在CentOS上安装第三方软件库EPEL

Extra Packages for Enterprise Linux (EPEL)【企业版 Linux 附加软件包(以下简称 EPEL)】是一个由特别兴趣小组创建、维护并管理的，针对 红帽企业版 Linux(RHEL)及其衍生发行版(比如 CentOS、 Scientific Linux)的一个高质量附加软件包项目。
EPEL 的软件包通常不会与企业版Linux官方源中的软件包发生冲突，或者互相替换文件。EPEL与Fedora项目基本一致，包含完整的构建系统、升级管理器、镜像管理器等等。
EPEL 包含一个叫做epel-release的包，这个包包含了EPEL源的gpg密钥和软件源信息。您可以通过yum安装到您的企业版Linux发行版上。除了epel-release源，还有一个叫做epel-testing的源，这个源包含最新的测试软件包，其版本很新但是安装有风险，请自行斟酌。
注意: 有些第三方软件源需要 EPEL 的'epel-testing'源来安装依赖组件，请务必在系统设置中启用本源。 这里 有相关的开启教程。(相关配置文件位于：/etc/yum.repos.d/epel-testing.repo)。

1.首先检查系统是否安装epel-release

[root@localhost ~]
# rpm -q epel-release
package epel-release is not installed

2.安装EPEL

[root@localhost ~]# rpm -ivh http://mirrors.ustc.edu.cn/fedora/epel/6/x86_64/epel-release-6-8.noarch.rpm
Retrieving http://mirrors.ustc.edu.cn/fedora/epel/6/x86_64/epel-release-6-8.noarch.rpm
Preparing...                ########################################### [100%]
   1:epel-release           ########################################### [100%]

注意：
1、要安装最新版本的EPEL，请前往 http://mirrors.ustc.edu.cn/fedora/epel/ 中查找最新版本的URL地址，这里采用的是6.8版本
32位：http://mirrors.ustc.edu.cn/fedora/epel/6/i386/epel-release-6-8.noarch.rpm
64位：http://mirrors.ustc.edu.cn/fedora/epel/6/x86_64/epel-release-6-8.noarch.rpm

2、若出现下面类似错误，则表示对应的URL已经不存在，需要重新找EPEL的版本，请前往 http://mirrors.ustc.edu.cn/fedora/epel/ 获取需要的版本

[root@localhost ~]# rpm -ivh http://mirrors.ustc.edu.cn/fedora/epel/6/x86_64/epel-release-6-8.noarch.rpm
Retrieving http://mirrors.ustc.edu.cn/fedora/epel/6/x86_64/epel-release-6-8.noarch.rpm
curl: (22) The requested URL returned error: 404 Not Found
error: skipping http://mirrors.ustc.edu.cn/fedora/epel/6/x86_64/epel-release-6-8.noarch.rpm - transfer failed

#2.1 安装成功

[root@localhost ~]# rpm -q epel-release
epel-release-6-8.noarch

#2.2 查看其所依附的软件文件

[root@localhost ~]# rpm -qR epel-release  
/bin/sh  
/bin/sh  
config(epel-release) = 6-8
redhat-release >= 6
rpmlib(CompressedFileNames) <= 3.0.4-1
rpmlib(FileDigests) <= 4.6.0-1
rpmlib(PayloadFilesHavePrefix) <= 4.0-1
rpmlib(PayloadIsXz) <= 5.2-1

#2.3 卸载

[root@localhost ~]# rpm -e epel-release
warning: /etc/yum.repos.d/epel.repo saved as /etc/yum.repos.d/epel.repo.rpmsave

#2.4 设置源级别

[root@localhost ~]# vi /etc/yum.repos.d/epel.repo
设置 /etc/yum.repos.d/epel.repo 中源的级别为 priority=11

#2.5 搜索软件包
若要查看 EPEL Repo 中是否存在某个软件包：yum search package-name，若搜索git

[root@localhost ~]# yum search git
Loaded plugins: fastestmirror, refresh-packagekit, security
Loading mirror speeds from cached hostfile
 * base: mirrors.aliyun.com
 * epel: mirrors.hust.edu.cn
 * extras: mirrors.aliyun.com
 * updates: mirror.bit.edu.cn
============================== N/S Matched: git ===============================
nodejs-github-url-from-git.noarch : Parse a GitHub git URL and return the GitHub repository URL
php-phpunit-git.noarch : Simple wrapper for Git
trac-git-plugin.noarch : GIT version control plugin for Trac
GitPython.noarch : Python Git Library
cgit.x86_64 : A fast web interface for git
git-annex.x86_64 : Manage files with git, without checking their contents into git
git-ftp.noarch : Git powered FTP client written as shell script
git-gui.noarch : Git GUI tool
git-review.noarch : A git helper for integration with Gerrit
git2cl.noarch : Converts git logs to GNU style ChangeLog format
gitolite.noarch : Highly flexible server for git directory version tracker
gitosis.noarch : Git repository hosting application
gitstats.noarch : Generates statistics based on GIT repository activity
// ……（略）
tkgate-fr.x86_64 : Locales and examples for tkgate, Digital Circuit Simulator
tkgate-it.x86_64 : Locales and examples for tkgate, Digital Circuit Simulator
tkgate-ja.x86_64 : Locales and examples for tkgate, Digital Circuit Simulator
tuxpaint.x86_64 : Drawing program designed for young children
xmlsec1-devel.i686 : Libraries, includes, etc. to develop applications with XML Digital
                   : Signatures and XML Encryption support.
xmlsec1-devel.x86_64 : Libraries, includes, etc. to develop applications with XML Digital
                     : Signatures and XML Encryption support.

  Name and summary matches only, use "search all" for everything.

3. 安装第三方软件
使用yum install package-name命令安装第三方软件，如使用yum install git安装git

[root@localhost ~]# yum install git
Loaded plugins: fastestmirror, refresh-packagekit, security
Loading mirror speeds from cached hostfile
epel/metalink                                                 | 5.5 kB     00:00     
 * base: mirrors.aliyun.com
 * epel: ftp.sjtu.edu.cn
 * extras: mirrors.aliyun.com
 * updates: mirror.bit.edu.cn
epel                                                          | 4.4 kB     00:00     
epel/primary_db                                               | 6.0 MB     01:19     
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package git.x86_64 0:1.7.1-3.el6_4.1 will be installed
--> Processing Dependency: perl-Git = 1.7.1-3.el6_4.1 for package: git-1.7.1-3.el6_4.1.x86_64
--> Processing Dependency: perl(Git) for package: git-1.7.1-3.el6_4.1.x86_64
--> Processing Dependency: perl(Error) for package: git-1.7.1-3.el6_4.1.x86_64
--> Running transaction check
---> Package perl-Error.noarch 1:0.17015-4.el6 will be installed
---> Package perl-Git.noarch 0:1.7.1-3.el6_4.1 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

==================================================================================
 Package                Arch       Version                 Repository        Size
==================================================================================
Installing:
 git                    x86_64     1.7.1-3.el6_4.1         base             4.6 M
Installing for dependencies:
 perl-Error             noarch     1:0.17015-4.el6         base              29 k
 perl-Git               noarch     1.7.1-3.el6_4.1         base              28 k

Transaction Summary
==================================================================================
Install       3 Package(s)

Total download size: 4.7 M
Installed size: 15 M
Is this ok [y/N]: y
Downloading Packages:
(1/3): git-1.7.1-3.el6_4.1.x86_64.rpm                         | 4.6 MB     00:33     
(2/3): perl-Error-0.17015-4.el6.noarch.rpm                    |  29 kB     00:00     
(3/3): perl-Git-1.7.1-3.el6_4.1.noarch.rpm                    |  28 kB     00:00     
----------------------------------------------------------------------------------
Total                                                          140 kB/s | 4.7 MB     00:34     
warning: rpmts_HdrFromFdno: Header V3 RSA/SHA1 Signature, key ID c105b9de: NOKEY
Retrieving key from file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6
Importing GPG key 0xC105B9DE:
 Userid : CentOS-6 Key (CentOS 6 Official Signing Key) <[e-mail]>
 Package: centos-release-6-4.el6.centos.10.x86_64 (@anaconda-CentOS-201303020151.x86_64/6.4)
 From   : /etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6
Is this ok [y/N]: y    （注：这里为输入的内容，导入GPG key）
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
Warning: RPMDB altered outside of yum.
  Installing : 1:perl-Error-0.17015-4.el6.noarch                             1/3 
  Installing : perl-Git-1.7.1-3.el6_4.1.noarch                               2/3 
  Installing : git-1.7.1-3.el6_4.1.x86_64                                    3/3 
  Verifying  : git-1.7.1-3.el6_4.1.x86_64                                    1/3 
  Verifying  : perl-Git-1.7.1-3.el6_4.1.noarch                               2/3 
  Verifying  : 1:perl-Error-0.17015-4.el6.noarch                             3/3 

Installed:
  git.x86_64 0:1.7.1-3.el6_4.1                                                                 

Dependency Installed:
  perl-Error.noarch 1:0.17015-4.el6              perl-Git.noarch 0:1.7.1-3.el6_4.1             

Complete!

4. 参考资料
[1]EPEL
https://fedoraproject.org/wiki/EPEL
[2]CentOS 6.2安装第三方软件库epel
http://blog.csdn.net/jackalfly/article/details/7572886