straightforward

🏴 straightforward

A straightforward forward-proxy written in Node.js

Goals

• Extremely focused (~200 SLOC), no-fuzz forward proxy
• Support HTTP, HTTPS, CONNECT & Websockets (wss)
• Performant: By default all requests/responses are streamed
• No external dependencies, small, self-contained, tested
• Support both cli and extensible programmatic usage
• Straightforward: no implicit magic or abstractions

What you can do with it

• Start an explicit forwarding proxy in seconds that just works
• Optionally use authentication
• Mock responses to test code using a proxy
• Allow others to surf with your IP address
• Use it programmatically to do whatever you want

What this is not

• A ssl-intercepting proxy (https can be filtered but not modified)
• A reverse proxy to load-balance stuff to internal servers
• A general purpose webserver framework
• A proxy middleware for express
• A transparent forward proxy
• A caching proxy
• A sni proxy

Installation

# Use directly with no installation (npx is part of npm):
❯❯❯ npx straightforward --port 9191

# Or install globally:
❯❯❯ npm install -g straightforward

Usage (cli)

❯❯❯ straightforward --help

Usage: straightforward --port 9191 [options]

Options:
      --version        Show version number                             [boolean]
  -p, --port           Port to bind on                  [number] [default: 9191]
  -a, --auth           Enable proxy authentication                      [string]
  -e, --echo           Enable echo mode (mock all http responses)      [boolean]
  -d, --debug          Enabled debug output                            [boolean]
  -c, --cluster        Run a cluster of proxies (using number of CPUs) [boolean]
      --cluster-count  Specify how many cluster workers to spawn        [number]
  -q, --quiet          Suppress request logs                           [boolean]
  -s, --silent         Don't print anything to stdout                  [boolean]
  -h, --help           Show help                                       [boolean]

Examples:
  straightforward --auth "user:pass"  Require authentication
  straightforward --echo              Mock responses for all http requests

Use with cURL:
  curl --proxy https://localhost:9191 'http://example.com' -v
  curl --proxy https://user:pass@localhost:9191 'http://example.com' -v

Usage (code)

// ESM/TS: import { Straightforward, middleware } from "straightforward"
const { Straightforward, middleware } = require("straightforward")

;(async () => {
  // Start proxy server
  const sf = new Straightforward()
  await sf.listen(9191)
  console.log(`Proxy listening on http://localhost:9191`)

  // Log http requests
  sf.onRequest.use(async ({ req, res }, next) => {
    console.log(`http request: ${req.url}`)
    // Note the common middleware pattern, use `next()`
    // to pass the request to the next handler.
    return next()
  })

  // Log connect (https) requests
  sf.onConnect.use(async ({ req }, next) => {
    console.log(`connect request: ${req.url}`)
    return next()
  })

  // Use built-in middleware for authentication
  sf.onRequest.use(middleware.auth({ user: "bob", pass: "alice" }))
  sf.onConnect.use(middleware.auth({ user: "bob", pass: "alice" }))

  // Use built-in middleware to mock responses for all http requests
  sf.onRequest.use(middleware.echo)
})()

In action

❯❯❯ straightforward --port 9191

Example: Secure proxy on fresh server in 30 seconds

Let's say you have a fresh linux server and want to use it as an authenticated forward proxy quickly.

• Make sure nvm is installed:
  • curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.33.11/install.sh | bash
• Make sure a recent version of Node.js is installed:
  • nvm install node && nvm use node && node --version
• Add forever (process manager) and straightforward:
  • npm install -g forever straightforward
• Start proxy daemon:
  • forever start --id "proxy1" $( which straightforward ) --port 9191 --quiet --auth 'user:foobar'
• Test your proxy from a different machine:
  • curl --proxy http://user:foobar@SERVER:9191/ http://canhazip.com
• List all running forever services:
  • forever list
• Stop our proxy service daemon:
  • forever stop proxy1

API

onRequest

Middlewares triggered when http requests occur

sf.onRequest.use(async ({ req, res }, next) => {
  console.log(`http request: ${req.url}`)
  // Note the common middleware pattern, use `next()`
  // to pass the request to the next handler.
  return next()
})

Middlwares can be chained:

sf.onRequest.use(
  async ({ req, res }, next) => {
    console.log(`middleware1`)
    return next()
  },
  async ({ req, res }, next) => {
    console.log(`middleware2`)
    res.writeHead(200, { "Content-Type": "text/html; charset=utf-8" })
    res.end("Hello world")
  }
)

onResponse

Middlewares triggered when http request responses are available

sf.onResponse.use(async ({ req, res, proxyRes }, next) => {
  console.log(`http response`)
  return next()
})

onConnect

Middlewares triggered when https and wss requests occur

sf.onConnect.use(async ({ req, clientSocket, head }, next) => {
  console.log(`connect request`)
  return next()
})

License

MIT