Connecting to remote SSH server (via Node.js/html5 console)

I have been scouring the face of the web looking to answer a question which I had thought would be simple. My goal is straight forward. I want to build out a simple web-based SSH client using Node.js module(s). I have found several options if I want to connect to the node server itself, but can’t seem to find any examples of connecting to a REMOTE server.

Essentially the outcome I am looking for is a workflow like this : Connect to webserver -> Click on a server name in a list of servers -> Enter SSH session to the server I clicked on

The only thing I have found that’s even remotely close to what I am looking for is guacamole. I do not want to use guacamole, however, as I want this application to be OS independent. Currently I am building it on a windows 10 platform, and will port it over to fedora when I am done.

I found this tutorial for creating an SSH terminal. However, all this does is creates (or attempts to create) an SSH connection to the local system.

Another options that looked absolutely fantastic was tty.js. Alas, the bottom-line is the same as the above tutorial. The module only allows you to connect to the node.js server, NOT to remote servers.

Anyone have information on a possible path to this goal?

Answer

This is easily doable with modules like ssh2, xterm, and socket.io.

Here’s an example:

  1. npm install ssh2 xterm socket.io
  2. Create index.html:
<html>
  <head>
    <title>SSH Terminal</title>
    <link rel="stylesheet" href="/src/xterm.css" />
    <script src="/src/xterm.js"></script>
    <script src="/addons/fit/fit.js"></script>
    <script src="/socket.io/socket.io.js"></script>
    <script>
      window.addEventListener('load', function() {
        var terminalContainer = document.getElementById('terminal-container');
        var term = new Terminal({ cursorBlink: true });
        term.open(terminalContainer);
        term.fit();

        var socket = io.connect();
        socket.on('connect', function() {
          term.write('rn*** Connected to backend***rn');

          // Browser -> Backend
          term.on('data', function(data) {
            socket.emit('data', data);
          });

          // Backend -> Browser
          socket.on('data', function(data) {
            term.write(data);
          });

          socket.on('disconnect', function() {
            term.write('rn*** Disconnected from backend***rn');
          });
        });
      }, false);
    </script>
    <style>
      body {
        font-family: helvetica, sans-serif, arial;
        font-size: 1em;
        color: #111;
      }
      h1 {
        text-align: center;
      }
      #terminal-container {
        width: 960px;
        height: 600px;
        margin: 0 auto;
        padding: 2px;
      }
      #terminal-container .terminal {
        background-color: #111;
        color: #fafafa;
        padding: 2px;
      }
      #terminal-container .terminal:focus .terminal-cursor {
        background-color: #fafafa;
      }
    </style>
  </head>
  <body>
    <div id="terminal-container"></div>
  </body>
</html>
  1. Create server.js:
var fs = require('fs');
var path = require('path');
var server = require('http').createServer(onRequest);

var io = require('socket.io')(server);
var SSHClient = require('ssh2').Client;

// Load static files into memory
var staticFiles = {};
var basePath = path.join(require.resolve('xterm'), '..');
[ 'addons/fit/fit.js',
  'src/xterm.css',
  'src/xterm.js'
].forEach(function(f) {
  staticFiles['/' + f] = fs.readFileSync(path.join(basePath, f));
});
staticFiles['/'] = fs.readFileSync('index.html');

// Handle static file serving
function onRequest(req, res) {
  var file;
  if (req.method === 'GET' && (file = staticFiles[req.url])) {
    res.writeHead(200, {
      'Content-Type': 'text/'
                      + (/css$/.test(req.url)
                         ? 'css'
                         : (/js$/.test(req.url) ? 'javascript' : 'html'))
    });
    return res.end(file);
  }
  res.writeHead(404);
  res.end();
}

io.on('connection', function(socket) {
  var conn = new SSHClient();
  conn.on('ready', function() {
    socket.emit('data', 'rn*** SSH CONNECTION ESTABLISHED ***rn');
    conn.shell(function(err, stream) {
      if (err)
        return socket.emit('data', 'rn*** SSH SHELL ERROR: ' + err.message + ' ***rn');
      socket.on('data', function(data) {
        stream.write(data);
      });
      stream.on('data', function(d) {
        socket.emit('data', d.toString('binary'));
      }).on('close', function() {
        conn.end();
      });
    });
  }).on('close', function() {
    socket.emit('data', 'rn*** SSH CONNECTION CLOSED ***rn');
  }).on('error', function(err) {
    socket.emit('data', 'rn*** SSH CONNECTION ERROR: ' + err.message + ' ***rn');
  }).connect({
    host: '192.168.100.105',
    username: 'foo',
    password: 'barbaz'
  });
});

server.listen(8000);
  1. Edit the SSH server configuration passed to .connect() in server.js
  2. node server.js
  3. Visit http://localhost:8000 in your browser

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