1，安装yum-utils，输入命令：
yum install yum-utils
2，添加nginx源。CentOS8系统自带的nginx源版本是1.14，这里我们自己创建高版本的nginx源，创建文件/etc/yum/repos.d/nginx.repo，命令：
vim /etc/yum.repos.d/nginx.repo。
添加下列内容
[nginx-stable]
name=nginx stable repo
baseurl=http://nginx.org/packages/centos/$releasever/$basearch/
gpgcheck=1
enabled=1
gpgkey=https://nginx.org/keys/nginx_signing.key
module_hotfixes=true
[nginx-mainline]
name=nginx mainline repo
baseurl=http://nginx.org/packages/mainline/centos/$releasever/$basearch/
enabled=0
3、查看nginx源，命令：yum info nginx，nginx源的版本是1.20.1
[root@hecs-76146 ~]# yum info nginx
Last metadata expiration check: 0:05:48 ago on Wed 11 Aug 2021 10:43:41 AM CST.
Installed Packages
Name : nginx
Epoch : 1
Version : 1.20.1
Release : 1.el8.ngx
Architecture : x86_64
Size : 2.8 M
Source : nginx-1.20.1-1.el8.ngx.src.rpm
Repository : @System
From repo : nginx-stable
Summary : High performance web server
URL : https://nginx.org/
License : 2-clause BSD-like license
Description : nginx [engine x] is an HTTP and reverse proxy server, as well as
: a mail proxy server.
4，安装nginx，命令：
yum install nginx