no.php

Transparent reverse proxy written in PHP that allows you to not have to write PHP any more.

This short, single-file, 130-line PHP script is a simple and fully transparent HTTP(S) reverse proxy written in PHP that allows you to never have to use PHP again for a new project, if you feel so inclined, for example if you are forced to host on a fully 3rd-party-managed server where you can't do more than run PHP and upload files via FTP. The PHP script simply reads all requests from a browser pointed to it, forwards them (via PHP's curl library) to a web application listening at another URL (e.g. on a more powerful, more secure, more private, or more capable server in a different data center), and returns the responses transparently and unmodified.

Supports:

• Regular and XMLHttpRequests (AJAX)
• All HTTP headers without discrimination
• GET and POST verbs
• Content types (HTTP payload) without discrimination
• Redirects (internal redirects are rewritten to relative URIs)
• Multipart content type

Does not support (or not tested):

• HTTP verbs other than GET and POST (but these are usually emulated anyway)
• HTTP greater than version 1.1 (e.g. reusable connections)
• Upgrade to websocket (persistent connections)

Usage illustrated by the standard example

You have a non-PHP web application (called the "backend") listening on https://myapp.backend.com:3000 but due to constraints you must make it available on a shared hosting server called https://example.com/subdir which only supports PHP and can't be configured at all. On latter server, Apache (or Nginx, doesn't matter) will usually do the following:

1. If a URI points to a .php file, this file will be interpreted
2. If a URI points to a file that is not existing, a 404 status will be returned.

Using no.php, to accomodate the second case, all URIs of the proxied web app (including static files) must be appended to the URI https://example.com/subdir/no.php. For example:

https://example.com/subdir/no.php/images/image.png
https://example.com/subdir/no.php/people/15/edit

If your backend app supports that extra /subdir/no.php prefix to all paths, you are all set and ready to use no.php. Then:

1. Simply copy no.php into the subdir directory of example.com
2. Change $backend_url in no.php to "https://myapp.backend.com:3000"
3. Point a browser to https://example.com/subdir/no.php

In Ruby on Rails for example you must do a minimal adaptation to facilitate the mentioned URL prefix -- please consult the Ruby on Rails documentation for full details, but here is a hint:

ENV['RAILS_RELATIVE_URL_ROOT'] = "/subdir/no.php"

Rails.application.configure do
  config.relative_url_root = ENV['RAILS_RELATIVE_URL_ROOT']
end

Rails.application.routes.draw do
  scope path: ENV['RAILS_RELATIVE_URL_ROOT'] do
    # routes here
  end
end

Project status

Experimental. Use only if you know what you are doing.

Support

This most likely is the only PHP code I will ever write voluntarily and without pay, so I do not provide support for this project. But feel free to make improvements and create pull requests.

License

Copyright (c) 2016, 2017 Michael Franzl

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.