In today’s digital world, speed matters. AWS CloudFront is a Content Delivery Network (CDN) that helps you deliver your website or app content faster and more reliably to users around the globe. It works by caching your content on servers located worldwide and serving it from the one closest to the user. This reduces delays, improves performance, and ensures a smoother experience for everyone.

What is AWS CloudFront?

Think of CloudFront as a global network of servers that takes the heavy lifting off your main server. When someone visits your site or app, CloudFront delivers content (like images, videos, or even APIs) from the nearest server, making it faster and more efficient.

Key Benefits:

• Faster Load Times: Delivers content from the server closest to the user.
• Scalability: Handles high traffic automatically.
• Cost Optimization: Reduces load on your main server by caching frequently accessed content.

Key Concepts of CloudFont

These are the main ideas that explain how CloudFront works:

1. Edge Locations

These are servers located around the world where CloudFront caches your content. When a user makes a request, CloudFront serves it from the nearest edge location.

2. Origin

Your origin is where your content lives. This could be an Amazon S3 bucket, an EC2 instance, a load balancer, or even a custom server.

3. Distribution

A distribution is CloudFront’s setup that tells it where your content comes from, how it should be cached, and how to handle user requests.

4. Caching

CloudFront caches content at edge locations so users get it faster. If the content isn’t in the cache, CloudFront fetches it from the origin server.

5. Invalidation

When you update your content, you can remove old cached versions using invalidation. For a complete refresh, use the /* pattern to clear everything.

6. Viewer

A viewer is any device or app (like a browser or mobile app) accessing your content through CloudFront.

Cloudfront Behaviors

CloudFront allows you to define behaviors for different URL patterns within a distribution. For example, you can set different caching rules or origin settings for specific paths or file types.

Caching Policies

Caching policy in CloudFront determines how CloudFront caches and serves content to viewers. It allows you to control how frequently CloudFront retrieves content from your origin server and how long it keeps that content in its cache.

CloudFront provides two main types of caching policies:

1. Default Cache Behavior: This is the caching policy that applies to all requests that don't match any other cache behaviors you define. It allows you to set the default TTL (Time To Live) for your content, which determines how long CloudFront caches the content before checking for updates from the origin server. You can also configure additional settings like query string handling, cookies, and headers.
2. Custom Cache Behavior: This allows you to define specific caching policies for different types of content or specific paths on your website. For example, you can set different TTLs for static assets like images, CSS, or JavaScript files, compared to dynamic content that frequently changes. You can also configure other settings like compressing responses, forwarding cookies, or restricting access.

Origin Request Policy

Origin request policy in CloudFront controls how CloudFront interacts with your origin server when it needs to retrieve content that is not already cached. It allows you to define rules and restrictions on the requests that CloudFront sends to your origin server.

With origin request policies, you can:

• Modify Headers: You can add, remove, or modify headers in the requests that CloudFront sends to your origin server. This can be useful for adding authentication tokens, manipulating caching behavior, or customizing requests based on specific requirements.
• Restrict Methods: You can specify which HTTP methods are allowed or disallowed for requests to your origin server. For example, you can restrict CloudFront to only send GET requests and block other methods like POST or DELETE.
• Control Query Strings: You can control how CloudFront handles query strings in requests to your origin server. You can choose to forward all query strings, forward only specific query strings, or remove query strings altogether.

Use Case: API Servers

When using CloudFront to proxy requests to an API hosted on Kubernetes:

• Forward the host header to ensure requests are properly routed.
• Disable caching to ensure real-time responses.
• Update the ingress of your API server with the CloudFront domain.

Cloudfront Functions

CloudFront Functions let you run lightweight JavaScript code at AWS edge locations to customize content delivery. They’re ideal for tasks like URL rewrites, redirects, and header modifications.

Example: Handling Dynamic Pages

For apps like Next.js that use dynamic routes (e.g., /job/[id]), you can use custom cloudfront functions to ensure paths resolve correctly:

For [id] Pages:

function handler(event) {
    var request = event.request;
    var uri = request.uri;
    var parts = request.uri.split(`/`).filter(e => e);
    if (parts.length < 2) {
        return request;
    }
    parts.pop();
    request.uri = `/` + parts.join('/') + `/[id]/`;
    return request;
}

Conclusion

AWS CloudFront is a powerful and flexible solution to improve your website or application’s speed, scalability, and reliability. Whether you’re delivering static assets, managing APIs, or handling dynamic content, CloudFront provides the tools to meet your needs.

If you’re looking to optimize your application’s performance or build custom solutions tailored to your requirements, we’re here to help.

We specialize in creating complex custom software solutions. Feel free to reach out to us, and let’s build something amazing together!