AWS SNS automatic topic subscription accepter

index.js

const express = require('express')
const request = require('request')
const bodyParser = require('body-parser')

const app = express()
const port = process.env.PORT

app.use(bodyParser.urlencoded({ extended: false }))
app.use(bodyParser.json())

app.post('/*', (req, res) => {
  let body = ''

  req.on('data', (chunk) => {
    body += chunk.toString()
  })

  req.on('end', () => {
    let payload = JSON.parse(body)

    if (payload.Type === 'SubscriptionConfirmation') {
      const promise = new Promise((resolve, reject) => {
        const url = payload.SubscribeURL
        const topic = payload.TopicArn
        const token = payload.Token

        console.log(`Token: ${token} | Topic: ${topic}`)
        console.log(`URL: ${url}`)

        request(url, (error, response) => {
          if (!error && response.statusCode == 200) {
            console.log(`Confirmation accepted from AWS for topic ${topic}`)
            return resolve()
          } else {
            return reject()
          }
        })
      })

      promise.then(() => {
        res.status(200).json({ success: true, path: req.path })
      })
    }
  })
})

app.get('/*', (req, res) => {
  res.status(200).json({ success: true, path: req.path })
})

app.listen(port, () => console.log(`App listening on port ${port}`))