fast-proxy

Node.js framework agnostic library that enables you to forward an http request to another HTTP server. Supported protocols: HTTP, HTTPS, HTTP2

This library was initially forked from fastify-reply-from: https://github.com/fastify/fastify-reply-from

fast-proxy powers: https://www.npmjs.com/package/fast-gateway 🚀

Install

npm i fast-proxy

Usage

The following examples describe how to use fast-proxy with restana:

Gateway:

const { proxy, close } = require('fast-proxy')({
  base: 'http://127.0.0.1:3000'
  // options
})
const gateway = require('restana')()

gateway.all('/service/*', function (req, res) {
  proxy(req, res, req.url, {})
})

gateway.start(8080)

Remote service:

const service = require('restana')()
service.get('/service/hi', (req, res) => res.send('Hello World!'))

service.start(3000)

Using imports:

import fastProxy from 'fast-proxy'

const { proxy, close } = fastProxy({
  base: 'http://127.0.0.1:3000'
})

Benchmarks

Please see: https://github.com/jkyberneees/nodejs-proxy-benchmarks

API

Options

base

Set the base URL for all the forwarded requests. Will be required if http2 is set to true Note that path will be discarded.

queryString

Set the query string parser and stringifier. By default fast-proxy uses the fast-querystring module. Configuration can be changed like so:

{
  base: 'http://localhost:3001/',
  queryString: {
    parse: (value) => qs.parse(value),
    stringify: (value) => qs.stringify(value),
  }
}

http2

Set to true if target server is http2 enabled.

undici

Set to true to use undici instead of require('http'). Enabling this flag should guarantee 20-50% more throughput.

This flag could controls the settings of the undici client, like so:

...
  base: 'http://localhost:3001/',
  undici: {
    connections: 100,
    pipelining: 10
  }
...

See undici demo at: demos/gateway-undici.js

cacheURLs

The number of parsed URLs that will be cached. Default: 100.

Use value = 0 to disable the caching mechanism

requests.http and requests.https

Allows to optionally overwrite the internal http and https client agents implementation. Defaults: http and https.

For example, this could be used to add support for following redirects, like so:

...
  requests: {
    http: require('follow-redirects/http'),
    https: require('follow-redirects/https')
  }
...

If using undici or http2 this settings are ignored!

keepAliveMsecs

Defaults to 1 minute, passed down to [http.Agent][http-agent] and [https.Agent][https-agent] instances.

maxSockets

Defaults to 2048 sockets, passed down to [http.Agent][http-agent] and [https.Agent][https-agent] instances.

rejectUnauthorized

Defaults to true, passed down to [https.Agent][https-agent] instances. This needs to be set to false to reply from https servers with self-signed certificates.

Extended configurations

Other supported configurations in https://nodejs.org/api/http.html#http_new_agent_options can also be part of the opts object.

close

Optional "on close resource release" strategy. You can link this to your application shutdown hook as an example.

proxy(originReq, originRes, source, [opts])

Enables you to forward an http request to another HTTP server.

proxy(
  originReq,                          // http.IncomingMessage 
  originRes,                          // http.ServerResponse
  req.url,                            // String -> remote URL + path or path if base was set
  {}                                  // Options described below
)

opts

base

Optionally indicates the base URL for the current request proxy. When used, the global base config is overwriten.

This configuration value is ignored when using HTTP2.

onResponse(req, res, stream)

Called when an http response is received from the source. The default behavior is pump(stream, res), which will be disabled if the option is specified.

rewriteRequestHeaders(req, headers)

Called to rewrite the headers of the request, before them being sent to the downstream server. It must return the new headers object.

rewriteHeaders(headers)

Called to rewrite the headers of the response, before them being copied over to the outer response. It must return the new headers object.

request

Extended options supported by http[s].request method (https://nodejs.org/api/http.html#http_http_request_options_callback) The following options are dynamically assigned: method, port, path, hostname, headers, agent.

http2 options are limited to timeout only, while undici supports none.

queryString

Replaces the original querystring of the request with what is specified. This will get passed to querystring.stringify.

Related topics

• http-agent: https://nodejs.org/api/http.html#http_new_agent_options
• https-agent: https://nodejs.org/api/https.html#https_class_https_agent

Contributions

Special thanks to fastify-reply-from developers for creating a production ready library from where we could initially fork.

License

MIT