include · July 9, 2020 00:36 · Aug 19, 2018
diff --git a/index.ts b/index.ts
@@ -0,0 +1,147 @@
+/*
+I was curious as to whether it was possible to make resources
+created using CDK constructs work with raw CloudFormation
+resources and vice versa.
+
+This aws-cdk app demonstrates a VPC and an ELB that belongs to it
+in different, dependant stacks, leveraging CFN outputs / imports,
+and leveraging CDK's method of passing information from one
+stack to another.
+*/
+
+import cdk = require("@aws-cdk/cdk");
+import ec2 = require("@aws-cdk/aws-ec2");
+import elb = require("@aws-cdk/aws-elasticloadbalancing");
+
+interface ElbProps {
+  vpc: ec2.VpcNetworkRefProps;
+}
+
+// A VPC made using CDK constructs
+class VpcDemoStack extends cdk.Stack {
+  public readonly vpcRef: ec2.VpcNetworkRefProps;
+
+  constructor(parent: cdk.App, id: string, props?: cdk.StackProps) {
+    super(parent, id, props);
+    const vpc = new ec2.VpcNetwork(this, "DemoVPC");
+
+    this.vpcRef = vpc.export();
+  }
+}
+
+// A VPC made using Cloudformation primitives - much simpler than
+// what the CDK construct would produce, but enough for a demonstration.
+class VpcCFNDemoStack extends cdk.Stack {
+  public readonly vpcRef: ec2.VpcNetworkRefProps;
+
+  constructor(parent: cdk.App, id: string, props?: cdk.StackProps) {
+    super(parent, id, props);
+    const vpc = new ec2.cloudformation.VPCResource(this, "DemoCFNVPC", {
+      cidrBlock: "10.0.0.0/16"
+    });
+    const publicSubnet = new ec2.cloudformation.SubnetResource(
+      this,
+      "DemoCFNSubnet1",
+      {
+        cidrBlock: "10.0.54.0/24",
+        availabilityZone: "us-east-1a",
+        vpcId: vpc.ref
+      }
+    );
+
+    const privateSubnet = new ec2.cloudformation.SubnetResource(
+      this,
+      "DemoCFNSubnet2",
+      {
+        cidrBlock: "10.0.55.0/24",
+        availabilityZone: "us-east-1a",
+        vpcId: vpc.ref
+      }
+    );
+
+    // This is the exact same data type as what our CDK-based
+    // VPC is exporting - we're just populating it manually!
+    const vpcProps = {
+      vpcId: vpc.ref,
+      availabilityZones: ["us-east-1a"],
+      publicSubnetIds: [publicSubnet.ref],
+      privateSubnetIds: [privateSubnet.ref]
+    };
+    this.vpcRef = ec2.VpcNetworkRef.import(
+      this,
+      "ExternalVPC",
+      vpcProps
+    ).export();
+  }
+}
+
+// A Load Balancer made using a CDK construct
+class ElbDemoStack extends cdk.Stack {
+  constructor(parent: cdk.App, id: string, props: ElbProps) {
+    super(parent, id);
+
+    const vpc = ec2.VpcNetworkRef.import(this, "ExternalVPC", props.vpc);
+
+    new ec2.ClassicLoadBalancer(this, "DemoELB", {
+      vpc,
+      listeners: [{ externalPort: 80 }]
+    });
+  }
+}
+
+// A Load Balancer made using Cloudformation primitives
+class ElbCFNDemoStack extends cdk.Stack {
+  constructor(parent: cdk.App, id: string, props: ElbProps) {
+    super(parent, id);
+
+    const vpc = ec2.VpcNetworkRef.import(this, "ExternalVPC", props.vpc);
+
+    new elb.cloudformation.LoadBalancerResource(this, "DemoELBCFN", {
+      subnets: vpc.privateSubnets.map(s => s.subnetId),
+      scheme: "internal",
+      listeners: [
+        {
+          loadBalancerPort: "80",
+          protocol: "HTTP",
+          instancePort: "80",
+          instanceProtocol: "HTTP"
+        }
+      ]
+    });
+  }
+}
+
+class MyApp extends cdk.App {
+  constructor(argv: string[]) {
+    super(argv);
+
+    const cdkVpcStack = new VpcDemoStack(this, "vpc-demo");
+
+    const cloudformationVpcStack = new VpcCFNDemoStack(this, "vpc-cfn-demo");
+
+    /* 
+    Demonstrate creating a VPC using a CDK construct and then using it
+    with a CFK construct load balancer and a CloudFormation primitive
+    load balancer
+    */
+    new ElbDemoStack(this, "cdk-vpc-to-cdk-elb-demo", {
+      vpc: cdkVpcStack.vpcRef
+    });
+    new ElbCFNDemoStack(this, "cdk-vpc-to-cfn-elb-demo", {
+      vpc: cdkVpcStack.vpcRef
+    });
+
+    /*
+    Demonstrate creating a VPC using Cloudformation primitives and then
+    using it with a CDK construct and a Cloudformation primitive respectively
+    */
+    new ElbDemoStack(this, "cfn-vpc-to-cdk-elb-demo", {
+      vpc: cloudformationVpcStack.vpcRef
+    });
+    new ElbCFNDemoStack(this, "cfn-vpc-to-cfn-elb-demo", {
+      vpc: cloudformationVpcStack.vpcRef
+    });
+  }
+}
+
+process.stdout.write(new MyApp(process.argv).run());