配置Nginx监听多个端口

Question

我正在尝试创建多个应用程序，在具有一个 IP 地址（没有域名、子域）的一台服务器上监听不同的端口。

应用程序A监听80端口，
应用程序B监听8080端口

我想通过
http//xxx.xxx.xxx.xxx:80和分别访问两个应用程序http//xxx.xxx.xxx.xxx:8080

如果我有域名，我可以创建多个子域，并像这样配置 nginx：

server {
    server_name A.domain.com;
    listen 80;
    root someplace/;
    try_files /maintenance.html $uri $uri.html @puma;
    location / {
        proxy_set_header  X-Real-IP  $remote_addr;
        proxy_set_header Host $http_host; 
        proxy_set_header Client-IP $remote_addr;
        proxy_set_header X-Forwarded-For $remote_addr;               
        proxy_pass http//xxx.xxx.xxx.xxx:80;
    }
}

server {
    server_name B.domain.com;
    listen 80;
    root someplace/;
    try_files /maintenance.html $uri $uri.html @puma;
    location / {
        proxy_set_header  X-Real-IP  $remote_addr;
        proxy_set_header Host $http_host; 
        proxy_set_header Client-IP $remote_addr;
        proxy_set_header X-Forwarded-For $remote_addr;               
        proxy_pass http//xxx.xxx.xxx.xxx:8080;
    }
}

如果我没有域名，是否可以
http//xxx.xxx.xxx.xxx:80通过http//xxx.xxx.xxx.xxx:8080

像这样吗？

server {
    server_name xxx.xxx.xxx.xxx;
    listen 80;
    root someplace/;
    try_files /maintenance.html $uri $uri.html @puma;
    location / {
        proxy_set_header  X-Real-IP  $remote_addr;
        proxy_set_header Host $http_host; 
        proxy_set_header Client-IP $remote_addr;
        proxy_set_header X-Forwarded-For $remote_addr;               
        proxy_pass http//xxx.xxx.xxx.xxx:80;
    }
}
server {
    server_name xxx.xxx.xxx.xxx;
    listen 8080;
    root someplace/;
    try_files /maintenance.html $uri $uri.html @puma;
    location / {
        proxy_set_header  X-Real-IP  $remote_addr;
        proxy_set_header Host $http_host; 
        proxy_set_header Client-IP $remote_addr;
        proxy_set_header X-Forwarded-For $remote_addr;               
        proxy_pass http//xxx.xxx.xxx.xxx:8080;
    }
}