With custom target ?

gistfile1.txt

var certs = {
		'domain1.com': getCredentialsContext('domain1.com')
};

var options = {
			  ssl: {
				SNICallback: function(hostname){
				  return certs[hostname];
				},
				key: fs.readFileSync('/etc/certs/default.key'),
				cert: fs.readFileSync('/etc/certs/default.crt'),
			  },
			  hostnameOnly: true,
			  target: function(hostname){
				return ips[hostname];
			  },
			  secure: false,
			}

var server = httpProxy.createServer(options);

server.listen(444);