Originally posted on November 13th, 2017 (more info)
In a follow up to my last post, the following code takes an Express request, performs an external request, stores that response in a buffer which it then stores in Redis, which it then reads back, converts back into a buffer and sends that back to the Express response.
This doesn't store the headers or status code in Redis but it could easily be done.
This allows playback of a request/response cycle. Interesting concept really.
'use strict' const express = require('express') const request = require('request') const streamBuffers = require('stream-buffers') const through2 = require('through2') const redis = require('redis') const client = redis.createClient() client.on('connect', () => { console.log('redis connected' )}) client.on('ready', () => { console.log('redis ready' )}) client.on('reconnecting', () => { console.log('redis reconnecting' )}) client.on('error', () => { console.log('redis error' )}) client.on('end', () => { console.log('redis end' )}) const app = express() app.use('/', (incomingRequest, outgoingResponse) => { const outgoingRequest = request('http://via.placeholder.com/800x600?text=example') const randomKey = Math.random().toString(36).substr(2) const stream = new streamBuffers.WritableStreamBuffer() let _statusCode = null let _headers = null outgoingRequest.pipe(through2(function (chunk, enc, callback) { stream.write(chunk) callback() })) outgoingRequest.on('end', () => { const contents = stream.getContents() const base64 = contents.toString('base64') client.set(randomKey, base64) client.get(randomKey, (err, reply) => { const newBuffer = new Buffer(reply, 'base64') outgoingResponse.set(_headers).status(_statusCode) outgoingResponse.end(newBuffer) client.del(randomKey) }) }) outgoingRequest.on('response', (incomingResponse) => { _statusCode = incomingResponse.statusCode _headers = incomingResponse.headers }) }) app.listen(8000, () => { console.log('listening on 8000') }) 
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