Node.js app can't run on port 80 even though there's no other process blocking the port

Question

I'm running an instance of Debian on Amazon EC2 with Node.js installed. If I run the code below:

http = require('http');

http.createServer(function (request, response){
  response.writeHead(200, {'Content-Type':'text/plain'});
  response.end('Hello World\n');
}).listen(80);
console.log("Running server at port 80");

I get the output below which tells me there's another process listening at port 80:

Running server at port 80

events.js:72
        throw er; // Unhandled 'error' event
              ^
Error: listen EACCES
    at errnoException (net.js:901:11)
    at Server._listen2 (net.js:1020:19)
    at listen (net.js:1061:10)
    at Server.listen (net.js:1127:5)
    at Object.<anonymous> (/home/admin/nodetests/nodetest.js:6:4)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Function.Module.runMain (module.js:497:10)

Now when I check to see if there's a process (as root in case anything is hidden) listening on port 80 using:

netstat -tupln

I get the below output, which tells me theres nothing listening at port 80:

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      1667/sshd       
tcp6       0      0 :::22                   :::*                    LISTEN      1667/sshd

I should note that the debian has port 80 open as an inbound rule if that makes a difference.

My question is: What am I doing wrong? How come I can't identify the process listening to port 80? Why is it blocked in Debian? What steps should I take to get the code running correctly?

Answer 1

The error code EACCES means you don't have proper permissions to run applications on that port. On Linux systems, any port below 1024 requires root access.

Answer 2

Instead of running on port 80 you can redirect port 80 to your application's port (>1024) using

iptables -t nat -I PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 3000

This will work if your application is running on port 3000.

Answer 3

Short answer: You can allow node access to that port using:

setcap 'cap_net_bind_service=+ep' /path/to/nodejs

long answer

Edit:

May not work on new node versions

Answer 4

Note that if you have apache running, you can create a reverse proxy on a vhost. If your node is running on port 8080:

<VirtualHost 127.0.0.1:80>
        ServerName myLocalServer

        ProxyPass        /  http://localhost:8080/
        ProxyPassReverse /  http://localhost:8080/
</VirtualHost>

Of course, add server to /etc/hosts:

127.0.0.1    myLocalServer

You will need to enable the relevant apache modules:

sudo a2enmod proxy_html
sudo a2enmod proxy_http
sudo a2enmod proxy_connect
sudo a2enmod proxy_ajp
sudo service apache2 restart

...and now you can connect to http://myLocalServer.