1、实验环境
[root@localhost ~]# cat /etc/redhat-release
CentOS Linux release 7.4.1708 (Core)
2、测试网络环境
服务器必须能够访问互联网，这里用ping www.baidu.com来测试，使用域名不但可以测试网络的连通性，也可以测试域名解析的功能。
[root@localhost ~]# ping www.baidu.com
PING www.a.shifen.com (14.215.177.39) 56(84) bytes of data.
64 bytes from 14.215.177.39 (14.215.177.39): icmp_seq=1 ttl=55 time=21.0 ms
3、安装wget
若Linux系统中未安装wget，需要安装wget。wget是一个非交互的下载工具，参数 y 的作用是当安装过程中需要用户输入yes或no的时候，默认为yes。
yum -y install wget
4、下载阿里云repo文件。
进入repo目录，删除系统自带的repo文件。下载阿里云的repo文件，作为服务器的yum仓库配置文件。
[root@localhost ~]# cd /etc/yum.repos.d/
[root@localhost yum.repos.d]# rm -rf *
[root@localhost yum.repos.d]# wget -O /etc/yum.repos.d/aliyun.repo http://mirrors.aliyun.com/repo/Centos-7.repo
--2020-05-31 00:00:52-- http://mirrors.aliyun.com/repo/Centos-7.repo
Resolving mirrors.aliyun.com (mirrors.aliyun.com)... 218.67.61.95, 218.67.61.32, 61.131.39.13, ...
Connecting to mirrors.aliyun.com (mirrors.aliyun.com)|218.67.61.95|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 2523 (2.5K) [application/octet-stream]
Saving to: ‘/etc/yum.repos.d/aliyun.repo’
100%[====================================================================================>] 2,523 --.-K/s in 0s
2020-05-31 00:00:52 (297 MB/s) - ‘/etc/yum.repos.d/aliyun.repo’ saved [2523/2523]
[root@localhost yum.repos.d]# ls
aliyun.repo
5、清除yum缓存。
[root@localhost yum.repos.d]# yum clean all
6、创建yum缓存。
[root@localhost yum.repos.d]# yum makecache
7、效果测试。
随便安装一个软件测试，这里使用安装httpd测试。
[root@localhost yum.repos.d]# yum -y install httpd
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
* base: mirrors.aliyun.com
* extras: mirrors.aliyun.com
* updates: mirrors.aliyun.com
Resolving Dependencies
--> Running transaction check
---> Package httpd.x86_64 0:2.4.6-93.el7.centos will be installed
--> Processing Dependency: httpd-tools = 2.4.6-93.el7.centos for package: httpd-2.4.6-93.el7.centos.x86_64
--> Processing Dependency: /etc/mime.types for package: httpd-2.4.6-93.el7.centos.x86_64
--> Processing Dependency: libaprutil-1.so.0()(64bit) for package: httpd-2.4.6-93.el7.centos.x86_64
--> Processing Dependency: libapr-1.so.0()(64bit) for package: httpd-2.4.6-93.el7.centos.x86_64
--> Running transaction check
---> Package apr.x86_64 0:1.4.8-5.el7 will be installed
---> Package apr-util.x86_64 0:1.5.2-6.el7 will be installed
---> Package httpd-tools.x86_64 0:2.4.6-93.el7.centos will be installed
---> Package mailcap.noarch 0:2.1.41-2.el7 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
==============================================================================================================================
Package Arch Version Repository Size
==============================================================================================================================
Installing:
httpd x86_64 2.4.6-93.el7.centos base 2.7 M
Installing for dependencies:
apr x86_64 1.4.8-5.el7 base 103 k
apr-util x86_64 1.5.2-6.el7 base 92 k
httpd-tools x86_64 2.4.6-93.el7.centos base 92 k
mailcap noarch 2.1.41-2.el7 base 31 k
Transaction Summary
==============================================================================================================================
Install 1 Package (+4 Dependent packages)
Total download size: 3.0 M
Installed size: 10 M
Downloading packages:
warning: /var/cache/yum/x86_64/7/base/packages/apr-1.4.8-5.el7.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID f4a80eb5: NOKEY
Public key for apr-1.4.8-5.el7.x86_64.rpm is not installed
(1/5): apr-1.4.8-5.el7.x86_64.rpm | 103 kB 00:00:00
(2/5): apr-util-1.5.2-6.el7.x86_64.rpm | 92 kB 00:00:00
(3/5): httpd-tools-2.4.6-93.el7.centos.x86_64.rpm | 92 kB 00:00:00
(4/5): mailcap-2.1.41-2.el7.noarch.rpm | 31 kB 00:00:00
(5/5): httpd-2.4.6-93.el7.centos.x86_64.rpm | 2.7 MB 00:00:00
------------------------------------------------------------------------------------------------------------------------------
Total 4.6 MB/s | 3.0 MB 00:00:00
Retrieving key from http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
Importing GPG key 0xF4A80EB5:
Userid : "CentOS-7 Key (CentOS 7 Official Signing Key) <security@centos.org>"
Fingerprint: 6341 ab27 53d7 8a78 a7c2 7bb1 24c6 a8a7 f4a8 0eb5
From : http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : apr-1.4.8-5.el7.x86_64 1/5
Installing : apr-util-1.5.2-6.el7.x86_64 2/5
Installing : httpd-tools-2.4.6-93.el7.centos.x86_64 3/5
Installing : mailcap-2.1.41-2.el7.noarch 4/5
Installing : httpd-2.4.6-93.el7.centos.x86_64 5/5
Verifying : apr-1.4.8-5.el7.x86_64 1/5
Verifying : httpd-tools-2.4.6-93.el7.centos.x86_64 2/5
Verifying : mailcap-2.1.41-2.el7.noarch 3/5
Verifying : httpd-2.4.6-93.el7.centos.x86_64 4/5
Verifying : apr-util-1.5.2-6.el7.x86_64 5/5
Installed:
httpd.x86_64 0:2.4.6-93.el7.centos
Dependency Installed:
apr.x86_64 0:1.4.8-5.el7 apr-util.x86_64 0:1.5.2-6.el7 httpd-tools.x86_64 0:2.4.6-93.el7.centos
mailcap.noarch 0:2.1.41-2.el7
Complete!
