Node.js不接受端口80上的连接

Question

我正在使用sudo node index.js在ubuntu上运行我的节点服务器 运行curl http://localhost/health-check会给出响应，但如果我使用公共IP，则不会得到任何响应

正在运行sudo netstat -ntlp

Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       
PID/Program name
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      
59739/node

正在运行nmap -A -T4 myDomainName

Starting Nmap 7.01 ( https://nmap.org ) at 2017-11-22 12:32 UTC
Nmap scan report for myDomainName (IP address)
Host is up (0.0011s latency).
Not shown: 997 filtered ports
PORT    STATE  SERVICE VERSION
...
80/tcp  closed http
443/tcp closed https

正在运行nmap localhost

Starting Nmap 7.01 ( https://nmap.org ) at 2017-11-22 12:28 UTC
Nmap scan report for localhost (127.0.0.1)
Host is up (0.000062s latency).
Not shown: 997 closed ports
PORT     STATE SERVICE
22/tcp   open  ssh
80/tcp   open  http

最后sudo ufw status

To                         Action      From
--                         ------      ----
22                         ALLOW       Anywhere
80                         ALLOW       Anywhere
443                        ALLOW       Anywhere
80/tcp                     ALLOW       Anywhere
22 (v6)                    ALLOW       Anywhere (v6)
80 (v6)                    ALLOW       Anywhere (v6)
443 (v6)                   ALLOW       Anywhere (v6)
80/tcp (v6)                ALLOW       Anywhere (v6)

端口80在localhost上打开，但未在域名/ public ip

上打开