我正在尝试使用 rails-api gem rails-api和couchrest model设置 rails API 。使用 rails-api 去除了很多中间件和模块，我相信这就是我收到以下错误的原因：
Started GET "/assets" for 127.0.0.1 at 2012-10-10 16:00:36 +0100
Connecting to database specified by database.yml
ActiveRecord::ConnectionNotEstablished (ActiveRecord::ConnectionNotEstablished):
activerecord (3.2.8) lib/active_record/connection_adapters/abstract/connection_pool.rb:404:in `retrieve_connection'
activerecord (3.2.8) lib/active_record/connection_adapters/abstract/connection_specification.rb:170:in `retrieve_connection'
activerecord (3.2.8) lib/active_record/connection_adapters/abstract/connection_specification.rb:144:in `connection'
activerecord (3.2.8) lib/active_record/query_cache.rb:67:in `rescue in call'
activerecord (3.2.8) lib/active_record/query_cache.rb:61:in `call'
activerecord (3.2.8) lib/active_record/connection_adapters/abstract/connection_pool.rb:473:in `call'
actionpack (3.2.8) lib/action_dispatch/middleware/callbacks.rb:28:in `block in call'
activesupport (3.2.8) lib/active_support/callbacks.rb:405:in `_run__2405051170962911444__call__2117088860059348020__callbacks'
activesupport (3.2.8) lib/active_support/callbacks.rb:405:in `__run_callback'
activesupport (3.2.8) lib/active_support/callbacks.rb:385:in `_run_call_callbacks'
activesupport (3.2.8) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (3.2.8) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (3.2.8) lib/action_dispatch/middleware/reloader.rb:65:in `call'
actionpack (3.2.8) lib/action_dispatch/middleware/remote_ip.rb:31:in `call'
actionpack (3.2.8) lib/action_dispatch/middleware/debug_exceptions.rb:16:in `call'
actionpack (3.2.8) lib/action_dispatch/middleware/show_exceptions.rb:56:in `call'
railties (3.2.8) lib/rails/rack/logger.rb:26:in `call_app'
railties (3.2.8) lib/rails/rack/logger.rb:16:in `call'
actionpack (3.2.8) lib/action_dispatch/middleware/request_id.rb:22:in `call'
rack (1.4.1) lib/rack/runtime.rb:17:in `call'
activesupport (3.2.8) lib/active_support/cache/strategy/local_cache.rb:72:in `call'
rack (1.4.1) lib/rack/lock.rb:15:in `call'
actionpack (3.2.8) lib/action_dispatch/middleware/static.rb:62:in `call'
railties (3.2.8) lib/rails/engine.rb:479:in `call'
railties (3.2.8) lib/rails/application.rb:223:in `call'
rack (1.4.1) lib/rack/content_length.rb:14:in `call'
railties (3.2.8) lib/rails/rack/log_tailer.rb:17:in `call'
rack (1.4.1) lib/rack/handler/webrick.rb:59:in `service'
/Users/jason/.rvm/rubies/ruby-1.9.2-p320/lib/ruby/1.9.1/webrick/httpserver.rb:111:in `service'
/Users/jason/.rvm/rubies/ruby-1.9.2-p320/lib/ruby/1.9.1/webrick/httpserver.rb:70:in `run'
/Users/jason/.rvm/rubies/ruby-1.9.2-p320/lib/ruby/1.9.1/webrick/server.rb:183:in `block in start_thread'
Rendered /Users/jason/.rvm/gems/ruby-1.9.2-p320/gems/actionpack-3.2.8/lib/action_dispatch/middleware/templates/rescues/_trace.erb (0.9ms)
Rendered /Users/jason/.rvm/gems/ruby-1.9.2-p320/gems/actionpack-3.2.8/lib/action_dispatch/middleware/templates/rescues/_request_and_response.erb (1.9ms)
Rendered /Users/jason/.rvm/gems/ruby-1.9.2-p320/gems/actionpack-3.2.8/lib/action_dispatch/middleware/templates/rescues/diagnostics.erb within rescues/layout (8.1ms)
谁能指出我需要包含哪些模块和中间件才能使其正常工作？谢谢