Rails asset pipeline not working in production environment? - ruby-on-rails-3.1

Question

I have recently upgraded an app from Rails 3.0 to 3.1. I have followed any instructions I could find for enabling the asset pipeline but it always fails when in the production environment:
<%= javascript_include_tag "application" %>
gives me
<script src="/javascripts/application.js" type="text/javascript"></script>
which is missing a digest and I get the following error:
cache: [GET /javascripts/application.js] miss
Started GET "/javascripts/application.js" for 127.0.0.1 at 2011-10-03 23:31:36 +0100
ActionController::RoutingError (No route matches [GET] "/javascripts/application.js"):
I've tried variations of these settings in application.rb:
require File.expand_path('../boot', __FILE__)
#require 'rails/all'
require "action_controller/railtie"
require "action_mailer/railtie"
require "active_resource/railtie"
require "rails/test_unit/railtie"
if defined?(Bundler)
# If you precompile assets before deploying to production, use this line
Bundler.require *Rails.groups(:assets => %w(development test))
# If you want your assets lazily compiled in production, use this line
# Bundler.require(:default, :assets, Rails.env)
end
module Blog
class Application < Rails::Application
config.autoload_paths += %W(#{config.root}/lib)
config.encoding = "utf-8"
config.filter_parameters += [:password]
config.assets.enabled = true
config.assets.version = '1.0'
end
end
and full production.rb (minus some comments)
Blog::Application.configure do
config.cache_classes = true
config.consider_all_requests_local = false
config.action_controller.perform_caching = true
config.serve_static_assets = false
config.assets.compress = true
config.assets.compile = false
config.assets.digest = true
config.i18n.fallbacks = true
config.active_support.deprecation = :notify
end
I have ran the rake assets:precompile task.
Am I missing any obvious steps?
Edit: Some additional details:
My assets are in app/assets folder. app/assets/images, app/assets/javascripts, app/assets/stylesheets, etc.
I see my files generated in my public/assets directory with names and digests.
app/assets/javascripts/application.js does indeed compile to something like public/assets/application-6ec417a53cb2bdb949966a153a61e7b1.js They end up in the public directory.

Answer 1

Sprockets is not getting loaded.
In an effort to remove active record in a previous version of rails (a la this question Remove ActiveRecord in Rails 3 (beta)) the require 'rails/all' was replaced by
require "action_controller/railtie"
require "action_mailer/railtie"
require "active_resource/railtie"
require "rails/test_unit/railtie"
What was missing here was sprockets/railtie

Answer 2

See the Upgrading to Rails 3.1 Railscast
Make sure your assets are in app/assets folder. app/assets/images, app/assets/javascripts, app/assets/stylesheets, etc.
Execute rake assets:precompile
You should see files generated in your app/public/assets directory with names and digests if enabled.
app/assets/javascripts/application.js would compile to /assets/application-6ec417a53cb2bdb949966a153a61e7b1.js
If the asset is named similar to above with a digest, Production.rb should have the following config:
# Generate digests for assets URLs
config.assets.digest = true
If you look at the web page source you should see something similar to the following:
<script src="/assets/application-6ec417a53cb2bdb949966a153a61e7b1.js" type="text/javascript"></script>
Try to manually load the file by going to http://example.com//assets/application-6ec417a53cb2bdb949966a153a61e7b1.js
The file should load, if not try checking permissions and further logs.