Access node app on digital ocean - This site can't be reached

问题

I am unable to access my digital ocean node js app. I've already SSH'ed in, cloned my Node app from Git, npm installed, and successfully started the app on the droplet, yet I get error

This site can't be reached

Digital Ocean docs say you can access your publicly facing website simply by going to <your website's ip>:<port>:

I did this by going to 67.205.185.63:9000/ (my app is running on port 9000 as you can see):

root@nodejs-512mb-nyc1-01:~/demos# npm start

live-demos@1.0.0 start /root/demos

node app.js

Demos is listening on port 9000

How else should I be accessing my node app?

var express = require('express');
var bodyParser = require('body-parser');

var app = express();
var port = process.env.PORT || 9000;

...

app.listen(port, function () {
    console.log('Demos is listening on port ' + port);
});

回答1:

Some Digital Ocean droplets (mainly one-click apps) come with ufw firewall installed and by default all ports except for 22, 80, and 443 are blocked.

To check if ufw is installed and which ports are blocked/open do:

sudo ufw status

Output:

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

To allow traffic on port 9000 do: