aws sns confirm subscription request processing issue

问题

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.

回答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 cam accross 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.

来源：https://stackoverflow.com/questions/51509836/aws-sns-confirm-subscription-request-processing-issue