Refactor .loadBalancer properties to use getter pattern

aws · Feb 12, 2020 · 57cd88a · 57cd88a
1 parent 9ba9d5c
commit 57cd88a
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Showing 6 changed files with 38 additions and 16 deletions.
diff --git a/packages/@aws-cdk/aws-ecs-patterns/lib/base/application-load-balanced-service-base.ts b/packages/@aws-cdk/aws-ecs-patterns/lib/base/application-load-balanced-service-base.ts
@@ -255,7 +255,12 @@ export abstract class ApplicationLoadBalancedServiceBase extends cdk.Construct {
   /**
    * The Application Load Balancer for the service.
    */
-  public readonly loadBalancer: ApplicationLoadBalancer;
+  public get loadBalancer(): ApplicationLoadBalancer {
+    if (!this._applicationLoadBalancer) {
+      throw new Error('.loadBalancer can only be accessed if the class was constructed with an owned, not imported, load balancer');
+    }
+    return this._applicationLoadBalancer;
+  }
 
   /**
    * The listener for the service.
@@ -277,6 +282,8 @@ export abstract class ApplicationLoadBalancedServiceBase extends cdk.Construct {
    */
   public readonly cluster: ICluster;
 
+  private readonly _applicationLoadBalancer?: ApplicationLoadBalancer;
+
   /**
    * Constructs a new instance of the ApplicationLoadBalancedServiceBase class.
    */
@@ -300,20 +307,20 @@ export abstract class ApplicationLoadBalancedServiceBase extends cdk.Construct {
       internetFacing
     };
 
-    this.loadBalancer = props.loadBalancer !== undefined ? props.loadBalancer as ApplicationLoadBalancer
+    const loadBalancer = props.loadBalancer !== undefined ? props.loadBalancer
                         : new ApplicationLoadBalancer(this, 'LB', lbProps);
 
     if (props.certificate !== undefined && props.protocol !== undefined && props.protocol !== ApplicationProtocol.HTTPS) {
       throw new Error('The HTTPS protocol must be used when a certificate is given');
     }
     const protocol = props.protocol !== undefined ? props.protocol :
-    (props.certificate ? ApplicationProtocol.HTTPS : ApplicationProtocol.HTTP);
+      (props.certificate ? ApplicationProtocol.HTTPS : ApplicationProtocol.HTTP);
 
     const targetProps = {
       port: 80
     };
 
-    this.listener = this.loadBalancer.addListener('PublicListener', {
+    this.listener = loadBalancer.addListener('PublicListener', {
       protocol,
       port: props.listenerPort,
       open: true
@@ -338,7 +345,7 @@ export abstract class ApplicationLoadBalancedServiceBase extends cdk.Construct {
       this.listener.addCertificates('Arns', [ListenerCertificate.fromCertificateManager(this.certificate)]);
     }
 
-    let domainName = this.loadBalancer.loadBalancerDnsName;
+    let domainName = loadBalancer.loadBalancerDnsName;
     if (typeof props.domainName !== 'undefined') {
       if (typeof props.domainZone === 'undefined') {
         throw new Error('A Route53 hosted domain zone name is required to configure the specified domain name');
@@ -347,13 +354,17 @@ export abstract class ApplicationLoadBalancedServiceBase extends cdk.Construct {
       const record = new ARecord(this, "DNS", {
         zone: props.domainZone,
         recordName: props.domainName,
-        target: RecordTarget.fromAlias(new LoadBalancerTarget(this.loadBalancer)),
+        target: RecordTarget.fromAlias(new LoadBalancerTarget(loadBalancer)),
       });
 
       domainName = record.domainName;
     }
 
-    new cdk.CfnOutput(this, 'LoadBalancerDNS', { value: this.loadBalancer.loadBalancerDnsName });
+    if (loadBalancer instanceof ApplicationLoadBalancer) {
+      this._applicationLoadBalancer = loadBalancer;
+    }
+
+    new cdk.CfnOutput(this, 'LoadBalancerDNS', { value: loadBalancer.loadBalancerDnsName });
     new cdk.CfnOutput(this, 'ServiceURL', { value: protocol.toLowerCase() + '://' + domainName });
   }
 

diff --git a/packages/@aws-cdk/aws-ecs-patterns/lib/base/network-load-balanced-service-base.ts b/packages/@aws-cdk/aws-ecs-patterns/lib/base/network-load-balanced-service-base.ts
@@ -230,7 +230,12 @@ export abstract class NetworkLoadBalancedServiceBase extends cdk.Construct {
   /**
    * The Network Load Balancer for the service.
    */
-  public readonly loadBalancer: NetworkLoadBalancer;
+  public get loadBalancer(): NetworkLoadBalancer {
+    if (!this._networkLoadBalancer) {
+      throw new Error(".loadBalancer can only be accessed if the class was constructed with an owned, not imported, load balancer");
+    }
+    return this._networkLoadBalancer;
+  }
 
   /**
    * The listener for the service.
@@ -247,6 +252,7 @@ export abstract class NetworkLoadBalancedServiceBase extends cdk.Construct {
    */
   public readonly cluster: ICluster;
 
+  private readonly _networkLoadBalancer?: NetworkLoadBalancer;
   /**
    * Constructs a new instance of the NetworkLoadBalancedServiceBase class.
    */
@@ -270,15 +276,16 @@ export abstract class NetworkLoadBalancedServiceBase extends cdk.Construct {
       internetFacing
     };
 
-    this.loadBalancer = props.loadBalancer !== undefined ? props.loadBalancer as NetworkLoadBalancer : new NetworkLoadBalancer(this, 'LB', lbProps);
+    const loadBalancer = props.loadBalancer !== undefined ? props.loadBalancer :
+      new NetworkLoadBalancer(this, 'LB', lbProps);
 
     const listenerPort = props.listenerPort !== undefined ? props.listenerPort : 80;
 
     const targetProps = {
       port: 80
     };
 
-    this.listener = this.loadBalancer.addListener('PublicListener', { port: listenerPort });
+    this.listener = loadBalancer.addListener('PublicListener', { port: listenerPort });
     this.targetGroup = this.listener.addTargets('ECS', targetProps);
 
     if (typeof props.domainName !== 'undefined') {
@@ -289,10 +296,14 @@ export abstract class NetworkLoadBalancedServiceBase extends cdk.Construct {
       new ARecord(this, "DNS", {
         zone: props.domainZone,
         recordName: props.domainName,
-        target: RecordTarget.fromAlias(new LoadBalancerTarget(this.loadBalancer)),
+        target: RecordTarget.fromAlias(new LoadBalancerTarget(loadBalancer)),
       });
     }
 
+    if (loadBalancer instanceof NetworkLoadBalancer) {
+      this._networkLoadBalancer = loadBalancer;
+    }
+
     if (props.loadBalancer === undefined) {
       new cdk.CfnOutput(this, 'LoadBalancerDNS', { value: this.loadBalancer.loadBalancerDnsName });
     }

diff --git a/packages/@aws-cdk/aws-ecs-patterns/test/ec2/test.l3s.ts b/packages/@aws-cdk/aws-ecs-patterns/test/ec2/test.l3s.ts
@@ -941,7 +941,7 @@ export = {
      cluster.addCapacity("Capacity", {instanceType: new ec2.InstanceType('t2.micro')});
      const nlb  = NetworkLoadBalancer.fromNetworkLoadBalancerAttributes(stack, "NLB", {
        loadBalancerArn: nlbArn,
-       loadBalancerVpc: vpc,
+       vpc,
      });
      const taskDef = new ecs.Ec2TaskDefinition(stack, 'TaskDef');
      const container = taskDef.addContainer('Container', {

diff --git a/packages/@aws-cdk/aws-ecs-patterns/test/fargate/test.load-balanced-fargate-service.ts b/packages/@aws-cdk/aws-ecs-patterns/test/fargate/test.load-balanced-fargate-service.ts
@@ -511,7 +511,7 @@ export = {
     // WHEN
     const nlb2 = NetworkLoadBalancer.fromNetworkLoadBalancerAttributes(stack2, "ImportedNLB", {
       loadBalancerArn: nlbArn,
-      loadBalancerVpc: vpc1,
+      vpc: vpc1,
     });
     const taskDef = new ecs.FargateTaskDefinition(stack2, 'TaskDef', {
       cpu: 1024,

diff --git a/packages/@aws-cdk/aws-elasticloadbalancingv2/lib/nlb/network-load-balancer.ts b/packages/@aws-cdk/aws-elasticloadbalancingv2/lib/nlb/network-load-balancer.ts
@@ -45,7 +45,7 @@ export interface NetworkLoadBalancerAttributes {
    * @default - When not provided, listeners cannot be created on imported load
    * balancers.
    */
-  readonly loadBalancerVpc?: ec2.IVpc;
+  readonly vpc?: ec2.IVpc;
 }
 
 /**
@@ -57,7 +57,7 @@ export class NetworkLoadBalancer extends BaseLoadBalancer implements INetworkLoa
   public static fromNetworkLoadBalancerAttributes(scope: Construct, id: string, attrs: NetworkLoadBalancerAttributes): INetworkLoadBalancer {
     class Import extends Resource implements INetworkLoadBalancer {
       public readonly loadBalancerArn = attrs.loadBalancerArn;
-      public readonly vpc?: ec2.IVpc = attrs.loadBalancerVpc;
+      public readonly vpc?: ec2.IVpc = attrs.vpc;
       public addListener(lid: string, props: BaseNetworkListenerProps): NetworkListener {
         return new NetworkListener(this, lid, {
           loadBalancer: this,

diff --git a/packages/@aws-cdk/aws-elasticloadbalancingv2/test/nlb/test.load-balancer.ts b/packages/@aws-cdk/aws-elasticloadbalancingv2/test/nlb/test.load-balancer.ts
@@ -216,7 +216,7 @@ export = {
     const nlbArn = "arn:aws:elasticloadbalancing::000000000000::dummyloadbalancer";
     const nlb = elbv2.NetworkLoadBalancer.fromNetworkLoadBalancerAttributes(stack, 'NLB', {
       loadBalancerArn: nlbArn,
-      loadBalancerVpc: vpc,
+      vpc,
     });
     // WHEN
     const listener = nlb.addListener('Listener', {port: 80});