a proxy pipe server

server.js

const URL = require('url')
const http = require('http')
const https = require('https')

const {
    PORT = 8080,
    HTTP_PROXY = 'https://username:password@localhost:443',
} = process.env

const proxy = URL.parse(HTTP_PROXY)
const proxyHeaders = { 'proxy-authorization': `Basic ${Buffer.from(proxy.auth).toString('base64')}` }
delete proxy.auth

const server = http.createServer().listen(PORT)

const destroy = (...sockets) => (
    sockets.forEach(socket => { try { socket.destroy() } catch (_) {} })
)

server.on('request', (req, res) => {
    const { method, url, headers, socket } = req

    if (!/^http:\/\//.test(url)) {
        res.writeHead(400)
        res.end()
        return
    }

    const proxyReq = (proxy.protocol === 'http:' ? http : https)
        .request({
            ...proxy,
            method,
            path: url,
            headers: {
                ...headers,
                ...proxyHeaders,
            },
            servername: proxy.hostname,
        })
        .on('error', () => {
            destroy(proxyReq.socket, socket)
        })
        .on('response', proxyRes => {
            res
                .on('error', () => {
                    destroy(proxyReq.socket, socket)
                })
                .writeHead(proxyRes.statusCode, proxyRes.headers)
            proxyRes
                .on('error', () => {
                    destroy(proxyReq.socket, socket)
                })
                .pipe(res)
        })

    req
        .on('error', () => {
            destroy(socket, proxyReq.socket)
        })
        .pipe(proxyReq)
})

server.on('connect', (req, socket, head) => {
    const { url, headers } = req

    const proxyReq = (proxy.protocol === 'http:' ? http : https)
        .request({
            ...proxy,
            method: 'CONNECT',
            path: url,
            headers: {
                ...headers,
                ...proxyHeaders,
            },
            servername: proxy.hostname,
        })
        .on('error', () => {
            destroy(socket, proxyReq.socket)
        })
        .on('connect', (_, proxySocket) => {
            socket.on('error', () => destroy(socket, proxySocket))
            proxySocket.on('error', () => destroy(socket, proxySocket))
            socket.write('HTTP/1.1 200 Connection established\r\n\r\n')
            proxySocket.write(head)
            proxySocket.pipe(socket)
            socket.pipe(proxySocket)
        })
        .end()
})