Nick Little

VPC As A CloudFront Origin

Amazon Web Services (AWS) has just announced the ability to add Amazon CloudFront as an origin for Virtual Private Cloud (VPC) resource. To me, this is an absolute game changer. This new feature eliminates the need for public subnets, and ELB’s in many use cases, amd enhances security and simplified architecture.

In this blog post, I’ll explore the technical aspects of this feature, its benefits, and how it transforms the way applications are deployed in AWS.

It’s a pretty exciting feature, I have some customers who are very keen and have great needs to use it, so let’s get into it!

The Challenge with Public Subnets in Traditional Architectures

Historically, to expose application endpoints or content hosted in a VPC, you needed to deploy resources (such as Amazon EC2 instances, ECS tasks, or ALBs) in public subnets. This setup introduced several challenges:

  1. Security Risks: Public subnets require resources to have a public IP address, increasing the attack surface.
  2. Complex Networking: Maintaining and managing Network Address Translation (NAT) and public IP mappings for private resources often complicates networking configurations.
  3. Operational Overhead: Configuring firewalls, ingress rules, and ensuring secure access adds an additional layer of complexity.

These challenges necessitated intricate setups involving bastion hosts, NAT gateways, or VPNs to secure VPC resources while providing accessibility.

What’s New: CloudFront as a VPC Origin

AWS now allows you to configure CloudFront distributions with an origin that resides directly inside a VPC. This capability leverages AWS PrivateLink to securely connect CloudFront to private endpoints within the VPC, bypassing the need for a public IP address.

With this feature, you can serve content stored in Amazon S3 buckets, behind Application Load Balancers (ALB), or even directly from EC2 instances, without exposing those resources to the public internet. The integration happens over AWS PrivateLink, ensuring end-to-end encryption and private connectivity.

Benefits of Using CloudFront as a VPC Origin

  1. Enhanced Security:

    • By eliminating public subnets, resources no longer require public IPs, reducing the risk of external attacks.
    • All communication between CloudFront and the VPC happens over private connections secured by AWS PrivateLink**.

  2. Improved Performance:

    • CloudFront provides caching, compression, and optimization features, ensuring low latency and high-speed delivery.
    • Content can be cached at CloudFront edge locations, reducing the load on VPC resources.

  3. Simplified Architecture:

    • No need for NAT gateways, bastion hosts, or complex routing tables.
    • Simplifies compliance by keeping all VPC resources private while exposing only a secure CloudFront endpoint.

  4. Cost Efficiency:

    • Removes the need for NAT gateways and reduces data transfer costs since resources remain in private subnets.

Implementation Overview

Here’s how you can configure CloudFront with a VPC origin:

Step 1: Configure Your VPC Endpoint

  1. Create an Interface VPC Endpoint for your resource (e.g., ALB or EC2).
  2. Ensure the endpoint is associated with the required private subnets and security groups.

Step 2: Set Up CloudFront Distribution

  1. Create a new CloudFront distribution.
  2. For the origin, specify the VPC endpoint’s private DNS name or private IP address.

Step 3: Secure Access

  1. Use AWS IAM policies or Origin Access Control (OAC) to restrict access to resources.
  2. Apply CloudFront Functions** or Lambda@Edge for additional security and logic.

Use Cases

This feature unlocks several new possibilities:

  • Internal Applications: Use CloudFront to securely serve internal applications without public exposure.
  • Private APIs: Host APIs in private subnets and expose them via CloudFront for secure access.
  • Static Content Delivery: Store static assets in private S3 buckets and serve them globally with CloudFront.

Conclusion

The ability to use CloudFront as a VPC origin is a game-changer. It not only removes the need for public subnets but also enhances security, simplifies architecture, and reduces costs. Whether you’re hosting APIs, delivering static content, or serving internal applications, this feature ensures seamless integration with private VPC resources. AWS continues to make cloud architectures more secure, streamlined, and scalable—this is yet another step in that direction.

If you’re looking to modernize your infrastructure, now is the perfect time to leverage CloudFront as your secure gateway to the private resources in your VPC. And #deathtoallpublicsubnets and #publicELB’s :)