安装ruby
sudo yum install ruby ruby-devel
ruby -v
#ruby 2.0.0p353 (2013-11-22 revision 43784) [i386-linux]
更新gem
sudo gem update --system
gem -v
#2.4.1
安装rails
gem install rails --no-ri --no-rdoc
#27 gems installed
rails -v
#Rails 4.1.6
新建项目
rails new app/dir
cd app/dir
rails server