Rails 4 static site generation

application.rb

# config/application.rb


module AssetsInitializers
  class Railtie < Rails::Railtie
    initializer "assets_initializers.initialize_rails",
                :group => :assets do |app|
      require "#{Rails.root}/config/initializers/sprockets_patch.rb"
    end
  end
end

assets.rake

# lib/tasks/assets.rake


Rake::Task["assets:precompile"].enhance do
  Rake::Task["assets:regurgitate_digested_assets"].invoke
end

Rake::Task["assets:clean"].clear

namespace :assets do

  logger = Logger.new($stderr)

  task :regurgitate_digested_assets => :environment do
    manifest_path = Dir.glob(File.join(Rails.root, 'public/assets/.sprockets-manifest-*.json')).first
    manifest_data = JSON.load(File.new(manifest_path))

    regurgitated_assets = {}

    manifest_data["assets"].each do |logical_path, digested_path|
      full_digested_path    = File.join(Rails.root, 'public/assets', digested_path)
      full_nondigested_path = File.join(Rails.root, 'public/assets', logical_path)

      logger.info "(Regurgitate) Copying to #{full_nondigested_path}"

      regurgitated_assets[logical_path] = logical_path

      if File.extname(full_digested_path) == '.css'
        logger.info "(Regurgitate) Removing digest hashes from css file"
        css = File.read(full_digested_path)
        digests_removed = css.gsub(/(-{1}[a-z0-9]{32}*\.{1}){1}/, '.')
        File.open(full_nondigested_path, "w") { |file| file.puts digests_removed }
      else
        # Use FileUtils.copy_file with true third argument to copy
        # file attributes (eg mtime) too, as opposed to FileUtils.cp
        FileUtils.copy_file full_digested_path, full_nondigested_path, true
      end
    end

    manifest_data["assets"] = manifest_data["assets"].merge(regurgitated_assets)

    File.open(manifest_path, 'w') { |file| file.write(manifest_data.to_json) }
  end

  task :clean => :environment do
    logger.info "Skipping asset cleaning, we like it dirty!"
  end
end

production.rb

 # config/environments/production.rb
 #
 # Can also be set to false, but this is better
 
 config.assets.digest = !ENV['RAILS_DISABLE_DIGEST'].present?

sprockets_patch.rb

# config/initializers/sprockets_patch.rb
#
# We don't want to compute the paths anymore, just return them

Sprockets::Rails::Helper.class_eval do
  def compute_asset_path(path, options = {})
    File.join(assets_prefix, path)
  end
end

Build the site via:

wget -mnH -k --html-extension http://codebase.herokuapp.com/