更新一下包
# yum install -y gcc-c++ patch readline readline-devel zlib zlib-devel libyaml-devel libffi-devel openssl-devel make bzip2 autoconf automake libtool bison iconv-devel

安装rvm
# gpg2 --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3
# curl -L get.rvm.io | bash -s stable

查看版本
# rvm -v
# echo "source /etc/profile.d/rvm.sh" >> ~/.bashrc
# su -

更改安装源
sed -i 's/ftp.ruby-lang.org/cache.ruby-lang.org/' /usr/local/rvm/config/

安装
# rvm list know
# rvm install 2.3.0
# rvm use 2.3.0 --default

查看版本
# ruby -v
# gem -v
# gem install sass