index.js

var http = require('http');


if (!process.addAsyncListener) require('async-listener');
// Setup the process's async listener
process.addAsyncListener(setup, {
  before: onBefore
});

var realContext;

var env = {
  get context(){
    return realContext;
  },
  set context(value){
    throw new Error('please use env.createContext to create a new context')
  }
};

var cnt = 0;

env.createContext = function(){
  // INIT CONTEXT
  realContext = {
    '_ctxid': ++cnt
  };
};

// Initialize the null context

// This function is called every time the stack is closing
function setup(){
  return realContext;
}

// This function is called when the new stack starts
function onBefore(_ , context){
  realContext = context;
}


var server = http.createServer(function(req,res){

  env.createContext();

  req.on('data' , function(){
    console.log(env.context);
  });

  req.on('end', function(){
    console.log(env.context);
    res.end('ok');
  });


});


server.listen(3000);