AWS CDK VPC Peering and Routing

vpc-peering.ts

    private _createVpcPeering() {
        // Currently, the console shows a name attribute for the peering connection but no
        // name is available in the peering connection properties.
        this.vpcPeeringConnection = new CfnVPCPeeringConnection(this, 'PeerToLegacyVpc', {
                vpcId: this.vpc.vpcId,
                peerVpcId: this.legacyVpc.vpcId,
            }
        );
    }

    private _createPeeringRoutes() {
        // Create routes from legacy subnets to new VPC CIDR
        const legacySubnets = this.legacyVpc.privateSubnets.concat(this.legacyVpc.publicSubnets);
        let processed = [] as string[];
        let i=1;
        legacySubnets.forEach((subnetRef) => {
            const routeTableId = subnetRef.routeTable.routeTableId;
            if (!processed.includes(routeTableId)) {
                processed.push(routeTableId);
                this.legacyVpcToNewVpcRoutes.push(new CfnRoute(this, `RouteToNewVpc${i++}`, {
                    routeTableId,
                    vpcPeeringConnectionId: this.vpcPeeringConnection.ref,
                    destinationCidrBlock: this.vpc.vpcCidrBlock,
                }));
            }
        });
        // Create routes from new VPC to legacy VPC CIDR
        const newSubnets = this.vpc.publicSubnets.concat(this.vpc.privateSubnets);
        processed = [];
        i=1;
        newSubnets.forEach((subnetRef) => {
            const routeTableId = subnetRef.routeTable.routeTableId;
            if (!processed.includes(routeTableId)) {
                processed.push(routeTableId);
                this.vpcToLegacyVpcRoutes.push(new CfnRoute(this, `RouteToLegacyVpc${i++}`, {
                    routeTableId,
                    vpcPeeringConnectionId: this.vpcPeeringConnection.ref,
                    destinationCidrBlock: this.legacyVpc.vpcCidrBlock,
                }));
            }
        });
    }