responseInterceptor does not modify response

[ortonomy]

Check this code - I'm trying to replace the host in an M3U playlist response (original address is http://10.0.0.1/PRIVATE_HLS.m3u

but I'm local forwarding SSH 0.0.0.0:8081 -> 80 and 0.0.00:9091->9091

• output from console.log(modifiedResponse) logs desired replaced response
• response received from cURL request is completely unmodified response.

Can you help?

Curl response headers:

HTTP/1.1 200 OK
Accept-Ranges: bytes
Connection: Keep-Alive
Content-Length: 8558
Content-Type: audio/mpegurl
Date: Sat, 31 Aug 2024 15:31:23 GMT
Date: Sat, 31 Aug 2024 15:31:23 GMT
ETag: "216e-618cb07f294d5"
Keep-Alive: timeout=5, max=100
Last-Modified: Sun, 19 May 2024 09:15:51 GMT
X-Powered-By: Express
server: Apache/2.4.52 (Ubuntu)

code:

import express from 'express'
import {
  createProxyMiddleware,
  responseInterceptor,
} from 'http-proxy-middleware'
import buffer from 'buffer'

const app = express()
const host = '0.0.0.0'
const port = 8080

const connectionString = `${host}:${port}`

app.use(
  '/',
  createProxyMiddleware({
    target: 'http://localhost:8081',
    changeOrigin: false,
    selfHandleREsponse: true,
    on: {
      proxyRes: responseInterceptor(
        (responseBuffer, proxyRes, req, res) => {
          console.log('Intercepting response')
          const response = responseBuffer.toString('utf8') // convert buffer to string
          const modifiedResponse = response.replaceAll('10.0.0.1', '192.168.0.99')
          console.log(modifiedResponse)
          return modifiedResponse
        }
      ),
      error: (err, req, res) => {
        console.error('Proxy error:', err)
        res.writeHead(500, {
          'Content-Type': 'text/plain',
        })
        res.end(
          'Something went wrong. And we are reporting a custom error message.'
        )
      },
    },
  })
)

app.listen(port, host, () => {
  console.log(`Proxy server listening on ${connectionString}`)
})

[chimurai]

Looks like you forgot the async

      proxyRes: responseInterceptor(
        async (responseBuffer, proxyRes, req, res) => {

Documentation/Example:
https://github.com/chimurai/http-proxy-middleware/blob/master/recipes/response-interceptor.md#replace-text-and-change-http-status-code