Add Ipv6 to existing CDK VPC Using IPAM Pools

gistfile1.txt

import * as core from 'aws-cdk-lib';
import {
  aws_ec2 as ec2,
} from 'aws-cdk-lib';

import * as constructs from 'constructs';

export interface AddIpv6ToExisitingVpcProps extends ec2.VpcProps {
  ipv6IpamPoolId: string;
  ipv6IpamScopeId: string;
  vpc: ec2.Vpc
  vpcCidrMask?: number | undefined
}

export class AddIpv6ToExisitingVpcWithIPAM extends ec2.Vpc {

  public egressOnlyInternetGatewayId?: string;

  constructor(scope: constructs.Construct, id: string, props: AddIpv6ToExisitingVpcProps) {
    super(scope, id, props);

    // allocate a cidr from the ipam pool
    const ipv6Cidr = new ec2.CfnVPCCidrBlock(this, 'Ipv6Cidr', {
      vpcId: props.vpc.vpcId,
      ipv6IpamPoolId: props.ipv6IpamPoolId,
      ipv6NetmaskLength: props.vpcCidrMask ?? 56,
    });
  
    // create a vpc Pool to allocate IPv6 Cidrs for Subnets
    const pool = new ec2.CfnIPAMPool(this, 'VpcPool', {
      awsService: 'ec2',
      ipamScopeId: props.ipv6IpamScopeId,
      locale:  core.Aws.REGION,
      publicIpSource: 'amazon',
      sourceResource: {
        resourceId: props.vpc.vpcId,
        resourceOwner: core.Aws.ACCOUNT_ID,
        resourceRegion: core.Aws.REGION,
        resourceType: 'vpc',
      },
      addressFamily: 'ipv6',
      autoImport: true,
      sourceIpamPoolId: props.ipv6IpamPoolId,
    });

    const provisioning = new ec2.CfnIPAMPoolCidr(this, `poolcidr`, {
      ipamPoolId: pool.attrIpamPoolId,
      cidr: core.Fn.select(0, props.vpc.vpcIpv6CidrBlocks)
    });

    provisioning.node.addDependency(ipv6Cidr);

    // provision IP address's.
    [
      ...props.vpc.publicSubnets,
      ...props.vpc.privateSubnets,
      ...props.vpc.isolatedSubnets,
    ].forEach((subnet) => {
        subnet.node.addDependency(provisioning);
        new ec2.CfnSubnetCidrBlock(this, `${subnet.node.addr}-cidr`, {
          ipv6IpamPoolId: pool.attrIpamPoolId,
          subnetId: subnet.subnetId,
          ipv6NetmaskLength: 64,
        })
    });
   
    // add a EgressOnlyGateway to the vpc
    const egressOnlyIgw = new ec2.CfnEgressOnlyInternetGateway(this, 'EgressOnlyIGW', {
      vpcId: props.vpc.vpcId,
    });

    // add a default route to the egress only gateway fpr all private subnets
    props.vpc.privateSubnets.forEach((subnet) => {
      new ec2.CfnRoute(this, `DefaultRoute-${subnet.node.addr}`, {
        routeTableId: subnet.routeTable.routeTableId,
        destinationIpv6CidrBlock: '::/0',
        egressOnlyInternetGatewayId: egressOnlyIgw.ref,
      });
    });

    // add a default route to the internet gateway for all public subnets
    props.vpc.publicSubnets.forEach((subnet) => {
      new ec2.CfnRoute(this, `DefaultRoute-${subnet.node.addr}`, {
        routeTableId: subnet.routeTable.routeTableId,
        destinationIpv6CidrBlock: '::/0',
        gatewayId: props.vpc.internetGatewayId
      });
    });
  }
};