CloudFront Archives - ITS ☁ AWS

What is CloudFront Cache Invalidation?

CloudFront Cache Invalidation is a feature that allows you to remove outdated content from CloudFront edge locations, ensuring that your users see the most up-to-date version of your website. This is especially useful when you’ve made changes to your site and want to make sure everyone sees the latest updates. For example, if you’ve updated your website’s homepage, you can use CloudFront Cache Invalidation to remove the old version from the cache and replace it with the new one.

How do I invalidate my CloudFront cache?

To invalidate your CloudFront cache, you can use the AWS Management Console, the AWS CLI, or the CloudFront API. Here’s an example of how to do it using the AWS CLI:

aws cloudfront create-invalidation --distribution-id YOUR_DISTRIBUTION_ID --invalidation-batch "{"CallerReference":"YOUR_CALLER_REFERENCE","List":["/*"]}"

Make sure to replace YOUR_DISTRIBUTION_ID and YOUR_CALLER_REFERENCE with your actual distribution ID and caller reference.

What are some common use cases for CloudFront Cache Invalidation?

Some common use cases for CloudFront Cache Invalidation include:

Updating website content, such as blog posts or product descriptions

Changing website configurations, such as updating SSL certificates or modifying firewall rules

Deploying new website features or functionality

Any time you make changes to your website, you’ll want to use CloudFront Cache Invalidation to ensure that your users see the latest version.

How long does it take for CloudFront Cache Invalidation to take effect?

The time it takes for CloudFront Cache Invalidation to take effect can vary depending on the size of your distribution and the number of edge locations. However, in general, it can take anywhere from a few minutes to an hour for the invalidation to propagate to all edge locations. You can check the status of your invalidation request using the AWS Management Console or the AWS CLI.

Can I use CloudFront Cache Invalidation with other AWS services?

Yes, you can use CloudFront Cache Invalidation with other AWS services, such as S3, EC2, and Lambda. For example, you can use CloudFront Cache Invalidation to remove outdated content from an S3 bucket, or to update the configuration of an EC2 instance. The possibilities are endless, and using CloudFront Cache Invalidation with other AWS services can help you build a more scalable and efficient architecture.

What are some best practices for using CloudFront Cache Invalidation?

Some best practices for using CloudFront Cache Invalidation include:

Using a consistent naming convention for your distributions and invalidation requests

Testing your invalidation requests before deploying them to production

Monitoring your cache hit ratio and adjusting your invalidation strategy accordingly

By following these best practices, you can get the most out of CloudFront Cache Invalidation and ensure that your website is always running at peak performance.

And there you have it – a comprehensive guide to CloudFront Cache Invalidation! By mastering this powerful tool, you can ensure that your website is always running at peak performance and that your users see the latest and greatest version of your site. Dig deeper with our guides and learn more about how to optimize your website for maximum performance and scalability.

When integrating Azure Front Door with an AWS-hosted Single Page Application (SPA) on S3 + CloudFront, developers often encounter MIME type errors. A common issue is that scripts and stylesheets fail to load due to incorrect MIME types, leading to errors such as:

“Expected a JavaScript module script but the server responded with a MIME type of ‘text/html’.”

This typically happens due to misconfigurations in CloudFront, S3 bucket settings, or response headers. In this post, we’ll explore the root cause of these errors and how to properly configure your setup to ensure smooth redirection and loading of static assets.

fixing mime type errors when redirecting from azure front door to aws s3 cloudfront

The error is occuring is due to Azure Front Door incorrectly serving your AWS S3/CloudFront-hosted Single Page Application (SPA). The MIME type mismatch suggests that the frontend resources (JS, CSS) are being served as text/html instead of their correct content types. This is often caused by misconfigurations in Azure Front Door, S3, or CloudFront.

✅ Solutions

1. Ensure Proper MIME Types in S3

Your AWS S3 bucket must serve files with the correct MIME types.

Open AWS S3 Console → Select your Bucket → Properties → Scroll to “Static website hosting.”
Check the metadata of the files:
- JavaScript files should have Content-Type: application/javascript
- CSS files should have Content-Type: text/css
If incorrect, update them:
- Go to Objects → Select a file → Properties → Under “Metadata,” add the correct Content-Type.

Command to Fix for All Files

If you want to correct MIME types for all files at once, run this command:

aws s3 cp s3://your-bucket-name s3://your-bucket-name --recursive --metadata-directive REPLACE --content-type "application/javascript"

(Modify for CSS, images, etc.)

2. Verify CloudFront Behavior

CloudFront should correctly forward content with the right Content-Type.

Open AWS CloudFront Console → Select your distribution.
Check the “Behaviors”:
- Compress Objects Automatically: Yes
- Forward Headers: Whitelist “Origin” and “Content-Type”
- Object Caching: Respect Headers
- Query String Forwarding and Caching: Forward all, cache based on all
Purge Cache

sh

aws cloudfront create-invalidation --distribution-id YOUR_DISTRIBUTION_ID --paths "/*"

This clears any incorrect cached content.

3. Fix Azure Front Door Response Handling

Azure Front Door may be incorrectly handling responses from CloudFront.

Check Routing Rules:
- Go to Azure Portal → Front Door → Routing Rules.
- Ensure the Forwarding protocol is set to “Match incoming”.
- Caching must be disabled or set to “Use Origin Cache-Control.”
- Set Compression to gzip, br.
Enable Origin Custom Headers:
- Add a custom header to force correct MIME types:
Content-Type: application/javascript
Enable CORS Headers in S3 (if cross-origin issue arises):

json

[ { "AllowedHeaders": ["*"], "AllowedMethods": ["GET", "HEAD"], "AllowedOrigins": ["*"], "ExposeHeaders": [] } ]

📌 Summary

Step	Fix
✅ S3	Ensure correct MIME types (`application/javascript`, `text/css`)
✅ CloudFront	Forward headers (`Origin`, `Content-Type`), Purge cache
✅ Azure Front Door	Set correct routing, disable incorrect caching
✅ CORS	Allow cross-origin requests if needed

📚 References

Resolving MIME type errors when redirecting from Azure Front Door to an AWS-hosted SPA requires proper content-type handling, CloudFront behavior configurations, and ensuring correct headers are served from S3. By implementing the solutions outlined in this guide, you can avoid these errors and ensure your frontend application loads seamlessly.

If you’ve faced similar challenges or have additional insights, feel free to share your thoughts in the comments! 🚀

Tag: CloudFront

CloudFront Cache Invalidation