Rails 3, Mailgun, HTTP POST - undefined method `rewind' for String

[Brandon Casci]

If you haven't used mailgun before, it's a pretty interesting service. Programmable mailboxes. It's very handy for incoming mail because you can set it up to route incoming e-mails to different url's based on patterns in the send-to header.

Rails doesn't seem to like it's posts though. Maybe it's a bug?

I tried swapping out webrick for other servers...seems like the problem is in rails, but I'm having trouble understanding the true nature of the problem. Got any theories?

my test method on the posts controller...

  def upload
    render :nothing => true
  end

Error during failsafe response: ActionView::Template::Error
  /usr/lib/ruby/gems/1.8/gems/activesupport-3.0.4/lib/active_support/whiny_nil.rb:48:in `method_missing'
  /usr/lib/ruby/gems/1.8/gems/actionpack-3.0.4/lib/action_dispatch/http/parameters.rb:10:in `parameters'
  /usr/lib/ruby/gems/1.8/gems/actionpack-3.0.4/lib/action_dispatch/middleware/templates/rescues/diagnostics.erb:3:in `__usr_lib_ruby_gems_____gems_actionpack_______lib_action_dispatch_middleware_templates_rescues_diagnostics_erb___359554262__611779798_0'
  /usr/lib/ruby/gems/1.8/gems/actionpack-3.0.4/lib/action_view/template.rb:135:in `send'
  /usr/lib/ruby/gems/1.8/gems/actionpack-3.0.4/lib/action_view/template.rb:135:in `render'
  /usr/lib/ruby/gems/1.8/gems/activesupport-3.0.4/lib/active_support/notifications.rb:54:in `instrument'
  /usr/lib/ruby/gems/1.8/gems/actionpack-3.0.4/lib/action_view/template.rb:127:in `render'
  /usr/lib/ruby/gems/1.8/gems/actionpack-3.0.4/lib/action_view/render/rendering.rb:59:in `_render_template'
  /usr/lib/ruby/gems/1.8/gems/activesupport-3.0.4/lib/active_support/notifications.rb:52:in `instrument'
  /usr/lib/ruby/gems/1.8/gems/activesupport-3.0.4/lib/active_support/notifications/instrumenter.rb:21:in `instrument'
  /usr/lib/ruby/gems/1.8/gems/activesupport-3.0.4/lib/active_support/notifications.rb:52:in `instrument'
  /usr/lib/ruby/gems/1.8/gems/actionpack-3.0.4/lib/action_view/render/rendering.rb:56:in `_render_template'
  /usr/lib/ruby/gems/1.8/gems/actionpack-3.0.4/lib/action_view/render/rendering.rb:26:in `render'
  /usr/lib/ruby/gems/1.8/gems/actionpack-3.0.4/lib/action_dispatch/middleware/show_exceptions.rb:88:in `rescue_action_locally'
  /usr/lib/ruby/gems/1.8/gems/actionpack-3.0.4/lib/action_dispatch/middleware/show_exceptions.rb:68:in `render_exception'
  /usr/lib/ruby/gems/1.8/gems/actionpack-3.0.4/lib/action_dispatch/middleware/show_exceptions.rb:59:in `call'
  /usr/lib/ruby/gems/1.8/gems/railties-3.0.4/lib/rails/rack/logger.rb:13:in `call'
  /usr/lib/ruby/gems/1.8/gems/rack-1.2.1/lib/rack/runtime.rb:17:in `call'
  /usr/lib/ruby/gems/1.8/gems/activesupport-3.0.4/lib/active_support/cache/strategy/local_cache.rb:72:in `call'
  /usr/lib/ruby/gems/1.8/gems/rack-1.2.1/lib/rack/lock.rb:11:in `call'
  /usr/lib/ruby/gems/1.8/gems/rack-1.2.1/lib/rack/lock.rb:11:in `synchronize'
  /usr/lib/ruby/gems/1.8/gems/rack-1.2.1/lib/rack/lock.rb:11:in `call'
  /usr/lib/ruby/gems/1.8/gems/actionpack-3.0.4/lib/action_dispatch/middleware/static.rb:30:in `call'
  /usr/lib/ruby/gems/1.8/gems/railties-3.0.4/lib/rails/application.rb:168:in `call'
  /usr/lib/ruby/gems/1.8/gems/railties-3.0.4/lib/rails/application.rb:77:in `send'
  /usr/lib/ruby/gems/1.8/gems/railties-3.0.4/lib/rails/application.rb:77:in `method_missing'
  /usr/lib/ruby/gems/1.8/gems/railties-3.0.4/lib/rails/rack/log_tailer.rb:14:in `call'
  /usr/lib/ruby/gems/1.8/gems/rack-1.2.1/lib/rack/content_length.rb:13:in `call'
  /usr/lib/ruby/gems/1.8/gems/rack-1.2.1/lib/rack/handler/webrick.rb:52:in `service'
  /usr/lib/ruby/1.8/webrick/httpserver.rb:104:in `service'
  /usr/lib/ruby/1.8/webrick/httpserver.rb:65:in `run'
  /usr/lib/ruby/1.8/webrick/server.rb:173:in `start_thread'
  /usr/lib/ruby/1.8/webrick/server.rb:162:in `start'
  /usr/lib/ruby/1.8/webrick/server.rb:162:in `start_thread'
  /usr/lib/ruby/1.8/webrick/server.rb:95:in `start'
  /usr/lib/ruby/1.8/webrick/server.rb:92:in `each'
  /usr/lib/ruby/1.8/webrick/server.rb:92:in `start'
  /usr/lib/ruby/1.8/webrick/server.rb:23:in `start'
  /usr/lib/ruby/1.8/webrick/server.rb:82:in `start'
  /usr/lib/ruby/gems/1.8/gems/rack-1.2.1/lib/rack/handler/webrick.rb:13:in `run'
  /usr/lib/ruby/gems/1.8/gems/rack-1.2.1/lib/rack/server.rb:213:in `start'
  /usr/lib/ruby/gems/1.8/gems/railties-3.0.4/lib/rails/commands/server.rb:65:in `start'
  /usr/lib/ruby/gems/1.8/gems/railties-3.0.4/lib/rails/commands.rb:30
  /usr/lib/ruby/gems/1.8/gems/railties-3.0.4/lib/rails/commands.rb:27:in `tap'
  /usr/lib/ruby/gems/1.8/gems/railties-3.0.4/lib/rails/commands.rb:27
  script/rails:6:in `require'
  script/rails:6


Started POST "/posts/upload" for 174.37.214.196 at Fri Mar 11 19:22:41 -0500 2011
  SQL (0.1ms)  SET search_path TO public
  SQL (0.2ms)  SHOW client_min_messages
  SQL (0.1ms)  SET client_min_messages TO 'panic'
  SQL (0.1ms)  SET standard_conforming_strings = on
  SQL (0.1ms)  SET client_min_messages TO 'notice'
  SQL (0.3ms)  SET time zone 'UTC'
  SQL (0.1ms)  SHOW TIME ZONE

NoMethodError (undefined method `rewind' for #<String:0xb711f438>):

--
=========================================
Brandon Casci
Loudcaster
http://loudcaster.com
=========================================

[Brandon Casci]

It does seem like a bug with Rails 3. No explosions with Rails 2.x