How to speed up your Rails app with Cloudfront and the asset pipeline

The article argues that using Cloudfront as an asset host can make Rails apps feel faster, especially for users with a fresh cache. It relies on the Rails asset pipeline fingerprinting files so Cloudfront can cache each version without cache invalidations.

Reading notes

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• It recommends Cloudfront for static assets such as CSS, JavaScript, and images.
• It warns against serving static assets directly from S3 because S3 is for storing files, not serving web traffic.
• Cloudfront serves files from edge cache locations close to the user.
• A distribution is set up with an origin, and requests are forwarded to the origin when Cloudfront does not have a cached copy.
• The post says Cloudfront can use a custom origin, not just S3 buckets.
• It suggests creating a distribution in the AWS management interface and testing asset URLs before changing Rails configuration.
• In Rails, setting asset_host in production.rb makes asset links point to the Cloudfront distribution.
• The asset pipeline appends a hash to asset filenames, so new file versions become distinct resources.
• Because of that fingerprinting, the post says syncing assets to S3 is not needed.
• The same fingerprinting also removes the need for cache invalidations when assets change.