +617,17 @@ func (_ *NetworkLoadBalancer) RenderAWS(t *awsup.AWSAPITarget, a, e, changes *Ne
 			e.HostedZoneId = lb.CanonicalHostedZoneId
 			e.VPC = &VPC{ID: lb.VpcId}
 			loadBalancerArn = fi.ValueOf(lb.LoadBalancerArn)
-
 		}
 
-		// Wait for all load balancer components to be created (including network interfaces needed for NoneDNS).
-		// Limiting this to clusters using NoneDNS because load balancer creation is quite slow.
-		for _, tg := range e.TargetGroups {
-			if strings.HasPrefix(fi.ValueOf(tg.Name), "kops-controller") {
-				klog.Infof("Waiting for load balancer %q to be created...", loadBalancerName)
-				request := &elbv2.DescribeLoadBalancersInput{
-					Names: []*string{&loadBalancerName},
-				}
-				err := t.Cloud.ELBV2().WaitUntilLoadBalancerAvailable(request)
-				if err != nil {
-					return fmt.Errorf("error waiting for NLB %q: %w", loadBalancerName, err)
-				}
-				break
+		if e.waitForLoadBalancerReady {
+			klog.Infof("Waiting for load balancer %q to be created...", loadBalancerName)
+			request := &elbv2.DescribeLoadBalancersInput{
+				Names: []*string{&loadBalancerName},
+			}
+
+			err := t.Cloud.ELBV2().WaitUntilLoadBalancerAvailable(request)
+			if err != nil {
+				return fmt.Errorf("error waiting for NLB %q: %w", loadBalancerName, err)
 			}
 		}