index.js

const express = require('express');
const cookieParser = require('cookie-parser');
const app = express();
app.use(cookieParser());

app.get('/', function (req, res) {
    if (req.cookies.default) {
        console.log('Received cookie from instance');
        res.send('123').status('200');
    } else {
        console.log('No cookie, sending.');
        res.cookie('default', '123', { maxAge: 90000, httpOnly: true }).send('123').status('200');
    }
});

app.listen(3000);