A cron job that invalidates links and creates new ones.

index.js

var express = require("express");

var app = express();

function randomString(length) {
    var result = '';
    var chars = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
    for (var i = length; i > 0; --i) 
        result += chars[Math.floor(Math.random() * chars.length)];
    return result;
}

var cron = require('node-cron');
var rString = randomString(12);
cron.schedule('15,30,45 * * * * *', function(){
    rString = randomString(12);
    console.log("Your random route is: localhost:3000/"+rString);
});

console.log("Your random route is: localhost:3000/"+rString);
app.get("/:randomStr", function(req, res){
    if(req.params.randomStr === rString)
        res.send("Yo!")
    else
        res.send("Sorry no link found!");
});    
app.get("*",function(req,res){
    res.send("Sorry no link found!"); 
});

app.listen(3000);