Minimal TCP socket server on Nodejs

tcp.js

const net = require('net');
const server = net.createServer( socket => {
    socket.on('data', (data) => {
        let message = data.toString('utf-8').trim();
        console.log('incoming data ', message);
        if (message === 'exit') {
            let connectionName = socket.address().port + socket.address().address;
            console.log('closing connection to ', connectionName);
            socket.write('exiting...');
            socket.destroy();
        }
    });
});

server.on('connection', socket => {
    let connectionName = socket.address().port + socket.address().address;
    console.log('incoming connection from ', connectionName);

});
const port = process.env.PORT || 8080;
const hostname = process.env.HOSTNAME || 'localhost';
server.listen(port, hostname);