aws sns confirm subscription request processing issue

Question

I am trying to implement the aws sns service for a bucket in s3 and i am following this document https://docs.aws.amazon.com/sns/latest/dg/SendMessageToHttp.html according to this there will be subscribe url in the request for the confirmation subscription which will be coming to the url that we provide, but i am receiving empty body in the request. I tried to log the body but gave me an empty object. and tried by using the bodyparser but same result.

here is my route that i am implementing.

 router.post("/s3FileCallback", function (req, res) {
      debugger;
      var bodyParser = require('body-parser');
      var app = express();
      app.use(bodyParser.urlencoded({ extended: false }));
      app.use(bodyParser.json())
      if (req.get("x-amz-sns-message-type") == "SubscriptionConfirmation") {
        console.log("arn" + req.get("x-amz-sns-topic-arn"));
        const subscribeUrl = req.body.SubscribeURL;
        console.log("subscribeUrl" + subscribeUrl);
})

is there any thing i am missing. can any one point me in right direction please.

Answer 1

I found what i was missing,

router.post('/s3FileCallback', function(req, res) {
    debugger;
    if (req.get('x-amz-sns-message-type') == 'SubscriptionConfirmation') {
        console.log('arn' + req.get('x-amz-sns-topic-arn'));
        const subscribeUrl = req.body.SubscribeURL;
        console.log('subscribeUrl' + subscribeUrl);
    }
});

I am using body parser as a middleware, amazon is sending content-type as text\plain in the post request thanks for this forum i did not realize the type until i came across this https://forums.aws.amazon.com/message.jspa?messageID=261061#262098

so tried a work around to change the header before using the bodyparser

app.use(function(req, res, next) {
    if (req.get('x-amz-sns-message-type')) {
        req.headers['content-type'] = 'application/json';
    }
    next();
});
app.use(bodyParser.json({ limit: '50mb' }));
app.use(bodyParser.urlencoded({ limit: '50mb', extended: false }));

so now the req is parsed as json.

Answer 2

In case if you are using php, this should work

$res = file_get_contents('php://input');
file_put_contents('response.txt', $res. "\n", FILE_APPEND);