ruby-on-rails – Rails 4：根据环境使用不同的服务器端口

具体而言(开始时很简单)如果环境是生产则在端口3000上运行应用程序,否则在端口3500上运行.

所以,按照这个答案,我在boot.rb文件中添加了以下内容：

require 'rails/commands/server'

module DefaultOptions
  def default_options
    super.merge!(Port: Rails.env.production? ? 3000 : 3500)
  end
end

Rails::Server.send(:prepend,DefaultOptions)

不幸的是我做错了,因为这是我运行rails时的输出：

/home/luca/projects/ads_manager/config/boot.rb:10:in `default_options': undefined method `env' for Rails:Module (NoMethodError)
    from /usr/local/lib/ruby/gems/2.0.0/gems/rack-1.5.2/lib/rack/server.rb:287:in `parse_options'
    from /usr/local/lib/ruby/gems/2.0.0/gems/rack-1.5.2/lib/rack/server.rb:184:in `options'
    from /usr/local/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/commands/server.rb:58:in `set_environment'
    from /usr/local/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/commands/server.rb:42:in `initialize'
    from /usr/local/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/commands.rb:73:in `new'
    from /usr/local/lib/ruby/gems/2.0.0/gems/railties-4.0.0/lib/rails/commands.rb:73:in `<top (required)>'
    from bin/rails:4:in `require'
    from bin/rails:4:in `<main>'

知道为什么Rails.env不可用吗？

获得相同结果的替代方案确实非常受欢迎.