ERROR connecting to remote database server(NGINX) via tunneled localhost Node JS - node.js

Question

error connecting: Error: Connection lost: The server closed the connection.
at Protocol.end (C:\Users\Tony\Documents\TestServer\node_modules\mysql\lib\protocol\Protocol.js:109:13)
at Socket.<anonymous> (C:\Users\Tony\Documents\TestServer\node_modules\mysql\lib\Connection.js:109:28)
at emitNone (events.js:91:20)
at Socket.emit (events.js:185:7)
at endReadableNT (_stream_readable.js:974:12)
at _combinedTickCallback (internal/process/next_tick.js:74:11)
at process._tickCallback (internal/process/next_tick.js:98:9)
--------------------
at Protocol._enqueue (C:\Users\Tony\Documents\TestServer\node_modules\mysql\lib\protocol\Protocol.js:141:48)
at Protocol.handshake (C:\Users\Tony\Documents\TestServer\node_modules\mysql\lib\protocol\Protocol.js:52:41)
at Connection.connect (C:\Users\Tony\Documents\TestServer\node_modules\mysql\lib\Connection.js:130:18)
at Object.<anonymous> (C:\Users\Tony\Documents\TestServer\app.js:13:12)
at Module._compile (module.js:570:32)
at Object.Module._extensions..js (module.js:579:10)
at Module.load (module.js:487:32)
at tryModuleLoad (module.js:446:12)
at Function.Module._load (module.js:438:3)
at Module.runMain (module.js:604:10)
using this code
var express = require('express');
var mysql = require('mysql');
var connection = mysql.createConnection({
host: 'localhost',
port: '8888',
user: 'root',
password: 'xxx',
database: 'shop'
});
connection.connect(function(err) {
if (err) {
console.error('error connecting: ' + err.stack);
return;
}
console.log('connected as id ' + connection.threadId);
});
server is BITNAMI using google cloud
localhost is on windows, i can connect to the phpmyadmin through the browser but the script does not work. Thank you

Answer 1

Hi Bitnami developer here,
As you mentioned, you can access phpMyAdmin using the 8888 port because you opened a tunnel to access Apache and that application through that port. You would need to open a new tunnel to access MySQL directly because we configure the server to only listen to localhost for security reasons.
The source port of this new tunnel would be a different port (i.e 8989) and the destination would be localhost:3306 (3306 is the MySQL default port). You would need to modify your code to use the 8989 port instead of the 8888 one.
I hope this information helps.
Jota

Answer 2

To find out if the tunnel is really set up you can run.
sudo lsof -i -n | egrep '\<ssh\>'
you should get some lines out of that. If one of them is around these lines :
ssh 11704 root 3u IPv4 47283826 0t0 TCP [localip]:46286->[remoteip]:ssh (ESTABLISHED)
then the connection is on. In this case you should make sure you are connecting your nodejs application to the correct local port. The code above seems correct just make sure that the tunnel is then from port :8888 to the remote database port, maybe :3607 or whatever the port is.
Otherwise, if your tunnel is not set up properly. There are quite a few tutorials out there explaining how to set an ssh tunnel such as this one :
https://support.cloud.engineyard.com/hc/en-us/articles/205408088-Access-Your-Database-Remotely-Through-an-SSH-Tunnel
Make sure that you also use autossh to set up the tunnel. SSH tunnels are unstable and they tend to fall. Autossh will make sure that the connection is brought back up and that is run when the computer boots up.
https://www.everythingcli.org/ssh-tunnelling-for-fun-and-profit-autossh/