How to Create a VPC With One Public and Two Private Subnets?

Introduction

In this solution, we will create a Virtual Private Cloud (VPC) with one public subnet and two private subnets using Pulumi in TypeScript. A VPC is a virtual network dedicated to your AWS account, allowing you to launch AWS resources in a logically isolated section of the AWS cloud. The key services involved in this solution are AWS VPC, Subnets, and Internet Gateway.

Step-by-Step Explanation

Step 1: Create a New Pulumi Project

First, create a new Pulumi project using the Pulumi CLI. This will set up the necessary files and directories for your Pulumi program.

Step 2: Install AWS Pulumi Package

Install the AWS Pulumi package to interact with AWS resources. You can do this by running npm install @pulumi/aws.

Step 3: Import Required Modules

In your Pulumi program, import the required modules from the Pulumi and AWS Pulumi packages.

Step 4: Create a VPC

Create a new VPC resource with the desired CIDR block.

Step 5: Create Subnets

Create one public subnet and two private subnets within the VPC. Specify the CIDR blocks for each subnet.

Step 6: Create an Internet Gateway

Create an Internet Gateway and attach it to the VPC. This will allow the public subnet to communicate with the internet.

Step 7: Create Route Tables

Create a route table for the public subnet and associate it with the Internet Gateway. Also, create route tables for the private subnets.

Step 8: Associate Subnets with Route Tables

Associate the public subnet with the public route table and the private subnets with their respective route tables.

Key Points

• A VPC is a virtual network dedicated to your AWS account.
• Subnets are subdivisions of a VPC’s IP address range that allow you to group resources based on security and operational needs.
• An Internet Gateway allows communication between the VPC and the internet.
• Route tables control the routing of traffic within the VPC.

Conclusion

By following these steps, you can create a VPC with one public subnet and two private subnets using Pulumi in TypeScript. This setup provides a secure and scalable network infrastructure for your AWS resources.

Full Code Example

import * as pulumi from "@pulumi/pulumi";
import * as aws from "@pulumi/aws";

// Create a VPC
const vpc = new aws.ec2.Vpc("my-vpc", {
    cidrBlock: "10.0.0.0/16",
    enableDnsSupport: true,
    enableDnsHostnames: true,
    tags: { Name: "my-vpc" },
});

// Create a public subnet
const publicSubnet = new aws.ec2.Subnet("public-subnet", {
    vpcId: vpc.id,
    cidrBlock: "10.0.1.0/24",
    mapPublicIpOnLaunch: true,
    availabilityZone: "us-west-2a",
    tags: { Name: "public-subnet" },
});

// Create two private subnets
const privateSubnet1 = new aws.ec2.Subnet("private-subnet-1", {
    vpcId: vpc.id,
    cidrBlock: "10.0.2.0/24",
    availabilityZone: "us-west-2a",
    tags: { Name: "private-subnet-1" },
});

const privateSubnet2 = new aws.ec2.Subnet("private-subnet-2", {
    vpcId: vpc.id,
    cidrBlock: "10.0.3.0/24",
    availabilityZone: "us-west-2b",
    tags: { Name: "private-subnet-2" },
});

// Create an Internet Gateway
const internetGateway = new aws.ec2.InternetGateway("internet-gateway", {
    vpcId: vpc.id,
    tags: { Name: "internet-gateway" },
});

// Create a route table for the public subnet
const publicRouteTable = new aws.ec2.RouteTable("public-route-table", {
    vpcId: vpc.id,
    routes: [{
        cidrBlock: "0.0.0.0/0",
        gatewayId: internetGateway.id,
    }],
    tags: { Name: "public-route-table" },
});

// Associate the public subnet with the public route table
new aws.ec2.RouteTableAssociation("public-route-table-association", {
    subnetId: publicSubnet.id,
    routeTableId: publicRouteTable.id,
});

// Create route tables for the private subnets
const privateRouteTable1 = new aws.ec2.RouteTable("private-route-table-1", {
    vpcId: vpc.id,
    tags: { Name: "private-route-table-1" },
});

const privateRouteTable2 = new aws.ec2.RouteTable("private-route-table-2", {
    vpcId: vpc.id,
    tags: { Name: "private-route-table-2" },
});

// Associate the private subnets with their respective route tables
new aws.ec2.RouteTableAssociation("private-route-table-association-1", {
    subnetId: privateSubnet1.id,
    routeTableId: privateRouteTable1.id,
});

new aws.ec2.RouteTableAssociation("private-route-table-association-2", {
    subnetId: privateSubnet2.id,
    routeTableId: privateRouteTable2.id,
});

// Export the IDs of the created resources
export const vpcId = vpc.id;
export const publicSubnetId = publicSubnet.id;
export const privateSubnet1Id = privateSubnet1.id;
export const privateSubnet2Id = privateSubnet2.id;
export const internetGatewayId = internetGateway.id;
export const publicRouteTableId = publicRouteTable.id;
export const privateRouteTable1Id = privateRouteTable1.id;
export const privateRouteTable2Id = privateRouteTable2.id;