nginx域名随机跳转到指定域名

# 定义跳转目标域名
map $mod3 $redirect_domain {
    1 "https://b.com";
    2 "https://c.com";
    3 "https://d.com";
}

# 映射变量
map $my_variable $mod3 {
    "~([1-3])" $1;
}

server {
    listen 80;
    server_name a.com;

    location / {
        set $my_variable $request_id;

        if ($mod3) {
            return 302 $redirect_domain$request_uri;
        }
    }
}