heroku assets not found 404

Question

We are dealing with an issue where our assets are compiling w/o any issues during slug compilation. However, starting yesterday after a push to both our staging and producti

Answer 1

I had the same issue. It seems to be fixed for me after including the rails_12factor gem in my production gems (in my Gemfile). I found this out after reading the first part of this Heroku Support page: https://devcenter.heroku.com/articles/rails4

Logging and assets

Heroku treats logs as streams and requires your logs to be sent to STDOUT. To enable STDOUT logging in Rails 4 you can add the rails_12factor gem. This gem will also configure your app to serve assets in production. To add this gem add this to your Gemfile:

gem 'rails_12factor', group: :production

This gem allows you to bring your application closer to being a 12factor application. You can get more information about how the gem configures logging and assets read the rails_12factor README. If this gem is not present in your application, you will receive a warning while deploying, and your assets and logs will not be functional.

The 'rails_12factor' gem has gem dependencies on the rails_serve_static_assets gem and rails_stdout_logging. Basically, if you don't want your Rails app using its precious cycles on processing requests just to serve assets then you'll need to figure out a different solution such as a CDN: https://devcenter.heroku.com/articles/using-amazon-cloudfront-cdn-with-rails