在 CentOS 中使用 yum 直接来安装 Nginx的话会出现如下错误，原因是Nginx这个软件不是 yum源中自带的，所以需要手动来配置添加 Nginx 的 yum 源。

[root@centos-linux ~]# yum install nginx     
已加载插件：fastestmirror                
Loading mirror speeds from cached hostfile   
 * base: ftp.sjtu.edu.cn     
 * extras: ftp.sjtu.edu.cn   
 * updates: ftp.sjtu.edu.cn 
没有可用软件包 nginx。                                                                             
错误：无须任何处理
添加 yum源:
[root@centos-linux ~]# rpm -ivh http://nginx.org/packages/centos/7/noarch/RPMS/nginx-release-centos-7-0.el7.ngx.noarch.rpm
安装 Nginx:
yum install nginx                                                                                 
已加载插件：fastestmirror                                                                                                
nginx                                                                                             | 2.9 kB  00:00:00     
nginx/x86_64/primary_db                                                                           |  34 kB  00:00:02     
Loading mirror speeds from cached hostfile                                                                               
 * base: ftp.sjtu.edu.cn                                                                                                 
 * extras: ftp.sjtu.edu.cn                                                                                               
 * updates: ftp.sjtu.edu.cn                                                                                              
正在解决依赖关系                                                                                                         
--> 正在检查事务                                                                                                         
---> 软件包 nginx.x86_64.1.1.14.0-1.el7_4.ngx 将被 安装                                                                  
--> 解决依赖关系完成                                                                                                     
                                                                                                                         
依赖关系解决                                                                                                             
                                                                                                                         
=========================================================================================================================
 Package                 架构                     版本                                     源                       大小 
=========================================================================================================================
正在安装:                                                                                                                
 nginx                   x86_64                   1:1.14.0-1.el7_4.ngx                     nginx                   750 k 

事务概要
=========================================================================================================================
安装  1 软件包

总下载量：750 k
安装大小：2.6 M
Is this ok [y/d/N]: y6
Is this ok [y/d/N]: y
Downloading packages:
nginx-1.14.0-1.el7_4.ngx.x86_64.rpm                                                               | 750 kB  00:00:41     
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
警告：RPM 数据库已被非 yum 程序修改。
  正在安装    : 1:nginx-1.14.0-1.el7_4.ngx.x86_64                                                                    1/1 
----------------------------------------------------------------------

Thanks for using nginx!

Please find the official documentation for nginx here:
* http://nginx.org/en/docs/

Please subscribe to nginx-announce mailing list to get
the most important news about nginx:
* http://nginx.org/en/support.html

Commercial subscriptions for nginx are available on:
* http://nginx.com/products/

----------------------------------------------------------------------
  验证中      : 1:nginx-1.14.0-1.el7_4.ngx.x86_64                                                                    1/1 

已安装:
  nginx.x86_64 1:1.14.0-1.el7_4.ngx                                                                                      

完毕！
查看Nginx的软件包信息:
[root@centos-linux ~]# rpm -ql nginx
/etc/logrotate.d/nginx
/etc/nginx
/etc/nginx/conf.d
/etc/nginx/conf.d/default.conf
/etc/nginx/fastcgi_params
/etc/nginx/koi-utf
/etc/nginx/koi-win
/etc/nginx/mime.types
/etc/nginx/modules
/etc/nginx/nginx.conf
/etc/nginx/scgi_params
/etc/nginx/uwsgi_params
/etc/nginx/win-utf
/etc/sysconfig/nginx
/etc/sysconfig/nginx-debug
/usr/lib/systemd/system/nginx-debug.service
/usr/lib/systemd/system/nginx.service
/usr/lib64/nginx
/usr/lib64/nginx/modules
/usr/libexec/initscripts/legacy-actions/nginx
/usr/libexec/initscripts/legacy-actions/nginx/check-reload
/usr/libexec/initscripts/legacy-actions/nginx/upgrade
/usr/sbin/nginx
/usr/sbin/nginx-debug
/usr/share/doc/nginx-1.14.0
/usr/share/doc/nginx-1.14.0/COPYRIGHT
/usr/share/man/man8/nginx.8.gz
/usr/share/nginx
/usr/share/nginx/html
/usr/share/nginx/html/50x.html
/usr/share/nginx/html/index.html
/var/cache/nginx
/var/log/nginx
Nginx 的简单操作:

关闭防火墙:

systemctl stop firewalld.service

查看 Nginx版本：

nginx -v

启动 Nginx服务：

systemctl start nginx

停止 Nginx服务：

systemctl stop nginx

重启 Nginx 服务：

systemctl restart nginx

查看 Nginx 服务状态：

[root@centos-linux html]# systemctl status nginx
● nginx.service - nginx - high performance web server
   Loaded: loaded (/usr/lib/systemd/system/nginx.service; disabled; vendor preset: disabled)
   Active: active (running) since 一 2018-05-14 07:04:11 CST; 7min ago
     Docs: http://nginx.org/en/docs/
  Process: 1928 ExecStart=/usr/sbin/nginx -c /etc/nginx/nginx.conf (code=exited, status=0/SUCCESS)
 Main PID: 1929 (nginx)
   CGroup: /system.slice/nginx.service
           ├─1929 nginx: master process /usr/sbin/nginx -c /etc/nginx/nginx.conf
           └─1930 nginx: worker process

5月 14 07:04:10 centos-linux systemd[1]: Starting nginx - high performance web server...
5月 14 07:04:11 centos-linux systemd[1]: Started nginx - high performance web server.