非常简单：包括
1。卸载Redhat原有的yum工具：
rpm -aq|grep yum|xargs rpm -e --nodeps　　2。安装CentOS发行版中的yum工具：

wget http://mirrors.163.com/centos/5/os/x86_64/CentOS/yum-3.2.22-26.el5.centos.noarch.rpm
wget http://mirrors.163.com/centos/5/os/x86_64/CentOS/yum-metadata-parser-1.1.2-3.el5.centos.x86_64.rpm
 wget http://mirrors.163.com/centos/5/os/x86_64/CentOS/python-iniparse-0.2.3-4.el5.noarch.rpm
wget http://mirrors.163.com/centos/5/os/x86_64/CentOS/yum-fastestmirror-1.1.16-14.el5.centos.1.noarch.rpm

rpm -ivh python-iniparse-0.2.3-4.el5.noarch.rpm
rpm -ivh yum-*　　3。更新库文件：

wget http://sudone.com/download/CentOS-Base.repo -O /etc/yum.repos.d/CentOS-Base.repo　　附件CentOS-Base.repo文件下载：CentOS-Base
4。使用

yum install httpd　　5。扩展CentOS官方rpm资源
A.添加rpmforge支持：

wget http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.1-1.el5.rf.x86_64.rpm

rpm -ivh rpmforge-release-0.5.1-1.el5.rf.x86_64.rpm　　通过扩展rpmforge，我们之间使用yum安装rrdtool等CentOS官方没有的rpm包。

B.使用epel支持：

wget http://download.fedora.redhat.com/pub/epel/5/x86_64/epel-release-5-4.noarch.rpm

rpm  -ivh epel-release-5-4.noarch.rpm　　通过扩展epel，我们可以使用yum安装puppet工具。