Question

我已将我的应用程序部署到Heroku并分配环境以创建一个＆＃39; staging＆＃39;环境。我复制了我的paroduction.rb文件以创建staging.rb，但是当我将RAILS_ENV和RACK_ENV变量从生产更改为暂存时，不会返回任何资产，并且日志显示以下类型错误：

2014-05-05T07:42:33.614170+00:00 app[web.1]: F, [2014-05-05T07:42:33.610206 #2] FATAL -- :
2014-05-05T07:42:33.614172+00:00 app[web.1]: ActionController::RoutingError (No route matches [GET] "/assets/application-835271b3bd7cf8b176e8b30d9ca395fd.js"):
2014-05-05T07:42:33.614173+00:00 app[web.1]:   vendor/bundle/ruby/2.0.0/gems/actionpack-4.0.4/lib/action_dispatch/middleware/debug_exceptions.rb:21:in `call'
2014-05-05T07:42:33.614174+00:00 app[web.1]:   vendor/bundle/ruby/2.0.0/gems/actionpack-4.0.4/lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
2014-05-05T07:42:33.614176+00:00 app[web.1]:   vendor/bundle/ruby/2.0.0/gems/railties-4.0.4/lib/rails/rack/logger.rb:38:in `call_app'
2014-05-05T07:42:33.614177+00:00 app[web.1]:   vendor/bundle/ruby/2.0.0/gems/railties-4.0.4/lib/rails/rack/logger.rb:20:in `block in call'
2014-05-05T07:42:33.614178+00:00 app[web.1]:   vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.4/lib/active_support/tagged_logging.rb:68:in `block in tagged'
2014-05-05T07:42:33.614200+00:00 app[web.1]:   vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.4/lib/active_support/tagged_logging.rb:26:in `tagged'
2014-05-05T07:42:33.614202+00:00 app[web.1]:   vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.4/lib/active_support/tagged_logging.rb:68:in `tagged'
2014-05-05T07:42:33.614203+00:00 app[web.1]:   vendor/bundle/ruby/2.0.0/gems/railties-4.0.4/lib/rails/rack/logger.rb:20:in `call'
2014-05-05T07:42:33.614204+00:00 app[web.1]:   vendor/bundle/ruby/2.0.0/gems/actionpack-4.0.4/lib/action_dispatch/middleware/request_id.rb:21:in `call'
2014-05-05T07:42:33.614206+00:00 app[web.1]:   vendor/bundle/ruby/2.0.0/gems/rack-1.5.2/lib/rack/methodoverride.rb:21:in `call'
2014-05-05T07:42:33.614207+00:00 app[web.1]:   vendor/bundle/ruby/2.0.0/gems/rack-1.5.2/lib/rack/runtime.rb:17:in `call'
2014-05-05T07:42:33.614218+00:00 app[web.1]:   vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.4/lib/active_support/cache/strategy/local_cache.rb:83:in `call'
2014-05-05T07:42:33.614219+00:00 app[web.1]:   vendor/bundle/ruby/2.0.0/gems/rack-1.5.2/lib/rack/sendfile.rb:112:in `call'
2014-05-05T07:42:33.614221+00:00 app[web.1]:   vendor/bundle/ruby/2.0.0/gems/railties-4.0.4/lib/rails/engine.rb:511:in `call'
2014-05-05T07:42:33.614222+00:00 app[web.1]:   vendor/bundle/ruby/2.0.0/gems/railties-4.0.4/lib/rails/application.rb:97:in `call'
2014-05-05T07:42:33.614224+00:00 app[web.1]:   vendor/bundle/ruby/2.0.0/gems/rack-1.5.2/lib/rack/lock.rb:17:in `call'
2014-05-05T07:42:33.614225+00:00 app[web.1]:   vendor/bundle/ruby/2.0.0/gems/rack-1.5.2/lib/rack/content_length.rb:14:in `call'
2014-05-05T07:42:33.614226+00:00 app[web.1]:   vendor/bundle/ruby/2.0.0/gems/rack-1.5.2/lib/rack/handler/webrick.rb:60:in `service'
2014-05-05T07:42:33.614228+00:00 app[web.1]:   vendor/ruby-2.0.0/lib/ruby/2.0.0/webrick/httpserver.rb:138:in `service'
2014-05-05T07:42:33.614229+00:00 app[web.1]:   vendor/ruby-2.0.0/lib/ruby/2.0.0/webrick/httpserver.rb:94:in `run'
2014-05-05T07:42:33.614231+00:00 app[web.1]:   vendor/ruby-2.0.0/lib/ruby/2.0.0/webrick/server.rb:295:in `block in start_thread'

我在Stackoverflow上找到了其他帖子，例如：ActionController::RoutingError (No route matches [GET] "/assets/images/control_top.png"): in rails 3.2.8

确实将config.serve_static_assets = false更改为true解决了问题，但我不愿意在我的暂存环境中执行此操作，并且我了解这会影响生产环境中的性能。

我真正不明白的是，为什么会出现这种错误，因为据我所知，唯一的区别是环境变量名称已更改。所以对我的问题：

更改这些环境变量实际上会对应用程序产生什么影响？为什么它在我的应用程序中有这种效果？

作为奖励，如果有更好的方法来解决我已经描述过的基础问题，我会很感激指导。

Answer 1

进一步调查已经确定环境变量的设置在部署中具有以下效果：

特定于环境的配置文件（例如config/environments/production.rb）
安装Gemfile组中定义的gem（例如group :production）

在这种情况下，heroku需要gem 'rails_12factor'来启用静态资产。因此除group :production :staging之外，{{1}}还需要此宝石。

改变RACK_ENV和RAILS_ENV有什么作用？

1 个答案: