ActiveStorage Feature Request - Support for CDN (Cloudfront)

[eaconway]

Hello Rails team,

**Disclaimer: this is my first Github issue, so apologies if I'm missing something.

I've spent a fair amount of time researching and trialing how to setup Active Storage to leverage Cloudfront. There are a number of issues like:

• ActiveStorage: Allow access to backing file from Service API #31419 (Primary source)
• Active Storage with Cloudfront (usage) #33052
• https://stackoverflow.com/questions/52292961/using-cloudfront-with-active-storage

And even some pieces on other projects:

• Active Storage - CloudFlare - Image Caching & CDN spree/spree#9043

But can't seem to find a clear solution, or one sanctioned from Rails/Active Storage itself, so I believe this is still a bug. I'm looking for confirmation that this will be resolved in Rails 6 release (hopefully), or feedback from the team. Thanks!

Steps to reproduce

Setup basic rails project with Active storage. Set asset host to Cloudfront CDN (tried pointing CDN to S3 and project, or simply back to project itself). Unfortunately, Active Storage ignores asset_host and pulls directly from S3 regardless.

Expected behavior

When using a CDN to host files for site, specifically those user uploaded through Active Storage, Active Storage should run requests through CDN first when making download requests. Uploads should be through Active Storage current pathways, but once asset_host is set, downloads should flow through CDN.

Actual behavior

Currently, everything flows through Active Storage when trying to download/retrieve blobs, resulting in slow load times

System configuration

Rails version: 5.2.2

Ruby version: 2.5.1

[rafaelfranca]

Thank you so much for the issue but we don't take feature request on the issue tracker. We recommend you to try to implement the feature and send us a pull request or if you are in doubt if the feature will be accepts ask in Rails Core mailing list for feedback.

[collimarco]

Any updates on this with Rails 6? We also want to use Cloudfront in front of S3, as recommended by Amazon.

[collimarco]

Here's my final solution:
https://stackoverflow.com/a/59107484/51387

Basically for now I use sub on service_url.

[joshuacronemeyer]

Every once in awhile I come back to check on "ActiveStorage CDN support" and google always finds this rails issue. Active development on this can be found here. #34477

[equivalent]

I've found article where one dude manage to introduce CDN https://lipanski.com/posts/activestorage-cdn-rails-direct-route I've didn't try it yet (will do that in couple of weeks) Just posting it here if anyone find it useful

update

as @joshuacronemeyer recommends in comment bellow https://edgeguides.rubyonrails.org/active_storage_overview.html#putting-a-cdn-in-front-of-active-storage is much better solution

TL;DR I've summed up the CDN solution in https://blog.eq8.eu/til/rails-active-storage-cdn.html

related

• https://discuss.rubyonrails.org/t/putting-a-cdn-in-front-of-activestorage/76948/4
• https://github.com/rails/rails/pull/42363/files

[joshuacronemeyer]

@equivalent Rails active storage docs have a section on using a CDN. https://edgeguides.rubyonrails.org/active_storage_overview.html#putting-a-cdn-in-front-of-active-storage It's probably better to look there.

[zzak]

See: #42305