using data from JSON in NodeJS

Hello i just started learning Nodejs and made a local server as a start then i saw that most nodejs apps have config and package files i couldnt find any info on how to do a simple one or use JSON files so i tried myself this is what i got so far

this is the server file

var http = require('http');
var json = require('./package');
var fs = require('fs');

var server = http.createServer(function(req, res) {
    res.writeHead(200, {'Content-Type': 'text/plain'});
    res.end('Hello World\n');
}).listen(addr.port);

console.log('server listening at', addr.address + ':' + addr.port);

and this is the json file

{
    "addr": {
        "address":"http://127.0.0.1",
        "port":"8081"
    }
}

i know that it will work with json.address and json.port but when i added "addr" i thought it would simplify things with addr.port

so in short an explanation would be generously accepted on why it wont/shouldnt work or what im doing wrong

via Decapitar