How to upgrade to Rails4 with Heroku

Rails migrations are never easy. But the community does it’s best to help you out. Here are some tips that helped me migrate my app:

Watch this video by Ryan Bates – Upgrading to Rails4

Check out these links

https://devcenter.heroku.com/articles/rails4-getting-started
https://devcenter.heroku.com/articles/multiple-environments

And then see if you run into any other problems like these:

Asset pipeline fails when deploying to Heroku Rails4

If you get this kind of error message

Preparing app for Rails asset pipeline
Running: rake assets:precompile
rake aborted!
could not connect to server: Connection refused
Is the server running on host “127.0.0.1″ and accepting

Try this from the command line:

> heroku labs:enable user-env-compile -a

You can get the name of your app be typing:

> heroku apps

http://stackoverflow.com/questions/16432825/heroku-precompile-assets-failed-on-rail-4-app

Images not showing up

If you deploy but no images show up try this:

production.rb

config.cache_classes = true
config.serve_static_assets = true
config.assets.compile = true
config.assets.digest = true

http://stackoverflow.com/questions/16271696/cant-get-css-working-on-heroku-using-rails-4-with-bootstrap-saas-gem

Misc

Other things to try

SampleApp::Application.configure do
  config.serve_static_assets = true
end

http://stackoverflow.com/questions/15354539/heroku-does-not-compile-files-under-assets-piplines-in-rails-4

Links that help

https://devcenter.heroku.com/articles/rails-asset-pipeline