Stripe Webhook constructEvent method is returning 400 error when pointed to ec2 instance - node.js

Question

I have developed my application in windows OS and integrated Stripe webhook with the help of ngrok. Everything was smooth and I was able to receive the events from webhook. but once I moved it to ec2 instance on AWS Cloud, it is throwing me an error.
Error: (In Stripe Dashboard Webhook Attempts Section)
Webhook Error: The first argument must be of type string or an instance of Buffer, ArrayBuffer, or Array or an Array-like Object. Received undefined
It is strange that have not changed any piece of code and it still works on windows.
Complete Error:
TypeError [ERR_INVALID_ARG_TYPE]: The "key" argument must be of type string or an instance of Buffer, TypedArray, DataView, or KeyObject
. Received undefined
at prepareSecretKey (internal/crypto/keys.js:322:11)
at new Hmac (internal/crypto/hash.js:111:9)
at Object.createHmac (crypto.js:147:10)
at Object._computeSignature (/home/psuser/middleware/node_modules/stripe/lib/Webhooks.js:65:8)
at Object.verifyHeader (/home/psuser/middleware/node_modules/stripe/lib/Webhooks.js:107:36)
at Object.constructEvent (/home/psuser/middleware/node_modules/stripe/lib/Webhooks.js:12:20)
at /home/psuser/middleware/routes/carts.js:210:29
at Layer.handle [as handle_request] (/home/psuser/middleware/node_modules/express/lib/router/layer.js:95:5)
at next (/home/psuser/middleware/node_modules/express/lib/router/route.js:137:13)
at /home/psuser/middleware/node_modules/body-parser/lib/read.js:130:5
at invokeCallback (/home/psuser/middleware/node_modules/raw-body/index.js:224:16)
at done (/home/psuser/middleware/node_modules/raw-body/index.js:213:7)
at IncomingMessage.onEnd (/home/psuser/middleware/node_modules/raw-body/index.js:273:7)
at IncomingMessage.emit (events.js:327:22)
at endReadableNT (_stream_readable.js:1327:12)
at processTicksAndRejections (internal/process/task_queues.js:80:21) {
code: 'ERR_INVALID_ARG_TYPE'
}
The "key" argument must be of type string or an instance of Buffer, TypedArray, DataView, or KeyObject. Received undefined
// End point Code
router.post('/webhook', async (request, response) => {
const sig = request.headers['stripe-signature'];
let event;
try {
event = stripe.webhooks.constructEvent(request.rawBody, sig, process.env.STRIPE_WEBHOOK_SECRET);
}
catch (err) {
console.log(err.message);
return response.status(400).send(`Webhook Error: ${err.message}`);
}
});
// In app.js
app.use(express.json({
// Because Stripe needs the raw body, we compute it but only when hitting the Stripe callback URL.
verify: function (req, res, buf) {
var url = req.originalUrl;
if (url.endsWith('/webhook')) {
req.rawBody = buf.toString()
}
}
}));

Answer 1

You can install micro (npm install micro) which has its buffer method
const { buffer } = require('micro')
in order to create the required type for the request:
const reqBuffer = await buffer(req)
then you can do:
event = stripe.webhooks.constructEvent(reqBuffer, sig, process.env.STRIPE_WEBHOOK_SECRET);
But I think your problem is simply an ENV variable missing in your EC2 server did you export STRIPE_WEBHOOKS_SECRET=secret in your server?