Reverse proxy for nodejs debugger, for uWebSockets

heroku.js

import {default as uWS} from 'uWebSockets.js'
import WebSocket from 'ws';
import inspector from 'inspector';

const listeningPort = 3000
const secretToken = '83bc34ab-ef29-443e-92c8-56295d928449'

// connection link
// devtools://devtools/bundled/js_app.html?experiments=true&v8only=true&ws=yourhost.com/yourSecretToken

function injectDebugger() {
    if(!process.debugPort) return
    console.warn('Debugger is exposed')
    /**
     * @typedef {uWS.WebSocket & {connection: WebSocket}} uws_debugger_context
     */
    const nope = () => false
    const decoder = new TextDecoder()
    listenerSocket.ws('/' + secretToken,{
        idleTimeout: 36000,
        maxBackpressure: 51200,
        maxPayloadLength: 51200,
        compression: uWS.DEDICATED_COMPRESSOR_4KB,
        upgrade: async (res, req, context) => {
            const connection = new WebSocket(inspector.url())

            const upgradeData = [
                {connection},
                req.getHeader('sec-websocket-key'),
                req.getHeader('sec-websocket-protocol'),
                req.getHeader('sec-websocket-extensions'),
                context
            ]

            connection.onopen = () => {
                res.upgrade.apply(res, upgradeData);
            }
            connection.onerror = (error) => {}

            res.onAborted(() => {
                connection.close()
            });
        },
        /**
         * @param {uws_debugger_context} uws
         */
        open: (uws) => {
            uws.connection.onmessage = (event) => {
                // @ts-ignore
                uws.send(event.data, false, true)
            }
            uws.connection.onclose = () => {
                if(uws.send !== nope) uws.close()
            }
        },
        /** 
         * @param {uws_debugger_context} uws 
         * @param {ArrayBuffer} message
         * */
        message: (uws, message, isBinary) => {
            uws.connection.send(decoder.decode(message))
        },
        /** @param {uws_debugger_context} uws */
        close: (uws, code, message) => {
            uws.connection.close(1001)
            uws.send = nope
        }
    })
}

const listenerSocket = uWS./*SSL*/App({})
injectDebugger()
listenerSocket.listen("0.0.0.0", listeningPort, (listenSocket) => {
    console.log(`WS port opened: ${listeningPort}`)
    resolve()
})

How to connect to a debugger for a containerized nodejs application that uses uWebSockets.js ?
How to inspect applications in a Docker container?
How to inspect nodejs heroku or coolify.io apps?

This little snippet will answer your request.
This snippet is not recommended for use in production, the author of the script is not responsible for possible risks.
See your hosting provider for debugging instructions.