deploy.rb

set :assets_roles, :assets

after :compile_assets, :copy_manifest

task :copy_manifest do
  on roles(:assets) do
    within(shared_path) do
      set(:manifest_path, capture(:ls, '-t', 'public/assets/.sprockets-*.json', '|', 'head', '-n1'))
      set(:manifest_filename, fetch(:manifest_path).split('/').last)
      download!(fetch(:manifest_path), "tmp/#{fetch(:manifest_filename)}")
    end
  end
  on roles(:all) do
    within(shared_path) do
      execute(:rm, '-f', 'public/assets/.sprockets-*.json')
      upload!("tmp/#{fetch(:manifest_filename)}", fetch(:manifest_path))
    end
  end
end