How to set Cache-Control and Expires headers for Paperclip uploads.

In Ruby on Rails applications, gem Paperclip is often used with gem Fog, which has a feature of setting up Cache-Control and Expires headers for file uploads. Assuming, there is the following configuration in config/application.rb file:

 config.paperclip_defaults = {
   storage: :fog,
   fog_credentials: {
     provider: "Local",
     local_root: "#{Rails.root}/public"
   },
   fog_directory: "",
   fog_host: "localhost"
  }

Cache-Control and Expires headers can be set up by adding related attributes to the paperclip configuration:

config.paperclip_defaults = {
  ...previous code...

  fog_file: { 'Cache-Control' => 'max-age=86400',
              'Expires'       => 1.week.from_now.httpdate
    }
}

Remember that max-age is represented in seconds (so 86400 is 1 day).