Rails: Bootstrap glyphicons not loading in production

Question

After upgrading to Rails 5, the Bootstrap glyphicon icons are not loading properly on heroku. For instance, the Trashcan icon is showing up as a question mark. It appears that the browser is not finding the glyphicon asset and loading its own interpretation. I am using bootstrap-sass 3.3.7.

When the glyphicons are loaded, if I open the console, I see errors like this:

A server with the specified hostname could not be found
https://assets/bootstrap/glyphicons-halflings-regular-fe185d11a49676890d47bb783312a0cda5a44c4039214094e7957b4c040ef11c.woff2

It looks to me that the asset host is not being set properly for the bootstrap assets. In my production.rb file, I have the line

config.asset_host = "https://#{ENV['RAILS_HOST_PATH']}"

and if I do heroku config --remote production, the value of RAILS_HOST_PATH is www.example.com.

If I look at Rails.application.config.asset_host it does correctly show "https://www.example.com". However it looks like for the bootstrap assets, the domain is resolved as https://.

What is going on here?

Answer 1

Further investigation revealed that it was not a problem with Rails 5 per se, but due to changing the production.rb file in upgrade, and following Heroku's advice on using ENV variables for such files.

Accordingly, I needed to specify the target RAILS_HOST_PATH in the precompilation i.e. RAILS_ENV=production RAILS_HOST_PATH=www.example.com rake assets:precompile