Rails 3,HTTP扩展(WebDAV)和Rack App安装

Question

1以下更多内容是指代代码开发一个可以被认为是缺陷的rails的问题.
2我还要问一些了解得更好的人.

我想通过Warden身份验证将WebDAV添加到我的Rails 3应用程序中.我的warden中间件是通过Devise注入的.

http://github.com/chrisroberts/dav4rack
http://github.com/hassox/warden
http://github.com/plataformatec/devise

我无法从rails app(路由)中挂载DAV4Rack处理程序,如下所示:

# in config/routes.rb
mount DAV4Rack::Handler.new(
  :root => Rails.root.to_s, # <= it's just an example
  :root_uri_path => '/webdav',
  :resource_class => Dav::DocumentResource # <= my custom resource, you could use FileResource from dav4rack
), :at => "/webdav"

因为rails验证HTTP谓词(GET POST PUT ..),并且webdav使用像PROPFIND这样的HTTP扩展,但是没有验证,抛出以下异常:

ActionController::UnknownHttpMethod (PROPFIND, accepted HTTP methods are get, head, put, post, delete, and options)

此验证在ActionDispatch中进行:

/usr/local/lib/ruby/gems/1.9.1/gems/actionpack-3.0.0/lib/action_dispatch/http/request.rb +56 +72
in (56) "def request_method" and (72) "def method"

来自ActionDispatch的示例代码进行验证,以便明确:

def method
  @method ||= begin
    method = env["rack.methodoverride.original_method"] || env['REQUEST_METHOD']
    HTTP_METHOD_LOOKUP[method] || raise(ActionController::UnknownHttpMethod, "#{method}, accepted HTTP methods are #{HTTP_METHODS.to_sentence(:locale => :en)}")
    method
  end
end

从理论上讲,我们可以对此验证进行修补以符合webdav谓词,例如用于执行的railsdav项目(注意那里是rails 2,在rails 3中需要使用monkey-patch action_dispatch/http/request).

要将DAV4Rack处理程序添加到rails应用程序,我必须在ActionDispatch之外的机架级安装处理程序,如下所示:

# config.ru
require ::File.expand_path('../config/environment',  __FILE__)
require 'dav4rack/interceptor'
require 'dav/document_resource'

app = Rack::Builder.new{
  map '/webdav/' do
    run DAV4Rack::Handler.new(
      :root => Rails.root.to_s,
      :root_uri_path => '/webdav',
      :resource_class => Dav::DocumentResource
    )
  end

  map '/' do
    use DAV4Rack::Interceptor, :mappings => {
      '/webdav/' => {
        :resource_class => Dav::DocumentResource
      },
    }
    run Pmp::Application
  end
}.to_app
run app

现在我在我的应用程序中有Webdav支持.但它仍然需要身份验证,为此我想使用warden.

# in document_resource.rb
def check_authentication
  puts request.env['warden'] # nil :(
end

Warden是零,因为我的DAV4Rack :: Handler安装在会话之上并且监控中间件.使用"rake middleware"来检查我的堆栈,我可以看到以下内容:

> rake middleware 
use ActionDispatch::Static
use Rack::Lock
use ActiveSupport::Cache::Strategy::LocalCache
use Rack::Runtime
use Rails::Rack::Logger
use ActionDispatch::ShowExceptions
use ActionDispatch::RemoteIp
use Rack::Sendfile
use ActionDispatch::Callbacks
use ActiveRecord::ConnectionAdapters::ConnectionManagement
use ActiveRecord::QueryCache
use ActionDispatch::Cookies
use ActionDispatch::Session::CookieStore
use ActionDispatch::Flash
use ActionDispatch::ParamsParser
use Rack::MethodOverride
use ActionDispatch::Head
use ActionDispatch::BestStandardsSupport
use Warden::Manager
run Pmp::Application.routes

我相信通过使用DAV处理程序包装"Pmp :: Application.routes"(就像我在上面为config.ru中的"Pmp :: Application"所做的那样)会将我的webdav处理程序注入到正确位置的堆栈中以满足两者条件:

1. 在ActionDispatch方法验证代码之上,以避免ActionController :: UnknownHttpMethod
2. 低于会话和Warden :: Manager,所以我可以使用warden身份验证.

怎么做？看看"rake middleware"输出,显然可以覆盖"Pmp :: Application.routes"方法:

# in my app at APP_ROOT/config/application.rb
# override the routes method inherited from Rails::Application#routes
def routes
  routes_app = super
  app = Rack::Builder.new {
    map '/webdav/' do
      run DAV4Rack::Handler.new(
        :root => Rails.root.to_s,
        :root_uri_path => '/webdav',
        :resource_class => Dav::DocumentResource
      )
    end

    map '/' do
      use DAV4Rack::Interceptor, :mappings => {
        '/webdav/' => {
          :resource_class => Dav::DocumentResource
        },
      }
      run routes_app
    end
  }.to_app

  class << app; self end.class_eval do
    attr_accessor :routes_app
    def method_missing(sym, *args, &block)
      routes_app.send sym, *args, &block
    end
  end
  app.routes_app = routes_app

  app
end

因为我们的新机架应用程序"应用程序"将被问及链中的一些方法,即旧的机架应用程序"routes_app"用于重新加载,我们将theese委托给旧的原始应用程序"routes_app",带有一点method_missing魔法.

瞧,一切正常!巨大的成功.

只有一个问题:我不喜欢它.除了覆盖路线方法之外,必须有更好的方法来完成所有这些包络.

请注意,这不适用于乘客.最好的方法似乎是猴子修补铁轨.
请参阅:dav4rack wiki

大问题:

是否有更好的方法添加一个机架应用程序上面的"Pmp ::应用程序#路由"APP通过机架或其他方式???

大结论

1. routes.rb中的"mount"语义应该是机架级的(而不是rails/railtie/whatever),以这种方式允许对HTTP扩展进行处理,或者至少为这种情况设置一个方法"mount_rack"

Answer 1

我们有一个赢家. https://rails.lighthouseapp.com/projects/8994/tickets/5895-allow-mounting-of-rack-apps-that-deal-with-http-extensions