Virtual Private Cloud (VPC)

A Virtual Private Cloud (VPC) is a logically isolated section of the AWS cloud where you can launch AWS resources in a virtual network that you define. It provides you with complete control over your virtual networking environment, including the selection of your IP address range, creation of subnets, and configuration of route tables and network gateways.

Key Components of a VPC:

• IP Address Range: When you create a VPC, you specify the IP address range for the VPC in the form of a Classless Inter-Domain Routing (CIDR) block (e.g., 10.0.0.0/16).

• Subnets: Subnets partition the IP address range of your VPC. You can create both public and private subnets within a VPC.

• Route Tables: A route table contains a set of rules, called routes, that determine where network traffic is directed. Each subnet in your VPC must be associated with a route table.

• Internet Gateway: An internet gateway enables communication between your VPC and the internet. It serves as a gateway for traffic between the internet and the public subnets within your VPC.

Here's a Java example of creating a VPC with subnets, route tables, and an internet gateway:

1<class>Main {
2    public static void main(String[] args) {
3        // Define VPC with CIDR block
4        String vpcCidrBlock = "10.0.0.0/16";
5
6        // Create VPC
7        Vpc vpc = new Vpc(vpcCidrBlock);
8
9        // Define subnets with CIDR blocks
10        String publicSubnetCidrBlock = "10.0.1.0/24";
11        String privateSubnetCidrBlock = "10.0.2.0/24";
12
13        // Create subnets
14        Subnet publicSubnet = new Subnet(publicSubnetCidrBlock, SubnetType.PUBLIC);
15        Subnet privateSubnet = new Subnet(privateSubnetCidrBlock, SubnetType.PRIVATE);
16
17        // Associate subnets with VPC
18        vpc.addSubnet(publicSubnet);
19        vpc.addSubnet(privateSubnet);
20
21        // Define route tables
22        RouteTable publicRouteTable = new RouteTable();
23        RouteTable privateRouteTable = new RouteTable();
24
25        // Associate route tables with subnets
26        publicSubnet.associateRouteTable(publicRouteTable);
27        privateSubnet.associateRouteTable(privateRouteTable);
28
29        // Create internet gateway
30        InternetGateway internetGateway = new InternetGateway();
31
32        // Attach internet gateway to VPC
33        vpc.attachInternetGateway(internetGateway);
34
35        // Create default route from public subnet to internet gateway
36        publicRouteTable.addDefaultRoute(internetGateway);
37
38        // Generate CloudFormation template
39        String template = vpc.generateCloudFormationTemplate();
40
41        System.out.println(template);
42    }
43}

In this example, we define a VPC with a CIDR block of 10.0.0.0/16. We create two subnets: one public subnet with a CIDR block of 10.0.1.0/24 and one private subnet with a CIDR block of 10.0.2.0/24. We associate the subnets with the VPC, create route tables for each subnet, and associate the route tables with the subnets. We also create an internet gateway, attach it to the VPC, and create a default route from the public subnet to the internet gateway.

Finally, we generate a CloudFormation template for the VPC, which can be used to provision the VPC infrastructure in AWS.

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}

class Main {

    public static void main(String[] args) {

        // Define VPC with CIDR block

        String vpcCidrBlock = "10.0.0.0/16";

​

        // Create VPC

        Vpc vpc = new Vpc(vpcCidrBlock);

​

        // Define subnets with CIDR blocks

        String publicSubnetCidrBlock = "10.0.1.0/24";

        String privateSubnetCidrBlock = "10.0.2.0/24";

​

        // Create subnets

        Subnet publicSubnet = new Subnet(publicSubnetCidrBlock, SubnetType.PUBLIC);

        Subnet privateSubnet = new Subnet(privateSubnetCidrBlock, SubnetType.PRIVATE);

​

        // Associate subnets with VPC

        vpc.addSubnet(publicSubnet);

        vpc.addSubnet(privateSubnet);

​

        // Define route tables

        RouteTable publicRouteTable = new RouteTable();

        RouteTable privateRouteTable = new RouteTable();

​

        // Associate route tables with subnets

        publicSubnet.associateRouteTable(publicRouteTable);

        privateSubnet.associateRouteTable(privateRouteTable);

​

        // Create internet gateway