How do you access an Amazon SNS post body with Express / Node.js

Question

I'm in the process of rebuilding a PHP app in Node.js on top of the Express framework.

One part of the application is a callback url that an Amazon SNS notification is posted to.

The POST body from SNS is currently read in the following way in PHP (which works):

$notification = json_decode(file_get_contents('php://input'));

In Express I have tried the following:

app.post('/notification/url', function(req, res) {
    console.log(req.body);
});

However, watching the console, this only logs the following when the post is made:

{}

So, to repeat the question: How do you access an Amazon SNS post body with Express / Node.js

Answer 1

Another approach would be to fix the Content-Type header.

Here is middleware code to do this:

exports.overrideContentType = function(){
  return function(req, res, next) {
    if (req.headers['x-amz-sns-message-type']) {
        req.headers['content-type'] = 'application/json;charset=UTF-8';
    }
    next();
  };
}

This assumes there is a file called util.js located in the root project directory with:

util = require('./util');

in your app.js and invoked by including:

app.use(util.overrideContentType());

BEFORE

app.use(express.bodyParser());

in the app.js file. This allows bodyParser() to parse the body properly...

Less intrusive and you can then access req.body normally.