tunnel-ssh

What is tunnel-ssh?

The tunnel-ssh npm package allows you to create SSH tunnels in Node.js applications. This can be useful for securely connecting to remote servers, databases, or other services that require SSH tunneling.

What are tunnel-ssh's main functionalities?

Basic SSH Tunnel

This code sample demonstrates how to set up a basic SSH tunnel using the tunnel-ssh package. The configuration object includes details such as the SSH username, host, port, destination host and port, local host and port, and the private key for authentication.

const tunnel = require('tunnel-ssh');

const config = {
  username: 'user',
  host: 'remote.server.com',
  port: 22,
  dstHost: '127.0.0.1',
  dstPort: 27017,
  localHost: '127.0.0.1',
  localPort: 27017,
  privateKey: require('fs').readFileSync('/path/to/private/key')
};

tunnel(config, function (error, server) {
  if (error) {
    console.error('SSH connection error: ', error);
  } else {
    console.log('SSH tunnel established');
  }
});

SSH Tunnel with Forwarding

This code sample shows how to set up an SSH tunnel with port forwarding. The 'keepAlive' option is set to true to maintain the connection. This is useful for applications that need to keep a persistent connection to a remote database or service.

const tunnel = require('tunnel-ssh');

const config = {
  username: 'user',
  host: 'remote.server.com',
  port: 22,
  dstHost: '127.0.0.1',
  dstPort: 3306,
  localHost: '127.0.0.1',
  localPort: 3306,
  privateKey: require('fs').readFileSync('/path/to/private/key'),
  keepAlive: true
};

tunnel(config, function (error, server) {
  if (error) {
    console.error('SSH connection error: ', error);
  } else {
    console.log('SSH tunnel with forwarding established');
  }
});

Dynamic Port Forwarding

This code sample demonstrates how to set up a dynamic SSH tunnel, which can be used as a SOCKS proxy. The 'dynamic' option is set to true, allowing the tunnel to dynamically forward traffic to different destinations.

const tunnel = require('tunnel-ssh');

const config = {
  username: 'user',
  host: 'remote.server.com',
  port: 22,
  dstHost: '0.0.0.0',
  dstPort: 0,
  localHost: '127.0.0.1',
  localPort: 1080,
  privateKey: require('fs').readFileSync('/path/to/private/key'),
  dynamic: true
};

tunnel(config, function (error, server) {
  if (error) {
    console.error('SSH connection error: ', error);
  } else {
    console.log('Dynamic SSH tunnel established');
  }
});

Other packages similar to tunnel-ssh

ssh2

The ssh2 package is a more general-purpose SSH client for Node.js. It provides a wide range of SSH functionalities, including tunneling, executing commands, and file transfers. Compared to tunnel-ssh, ssh2 offers more flexibility and control over SSH connections but requires more setup and configuration.

node-ssh

The node-ssh package is a high-level SSH client for Node.js that simplifies the process of connecting to SSH servers, executing commands, and transferring files. It is easier to use than ssh2 but offers less control over the SSH connection. It is a good alternative to tunnel-ssh for users who need basic SSH functionalities without the complexity.

ssh2-sftp-client

The ssh2-sftp-client package is built on top of ssh2 and provides a simplified API for SFTP (SSH File Transfer Protocol) operations. While it focuses on file transfers, it can also be used to create SSH tunnels. It is a good choice for users who primarily need SFTP capabilities with occasional SSH tunneling.

README

Tunnel-SSH

Tunnel-ssh is based on the fantastic ssh2 library by Brian White. Trouble ? Please study the ssh2 configuration.

v2.0.0 Released ! We're happy to introduce "reverse Tunnel"

Howto

Pro tip: If you plan to expose a local port on a remote machine you need to enable the "GatewayPorts" option in your 'sshd_config'

# What ports, IPs and protocols we listen for
Port 22
GatewayPorts yes

####map remote port to localhost:

    var tunnel = require('tunnel-ssh');
    //map port from remote 3306 to localhost 3306
    var server = tunnel({host: '172.16.0.8', dstPort: 3306}, function (error, result) {
        //you can start using your resources here. (mongodb, mysql, ....)
        console.log('connected');
    });

####remap remote port to localhost

    // add a localPort for more more control
    var config = {
        host: '172.16.0.8',
        username: 'root',
        dstPort: 3306,
        localPort: 3000
    };
    
    var server = tunnel(config, function (error, result) {
        console.log('connected');
    });

You can find more examples here

tunnel-ssh supports the default ssh2 configuration.

// Or use a full blown ssh2 config, to fit your needs..
{
    username: 'root',
    port: 22,
    srcPort: 0,
    srcHost: 'localhost',
    dstPort: null,
    dstHost: 'localhost',
    localHost: 'localhost'
    agent : process.env.SSH_AUTH_SOCK,
    privateKey:require('fs').readFileSync('/here/is/my/key'),
    password:'secret'
}