ruby-on-rails - rails_admin 从事开发工作但不从事生产或 heroku

Question

我有一个非常基本的 Rails 3.1rc6 应用程序，上面基本上只有 Devise、CanCan 和 rails_admin，以及一些非常简单的模型。

在开发环境中 rails_admin 工作正常，我可以点击 localhost:3000/admin 并以我的管理员用户登录后，我可以看到所有数据并进行管理。

但是当我部署到 Heroku 并尝试点击 appname.herokuapp.com/admin 时，我得到“您要查找的页面不存在。您可能输入了错误的地址或页面可能已经移动了”。这是来自 Heroku 日志的尾部:

app[web.1]: 
app[web.1]: 
app[web.1]: Started GET "/admin" for 79.157.xx.xx at 2011-08-24 12:15:52 +0000
app[web.1]: 
app[web.1]: ActionController::RoutingError (No route matches {:controller=>"home"}):
heroku[router]: GET appname.herokuapp.com/admin dyno=web.1 queue=0 wait=0ms service=7ms status=404 bytes=728
app[web.1]:   app/controllers/application_controller.rb:5:in `block in <class:ApplicationController>'
app[web.1]: 
app[web.1]: 
app[web.1]: cache: [GET /admin] miss
app[web.1]:   Processing by RailsAdmin::MainController#index as HTML
app[web.1]: Completed 404 Not Found in 2ms

所有其他路线(基本上是设计路线)都可以正常工作。

在我的本地机器上运行 Thin in production(我在 Heroku 中使用的网络服务器)时，我得到了同样的结果:

$ bundle exec rails server thin -e production
=> Booting Thin
=> Rails 3.1.0.rc6 application starting in production on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
Sprockets::Environment#static_root is deprecated
>> Thin web server (v1.2.11 codename Bat-Shit Crazy)
>> Maximum connections set to 1024
>> Listening on 0.0.0.0:3000, CTRL+C to stop

cache: [GET /admin] miss


Started GET "/admin" for 127.0.0.1 at 2011-08-24 13:49:42 +0200
  Processing by RailsAdmin::MainController#index as HTML
Completed 404 Not Found in 3ms

ActionController::RoutingError (No route matches {:controller=>"home"}):
  app/controllers/application_controller.rb:5:in `block in <class:ApplicationController>'

Rendered /home/mccoy/.rvm/gems/ruby-1.9.2-p290@talleres-r31/gems/actionpack-3.1.0.rc6/lib/action_dispatch/middleware/templates/rescues/routing_error.erb within rescues/layout (0.9ms)

在浏览器上

Routing Error

No route matches {:controller=>"home"}

这是我的routes.rb

root :to => "home#index"
devise_for :users
resources :users, :only => :show
mount RailsAdmin::Engine => '/admin', :as => 'rails_admin'

初始值设定项/rails_admin.rb

RailsAdmin.config do |config|
  config.authorize_with :cancan
  config.reload_between_requests = false
end

这里是 heroku 上的路由

$ heroku run rake routes
Running rake routes attached to terminal... up, run.8
                    root        /                              {:controller=>"home", :action=>"index"}
        new_user_session GET    /users/sign_in(.:format)       {:action=>"new", :controller=>"devise/sessions"}
            user_session POST   /users/sign_in(.:format)       {:action=>"create", :controller=>"devise/sessions"}
    destroy_user_session GET    /users/sign_out(.:format)      {:action=>"destroy", :controller=>"devise/sessions"}
           user_password POST   /users/password(.:format)      {:action=>"create", :controller=>"devise/passwords"}
       new_user_password GET    /users/password/new(.:format)  {:action=>"new", :controller=>"devise/passwords"}
      edit_user_password GET    /users/password/edit(.:format) {:action=>"edit", :controller=>"devise/passwords"}
                         PUT    /users/password(.:format)      {:action=>"update", :controller=>"devise/passwords"}
cancel_user_registration GET    /users/cancel(.:format)        {:action=>"cancel", :controller=>"devise/registrations"}
       user_registration POST   /users(.:format)               {:action=>"create", :controller=>"devise/registrations"}
   new_user_registration GET    /users/sign_up(.:format)       {:action=>"new", :controller=>"devise/registrations"}
  edit_user_registration GET    /users/edit(.:format)          {:action=>"edit", :controller=>"devise/registrations"}
                         PUT    /users(.:format)               {:action=>"update", :controller=>"devise/registrations"}
                         DELETE /users(.:format)               {:action=>"destroy", :controller=>"devise/registrations"}
                    user GET    /users/:id(.:format)           {:action=>"show", :controller=>"users"}
             rails_admin        /admin                         {:to=>RailsAdmin::Engine}

最后这里是本地路线……一样!

$ rake routes
                    root        /                              {:controller=>"home", :action=>"index"}
        new_user_session GET    /users/sign_in(.:format)       {:action=>"new", :controller=>"devise/sessions"}
            user_session POST   /users/sign_in(.:format)       {:action=>"create", :controller=>"devise/sessions"}
    destroy_user_session GET    /users/sign_out(.:format)      {:action=>"destroy", :controller=>"devise/sessions"}
           user_password POST   /users/password(.:format)      {:action=>"create", :controller=>"devise/passwords"}
       new_user_password GET    /users/password/new(.:format)  {:action=>"new", :controller=>"devise/passwords"}
      edit_user_password GET    /users/password/edit(.:format) {:action=>"edit", :controller=>"devise/passwords"}
                         PUT    /users/password(.:format)      {:action=>"update", :controller=>"devise/passwords"}
cancel_user_registration GET    /users/cancel(.:format)        {:action=>"cancel", :controller=>"devise/registrations"}
       user_registration POST   /users(.:format)               {:action=>"create", :controller=>"devise/registrations"}
   new_user_registration GET    /users/sign_up(.:format)       {:action=>"new", :controller=>"devise/registrations"}
  edit_user_registration GET    /users/edit(.:format)          {:action=>"edit", :controller=>"devise/registrations"}
                         PUT    /users(.:format)               {:action=>"update", :controller=>"devise/registrations"}
                         DELETE /users(.:format)               {:action=>"destroy", :controller=>"devise/registrations"}
                    user GET    /users/:id(.:format)           {:action=>"show", :controller=>"users"}
             rails_admin        /admin                         {:to=>RailsAdmin::Engine}

知道为什么 rails_admin 路由在开发中有效但在生产中无效吗？我该怎么做才能解决这个问题？

万一它有帮助，当我在生产环境中运行 WEBrick 时它失败了

$ rails s production
Exiting
/home/mccoy/.rvm/gems/ruby-1.9.2-p290@talleres-r31/gems/activesupport-3.1.0.rc6/lib/active_support/dependencies.rb:237:in `require': no such file to load -- rack/handler/production (LoadError)
    from /home/mccoy/.rvm/gems/ruby-1.9.2-p290@talleres-r31/gems/activesupport-3.1.0.rc6/lib/active_support/dependencies.rb:237:in `block in require'
    from /home/mccoy/.rvm/gems/ruby-1.9.2-p290@talleres-r31/gems/activesupport-3.1.0.rc6/lib/active_support/dependencies.rb:223:in `block in load_dependency'
    from /home/mccoy/.rvm/gems/ruby-1.9.2-p290@talleres-r31/gems/activesupport-3.1.0.rc6/lib/active_support/dependencies.rb:636:in `new_constants_in'
    from /home/mccoy/.rvm/gems/ruby-1.9.2-p290@talleres-r31/gems/activesupport-3.1.0.rc6/lib/active_support/dependencies.rb:223:in `load_dependency'
    from /home/mccoy/.rvm/gems/ruby-1.9.2-p290@talleres-r31/gems/activesupport-3.1.0.rc6/lib/active_support/dependencies.rb:237:in `require'
    from /home/mccoy/.rvm/gems/ruby-1.9.2-p290@talleres-r31/gems/rack-1.3.2/lib/rack/handler.rb:63:in `try_require'
    from /home/mccoy/.rvm/gems/ruby-1.9.2-p290@talleres-r31/gems/rack-1.3.2/lib/rack/handler.rb:16:in `get'
    from /home/mccoy/.rvm/gems/ruby-1.9.2-p290@talleres-r31/gems/rack-1.3.2/lib/rack/server.rb:269:in `server'
    from /home/mccoy/.rvm/gems/ruby-1.9.2-p290@talleres-r31/gems/railties-3.1.0.rc6/lib/rails/commands/server.rb:59:in `start'
    from /home/mccoy/.rvm/gems/ruby-1.9.2-p290@talleres-r31/gems/railties-3.1.0.rc6/lib/rails/commands.rb:54:in `block in <top (required)>'
    from /home/mccoy/.rvm/gems/ruby-1.9.2-p290@talleres-r31/gems/railties-3.1.0.rc6/lib/rails/commands.rb:49:in `tap'
    from /home/mccoy/.rvm/gems/ruby-1.9.2-p290@talleres-r31/gems/railties-3.1.0.rc6/lib/rails/commands.rb:49:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'

但我认为这更像是我这边的 gem/config 问题，而不是任何相关问题。尽管在开发环境中工作正常。

Answer 1

经过进一步(非常痛苦)的调查，我发现这是由 cancan 而不是 rails_admin 引起的。

生产数据库中的测试用户没有分配正确的角色，因此无权访问 rails_admin。这引发了相应的 AccessDenied 异常，该异常在 application_controller.rb 中由

rescue_from CanCan::AccessDenied do |exception|
    redirect_to root_url, :alert => exception.message
end

但由于某些原因 redirect_to root_url 因上述路由错误而失败。似乎我不是唯一遇到这个问题的人，在阅读了这个 Unresolved 问题后 https://github.com/ryanb/cancan/issues/443

开发数据库中的测试用户具有正确的角色，可以正确访问 rails_admin，这使得调试变得非常令人沮丧。

至少现在我走对了路!