Ruby on rails 在导轨中安装机架应用程序不起作用

我正在尝试在Rails中安装rack应用程序，但它不起作用。我已经重新创建了问题的最简单版本。我正在使用Ruby 1.9.3p327和Rails 3.2.11

我首先使用

rails新问题\u示例
创建了一个新的rails应用程序。切换到problem_example目录后，我可以访问rails应用程序
http://localhost:3000
生活是美好的

按照中的说明，我在路线中添加了以下内容：

ProblemExample::Application.routes.draw do
  root :to => proc { |env| [200, {}, ["Oh yeah!"]] }
end

我还从公用文件夹中删除了index.html文件。如果我导航到
http://localhost:3000
，我看到“哦，耶！”输出到我的屏幕上

这是棘手的部分。如果我将路线修改为如下所示：

class SimpleRackApplication
  def call(env)
    [200, {'Content-Type' => 'text/plain'}, ["Oh no!"]]
  end
end

ProblemExample::Application.routes.draw do
  root :to => SimpleRackApplication
end

当我运行
rails s
，我得到了一个错误：

=> Booting WEBrick
=> Rails 3.2.11 application starting in development on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
Exiting
/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action_dispatch/routing/mapper.rb:181:in `default_controller_and_action': missing :controller (ArgumentError)
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action_dispatch/routing/mapper.rb:78:in `normalize_options!'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action_dispatch/routing/mapper.rb:61:in `initialize'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action_dispatch/routing/mapper.rb:1304:in `new'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action_dispatch/routing/mapper.rb:1304:in `add_route'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action_dispatch/routing/mapper.rb:1284:in `decomposed_match'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action_dispatch/routing/mapper.rb:1270:in `block in match'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action_dispatch/routing/mapper.rb:1270:in `each'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action_dispatch/routing/mapper.rb:1270:in `match'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action_dispatch/routing/mapper.rb:260:in `root'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action_dispatch/routing/mapper.rb:1317:in `root'
    from /Users/landonschropp/Dropbox/Development/current/problem_example/config/routes.rb:9:in `block in <top (required)>'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action_dispatch/routing/route_set.rb:282:in `instance_exec'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action_dispatch/routing/route_set.rb:282:in `eval_block'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action_dispatch/routing/route_set.rb:260:in `draw'
    from /Users/landonschropp/Dropbox/Development/current/problem_example/config/routes.rb:8:in `<top (required)>'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activesupport-3.2.11/lib/active_support/dependencies.rb:245:in `load'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activesupport-3.2.11/lib/active_support/dependencies.rb:245:in `block in load'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activesupport-3.2.11/lib/active_support/dependencies.rb:236:in `load_dependency'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activesupport-3.2.11/lib/active_support/dependencies.rb:245:in `load'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/application/routes_reloader.rb:40:in `block in load_paths'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/application/routes_reloader.rb:40:in `each'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/application/routes_reloader.rb:40:in `load_paths'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/application/routes_reloader.rb:16:in `reload!'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/application/routes_reloader.rb:26:in `block in updater'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activesupport-3.2.11/lib/active_support/file_update_checker.rb:78:in `call'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activesupport-3.2.11/lib/active_support/file_update_checker.rb:78:in `execute'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/application/routes_reloader.rb:27:in `updater'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/application/routes_reloader.rb:7:in `execute_if_updated'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/application/finisher.rb:66:in `block in <module:Finisher>'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/initializable.rb:30:in `instance_exec'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/initializable.rb:30:in `run'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/initializable.rb:55:in `block in run_initializers'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/initializable.rb:54:in `each'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/initializable.rb:54:in `run_initializers'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/application.rb:136:in `initialize!'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/railtie/configurable.rb:30:in `method_missing'
    from /Users/landonschropp/Dropbox/Development/current/problem_example/config/environment.rb:5:in `<top (required)>'
    from /Users/landonschropp/Dropbox/Development/current/problem_example/config.ru:3:in `require'
    from /Users/landonschropp/Dropbox/Development/current/problem_example/config.ru:3:in `block in <main>'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/rack-1.4.4/lib/rack/builder.rb:51:in `instance_eval'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/rack-1.4.4/lib/rack/builder.rb:51:in `initialize'
    from /Users/landonschropp/Dropbox/Development/current/problem_example/config.ru:in `new'
    from /Users/landonschropp/Dropbox/Development/current/problem_example/config.ru:in `<main>'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/rack-1.4.4/lib/rack/builder.rb:40:in `eval'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/rack-1.4.4/lib/rack/builder.rb:40:in `parse_file'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/rack-1.4.4/lib/rack/server.rb:200:in `app'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/commands/server.rb:46:in `app'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/rack-1.4.4/lib/rack/server.rb:304:in `wrapped_app'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/rack-1.4.4/lib/rack/server.rb:254:in `start'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/commands/server.rb:70:in `start'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/commands.rb:55:in `block in <top (required)>'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/commands.rb:50:in `tap'
    from /Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/commands.rb:50:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'

=>启动WEBrick
=>Rails 3.2.11应用程序在上开始开发http://0.0.0.0:3000
=>使用-d调用以分离
=>Ctrl-C关闭服务器
退出
/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action\u dispatch/routing/mapper.rb:181:'default\u controller\u and\u action'中：缺少控制器（ArgumentError）
来自/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action\u dispatch/routing/mapper.rb:78:in“normalize\u options！”
来自/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action\u dispatch/routing/mapper.rb:61:“初始化”中
来自/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action\u dispatch/routing/mapper.rb:1304:in“new”
来自/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action\u dispatch/routing/mapper.rb:1304:“添加路由”中
来自/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action\u dispatch/routing/mapper.rb:1284:in“分解匹配”
来自/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action\u dispatch/routing/mapper.rb:1270:“匹配中的块”
来自/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action\u dispatch/routing/mapper.rb:1270:in“each”
来自/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action\u dispatch/routing/mapper.rb:1270:in“match”中
来自/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action\u dispatch/routing/mapper.rb:260:in'root'
from/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action\u dispatch/routing/mapper.rb:1317:in'root'
from/Users/landonschropp/Dropbox/Development/current/problem\u example/config/routes.rb:9:in'block in'
from/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action\u dispatch/routing/route\u set.rb:282:in'instance\u exec'
from/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action\u dispatch/routing/route\u set.rb:282:in'eval_block'
from/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/actionpack-3.2.11/lib/action\u dispatch/routing/route\u set.rb:260:in'draw'
来自/Users/landonschropp/Dropbox/Development/current/problem\u example/config/routes.rb:8:in`'
来自/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activesupport-3.2.11/lib/active\u support/dependencies.rb:245:在“加载”中
来自/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activesupport-3.2.11/lib/active\u support/dependencies.rb:245:“加载中的块”中
来自/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activesupport-3.2.11/lib/active\u support/dependencies.rb:236:“加载依赖项”中
来自/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activesupport-3.2.11/lib/active\u support/dependencies.rb:245:在“加载”中
from/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/application/routes\u reloader.rb:40:“加载路径中的块”
from/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/application/routes\u reloader.rb:40:in“each”
from/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/application/routes\u reloader.rb:40:“加载路径”中
from/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/application/routes\u reloader.rb:16:in“reload！”
来自/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/application/routes\u reloader.rb:26:“更新程序中的块”
来自/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activesupport-3.2.11/lib/active\u support/file\u update\u checker.rb:78:“调用”中
来自/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/activesupport-3.2.11/lib/active\u support/file\u update\u checker.rb:78:“执行”中
来自/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/application/routes\u reloader.rb:27:“更新程序”中
from/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/application/routes\u reloader.rb:7:“更新后执行”中
from/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/application/finisher.rb:66:in'block in'
from/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/initializable.rb:30:in'instance_exec'
来自/Users/landonschropp/.rbenv/versions/1.9.3-p327/lib/ruby/gems/1.9.1/gems/railties-3.2.11/lib/rails/initializable.rb:30:在“运行”中
来自/Users/landonschropp/.rbenv
root :to => SimpleRackApplication.new