write EPIPE error while proxying Websocket requests

[boomdizz]

Version

v16.15.1

Platform

Linux xxxxx-HP-EliteBook-840-G3 5.13.0-44-generic #49~20.04.1-Ubuntu SMP Wed May 18 18:44:28 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux

Subsystem

No response

What steps will reproduce the bug?

Running node as a development server with a proxy.conf.js file that looks like:

const PROXY_CONFIG = {
    "/graphql" : {
        target: "https://localhost:443/graphql",
        router:  function(req) {
            return "https://localhost:443/graphql"
        },
        changeOrigin: true,
        secure: false,
        logLevel: "debug",
        ws: true
    }
};

module.exports = PROXY_CONFIG;

Proxying graphql calls (queries, mutations and subscriptions through websockets) from an Angular application using an Apollo client.

The Proxy was working well with an earlier version of node, but post upgrade to 16.15.1 (LTS), I get this error on starting ng serve:

✔ Compiled successfully.
[HPM] Router new target: https://localhost:443/graphql -> "https://localhost:443/graphql"
[HPM] GET /graphql/ -> https://localhost:443/graphql
[HPM] Upgrading to WebSocket
[HPM] Router new target: https://localhost:443/graphql -> "https://localhost:443/graphql"
[HPM] GET /graphql/ -> https://localhost:443/graphql
[HPM] Upgrading to WebSocket
[HPM] Router new target: https://localhost:443/graphql -> "https://localhost:443/graphql"
[HPM] GET /graphql/ -> https://localhost:443/graphql
[HPM] Upgrading to WebSocket
[HPM] Router new target: https://localhost:443/graphql -> "https://localhost:443/graphql"
[HPM] GET /graphql/ -> https://localhost:443/graphql
[HPM] Upgrading to WebSocket
node:events:505
      throw er; // Unhandled 'error' event
      ^

Error: write EPIPE
    at afterWriteDispatched (node:internal/stream_base_commons:160:15)
    at writeGeneric (node:internal/stream_base_commons:151:3)
    at Socket._writeGeneric (node:net:817:11)
    at Socket._write (node:net:829:8)
    at writeOrBuffer (node:internal/streams/writable:389:12)
    at _write (node:internal/streams/writable:330:10)
    at Socket.Writable.write (node:internal/streams/writable:334:10)
    at IncomingMessage.ondata (node:internal/streams/readable:754:22)
    at IncomingMessage.emit (node:events:527:28)
    at IncomingMessage.Readable.read (node:internal/streams/readable:527:10)
Emitted 'error' event on Socket instance at:
    at Socket.onerror (node:internal/streams/readable:773:14)
    at Socket.emit (node:events:527:28)
    at emitErrorNT (node:internal/streams/destroy:157:8)
    at emitErrorCloseNT (node:internal/streams/destroy:122:3)
    at processTicksAndRejections (node:internal/process/task_queues:83:21) {
  errno: -32,
  code: 'EPIPE',
  syscall: 'write'
}

This happens as soon as I bring the application up in the browser. Looks like upgrading to Websocket is failing with this error.
Proxying to a Django server with Graphql support.

How often does it reproduce? Is there a required condition?

Everytime. If I set 'ws:false', the error does not happen

What is the expected behavior?

No EPIPE write error and node stays up and services the graphql calls by proxying them to the Django server.

What do you see instead?

EPIPE write error as shown in the output above.

Additional information

No response

[F3n67u]

Hi, @boomdizz. Could you help me understand how proxy.conf.js is used in your development server to achieve proxy? I don't know what development server you use. Seems some details is missing.

[boomdizz]

Since we are using Angular for the UI, we use ng in this manner:
ng serve --proxy-config proxy.conf.js --host 0.0.0.0
The proxy.conf.js file is the file I indicated in the initial bug filing.
So, when launched as a development server the UI makes graphql calls to the development server (node), which uses the proxy file to route the request/response back and forth with the Django backend.

[F3n67u]

Ng serve use webpack development server, webpack proxy make use of https://github.com/chimurai/http-proxy-middleware.
So I search for similar issue on http-proxy-middleware repo and found chimurai/http-proxy-middleware#675 and #41062. #41062 is similar but not the same problem.

I think it will better if we could make a reproduction with only node, no ng serve and http-proxy-middleware stuff.