Syntax:   auth_basic string | off;
Context: http, server, location, limit_except

Syntax:   auth_basic_user_file file;
Context: http, server, location, limit_except

yum install -y httpd-tools

htpasswd -cm /etc/nginx/conf.d/passd user10
New password: 
Re-type new password: 
Adding password for user user10

htpasswd -cm /etc/nginx/conf.d/passwd user20
New password: 
Re-type new password: 
Adding password for user user20

cat /etc/nginx/conf.d/passwd
user20:$apr1$vf7FaD7g$LDp1Ek1Ac6jcZ58jfmrHd.
user10:$apr1$DF.j25Kl$bcg3vfVhIU4wi7aXPuWKa.

vim /etc/nginx/conf.d/default.conf
server {
   auth_basic "nginx access test!"; #提示消息
   auth_basic_user_file /etc/nginx/conf.d/passwd;  #引用认证文件
}