Securing a load balancer with managed SSL certificates

Question

Pulumi · Accepted Answer

To secure a load balancer with managed SSL certificates, you will typically perform the following steps:

1. **Provision a Load Balancer:** Depending on the cloud provider, you would use Pulumi resources to create and configure a load balancer. This load balancer distributes incoming application traffic across multiple targets, such as servers or containers, in multiple Availability Zones.

2. **Provision an SSL Certificate:** You will need to provision a managed SSL/TLS certificate, which can be used to secure the communication with the load balancer. Cloud providers often offer services to manage SSL certificates, with some providing them for free.

3. **Attach the Certificate to the Load Balancer:** Once the certificate is provisioned, you can attach it to the load balancer's listener to ensure that traffic is encrypted.

Below is a TypeScript program that demonstrates how to create an AWS Load Balancer secured with a managed SSL certificate using Pulumi.

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

// Create a new security group for the load balancer that allows inbound traffic on port 443 (HTTPS)
const secGroup = new aws.ec2.SecurityGroup("securityGroup", {
    ingress: [
        { protocol: "tcp", fromPort: 443, toPort: 443, cidrBlocks: ["0.0.0.0/0"] },
    ],
});

// Provision a new certificate using AWS Certificate Manager (ACM)
const cert = new aws.acm.Certificate("certificate", {
    domainName: "example.com", // Replace with your domain name
    validationMethod: "DNS",   // This could also be "EMAIL" based on your preference
});

// Create an Application Load Balancer (ALB) to distribute incoming HTTPS traffic
const alb = new aws.lb.LoadBalancer("appLoadBalancer", {
    internal: false,
    securityGroups: [secGroup.id],
    subnets: ["subnet-XXXXXXXX"], // Replace with your subnet IDs
});

// Create a target group for the ALB to route requests to
const targetGroup = new aws.lb.TargetGroup("targetGroup", {
    port: 443,
    protocol: "HTTPS",
    targetType: "ip",
    vpcId: "vpc-XXXXXXXX", // Replace with your VPC ID
});

// Create a listener for the ALB that listens on port 443 and uses the certificate
const listener = new aws.lb.Listener("listener", {
    loadBalancerArn: alb.arn,
    port: 443,
    protocol: "HTTPS",
    sslPolicy: "ELBSecurityPolicy-2016-08", // Define the SSL policy for the listener
    certificateArn: cert.arn, // Use the ARN of the certificate we created earlier
    defaultActions: [{
        type: "forward",
        targetGroupArn: targetGroup.arn,
    }],
});

// Export the URLs of the load balancer and certificate for easy access
export const albUrl = alb.dnsName;
export const certArn = cert.arn;
```

This program completes the following:

- It creates a security group that allows HTTPS traffic.
- It requests a new managed certificate from AWS Certificate Manager.
- It provisions a new Application Load Balancer (ALB).
- It attaches the SSL certificate to the ALB via an HTTPS listener.

Please ensure that you replace `example.com`, `subnet-XXXXXXXX`, and `vpc-XXXXXXXX` with your domain name, subnet IDs, and VPC ID, respectively.

The output of this program will be the DNS name of the load balancer and the ARN of the SSL certificate. You can use these in your other systems, such as updating DNS records for domain names to point to the load balancer.

Keep in mind that there are some steps not covered here, such as domain validation for ACM which might require additional setup like adding a CNAME record to your DNS configuration, and provisioning compute resources to attach to the target group for the ALB to send traffic to. Also, when you set up an SSL/TLS certificate, you'll likely need to go through some process of proving you control the domain specified in the certificate request. This usually entails responding to an email or configuring a DNS record. Be prepared for this as part of provisioning a certificate.