How do I make a http request?

Another extremely common programming task is making an HTTP request to a web server. Node.js provides an extremely simple API for this functionality in the form of http.request.

As an example, we are going to preform a GET request to https://www.random.org/integers/?num=1&min=1&max=10&col=1&base=10&format=plain&rnd=new (which returns a random integer between 1 and 10) and print the result to the console.

var http = require('http');

//The url we want is: 'www.random.org/integers/?num=1&min=1&max=10&col=1&base=10&format=plain&rnd=new'
var options = {
  host: 'www.random.org',
  path: '/integers/?num=1&min=1&max=10&col=1&base=10&format=plain&rnd=new'
};

callback = function(response) {
  var str = '';

  //another chunk of data has been received, so append it to `str`
  response.on('data', function (chunk) {
    str += chunk;
  });

  //the whole response has been received, so we just print it out here
  response.on('end', function () {
    console.log(str);
  });
}

http.request(options, callback).end();

Making a POST request is just as easy. We will make a POST request to www.nodejitsu.com:1337 which is running a server that will echo back what we post. The code for making a POST request is almost identical to making a GET request, just a few simple modifications:

var http = require('http');

//The url we want is `www.nodejitsu.com:1337/`
var options = {
  host: 'www.nodejitsu.com',
  path: '/',
  //since we are listening on a custom port, we need to specify it by hand
  port: '1337',
  //This is what changes the request to a POST request
  method: 'POST'
};

callback = function(response) {
  var str = ''
  response.on('data', function (chunk) {
    str += chunk;
  });

  response.on('end', function () {
    console.log(str);
  });
}

var req = http.request(options, callback);
//This is the data we are posting, it needs to be a string or a buffer
req.write("hello world!");
req.end();

Throwing in custom headers is just a tiny bit harder. On www.nodejitsu.com:1338 we are running a server that will print out the custom header. So we will just make a quick request to it:

var http = require('http');

var options = {
  host: 'www.nodejitsu.com',
  path: '/',
  port: '1338',
  //This is the only line that is new. `headers` is an object with the headers to request
  headers: {'custom': 'Custom Header Demo works'}
};

callback = function(response) {
  var str = ''
  response.on('data', function (chunk) {
    str += chunk;
  });

  response.on('end', function () {
    console.log(str);
  });
}

var req = http.request(options, callback);
req.end();