feat(autoscaling): Support AssociatePublicIpAddress (#1604)

Allow AssociatePublicIpAddress property to be specified in ASG Launch
Configuration.

Fixes #1603

Author: otterley

packages/@aws-cdk/assert/lib/assertions/have-resource.ts

@@ -103,7 +103,7 @@ function makeSuperObjectPredicate(obj: any, allowValueExtension: boolean) {
   };
 }
 
-interface InspectionFailure {
+export interface InspectionFailure {
   resource: any;
   failureReason: string;
 }

packages/@aws-cdk/aws-autoscaling/lib/auto-scaling-group.ts

@@ -148,6 +148,14 @@ export interface AutoScalingGroupProps {
    * @default 300 (5 minutes)
    */
   cooldownSeconds?: number;
+
+  /**
+   * Whether instances in the Auto Scaling Group should have public
+   * IP addresses associated with them.
+   *
+   * @default Use subnet setting
+   */
+  associatePublicIpAddress?: boolean;
 }
 
 /**
@@ -231,7 +239,8 @@ export class AutoScalingGroup extends cdk.Construct implements IAutoScalingGroup
       instanceType: props.instanceType.toString(),
       securityGroups: securityGroupsToken,
       iamInstanceProfile: iamProfile.ref,
-      userData: userDataToken
+      userData: userDataToken,
+      associatePublicIpAddress: props.associatePublicIpAddress,
     });
 
     launchConfig.addDependency(this.role);
@@ -748,4 +757,4 @@ export interface MetricTargetTrackingProps extends BaseTargetTrackingProps {
    * Value to keep the metric around
    */
   targetValue: number;
-}
+}

packages/@aws-cdk/aws-autoscaling/test/test.auto-scaling-group.ts

@@ -1,4 +1,4 @@
-import { expect, haveResource, haveResourceLike, ResourcePart } from '@aws-cdk/assert';
+import { expect, haveResource, haveResourceLike, InspectionFailure, ResourcePart } from '@aws-cdk/assert';
 import ec2 = require('@aws-cdk/aws-ec2');
 import iam = require('@aws-cdk/aws-iam');
 import cdk = require('@aws-cdk/cdk');
@@ -404,6 +404,79 @@ export = {
     }));
     test.done();
   },
+  'allows association of public IP address'(test: Test) {
+    // GIVEN
+    const stack = new cdk.Stack();
+    const vpc = mockVpc(stack);
+
+    // WHEN
+    new autoscaling.AutoScalingGroup(stack, 'MyStack', {
+      instanceType: new ec2.InstanceTypePair(ec2.InstanceClass.M4, ec2.InstanceSize.Micro),
+      machineImage: new ec2.AmazonLinuxImage(),
+      vpc,
+      minSize: 0,
+      maxSize: 0,
+      desiredCapacity: 0,
+      associatePublicIpAddress: true,
+    });
+
+    // THEN
+    expect(stack).to(haveResource("AWS::AutoScaling::LaunchConfiguration", {
+        AssociatePublicIpAddress: true,
+      }
+    ));
+    test.done();
+  },
+  'allows disassociation of public IP address'(test: Test) {
+    // GIVEN
+    const stack = new cdk.Stack();
+    const vpc = mockVpc(stack);
+
+    // WHEN
+    new autoscaling.AutoScalingGroup(stack, 'MyStack', {
+      instanceType: new ec2.InstanceTypePair(ec2.InstanceClass.M4, ec2.InstanceSize.Micro),
+      machineImage: new ec2.AmazonLinuxImage(),
+      vpc,
+      minSize: 0,
+      maxSize: 0,
+      desiredCapacity: 0,
+      associatePublicIpAddress: false,
+    });
+
+    // THEN
+    expect(stack).to(haveResource("AWS::AutoScaling::LaunchConfiguration", {
+        AssociatePublicIpAddress: false,
+      }
+    ));
+    test.done();
+  },
+  'does not specify public IP address association by default'(test: Test) {
+    // GIVEN
+    const stack = new cdk.Stack();
+    const vpc = mockVpc(stack);
+
+    // WHEN
+    new autoscaling.AutoScalingGroup(stack, 'MyStack', {
+      instanceType: new ec2.InstanceTypePair(ec2.InstanceClass.M4, ec2.InstanceSize.Micro),
+      machineImage: new ec2.AmazonLinuxImage(),
+      vpc,
+      minSize: 0,
+      maxSize: 0,
+      desiredCapacity: 0,
+    });
+
+    // THEN
+    expect(stack).to(haveResource("AWS::AutoScaling::LaunchConfiguration", (resource: any, errors: InspectionFailure) => {
+      for (const key of Object.keys(resource)) {
+        if (key === "AssociatePublicIpAddress") {
+          errors.failureReason = "Has AssociatePublicIpAddress";
+          return false;
+        }
+      }
+      return true;
+    }));
+    test.done();
+  },
 };
 
 function mockVpc(stack: cdk.Stack) {