Using Compass on Heroku: /tmp for stylesheets remotely and locally

Question

I'm currently using Compass with Heroku using this configuration recommended on the Heroku knowledge base. Heroku has a read-only file system, and so the compiled stylesheets need to be stored in /tmp. This works fine remotely on Heroku; locally, however, Rails expects to find stylesheets in /public/stylesheets (when called through = stylesheet_link_tag 'screen.css', :media => 'screen, projection').

In order to solve the problem, I have created symbolic links in /public/stylesheets using ln -s tmp/stylesheets/screen.css public/stylesheets/screen.css and that seems to work.

Is there a way to solve this problem without using symbolic links, perhaps by changing some configuration in Rails? I've poked around without much success.

Here is my config/initializers/compass.rb:

require 'compass'
require 'compass/app_integration/rails'
Compass::AppIntegration::Rails.initialize!

# Required for Heroku:
require 'fileutils'
FileUtils.mkdir_p(Rails.root.join("tmp", "stylesheets"))

Compass::AppIntegration::Rails.initialize!

Rails.configuration.middleware.delete('Sass::Plugin::Rack')
Rails.configuration.middleware.insert_before('Rack::Sendfile', 'Sass::Plugin::Rack')

Rails.configuration.middleware.insert_before('Rack::Sendfile', 'Rack::Static',
    :urls => ['/stylesheets'],
    :root => "#{Rails.root}/tmp")

And here is my config/compass.rb:

project_type = :rails
project_path = Compass::AppIntegration::Rails.root

# Set this to the root of your project when deployed:
http_path = "/"

# Necessary for Heroku (original commented out:
css_dir   = 'tmp/stylesheets'
#css_dir = "public/stylesheets/compiled"

sass_dir  = 'app/views/stylesheets'

environment = Compass::AppIntegration::Rails.env

Any help would be greatly appreciated.

Answer 1

I was actually just about to set up Compass with our Rails application, which is hosted on Heroku, so cheers for giving me an excuse to work through this. :)

The answer is simple:

Modify 'config/compass.rb':

project_type = :rails
project_path = Compass::AppIntegration::Rails.root

http_path = "/"

environment = Compass::AppIntegration::Rails.env
if environment == 'production'
  css_dir = "tmp/stylesheets"
  sass_dir = "app/views/stylesheets"
else
  css_dir = "public/stylesheets"
  sass_dir = "app/stylesheets"
end

Then modify 'config/initializers/compass.rb':

require 'compass'
require 'compass/app_integration/rails'
Compass::AppIntegration::Rails.initialize!

require 'fileutils'
FileUtils.mkdir_p(Rails.root.join("tmp", "stylesheets"))

environment = Compass::AppIntegration::Rails.env
if environment == 'production'
  Compass::AppIntegration::Rails.initialize!

  Rails.configuration.middleware.delete('Sass::Plugin::Rack')
  Rails.configuration.middleware.insert_before('Rack::Sendfile', 'Sass::Plugin::Rack')

  Rails.configuration.middleware.insert_before('Rack::Sendfile', 'Rack::Static',
      :urls => ['/stylesheets'],
      :root => "#{Rails.root}/tmp")
end

... and voila, you're good.