dynamic-reverse-proxy

dynamic-reverse-proxy

A reverse proxy built on http-proxy that is configured by REST.

Starting the server

var http = require("http"),
    server = http.createServer(),
    dynamicProxy = require("dynamic-reverse-proxy")();

server.on("request", function (req, res) {
  if (req.url.match(/^\/register/i)) {
    proxy.registerRouteRequest(req, res);
  }
  else {
    proxy.proxyRequest(req, res);
  }
});

server.listen(3000, function () {
  console.log("Reverse Proxy started, listening on port 3000");
});

Configuring the proxy

The reverse proxy is configured to route based on the first segment of the path. For example:

• / would route to the host registered at /
• /application1 would route to the host registered at /application1
• /application2/test/index.html would route to the host registered at /application2

To register the a host with the proxy:

POST /register HTTP/1.1
Host: localhost:3000
Content-Length: 28
Content-Type: application/json

{"prefix": "/", "port":1234}

Now, any request made to http://localhost:3000/ will be sent to http://localhost:1234/.

To register another host:

POST /register HTTP/1.1
Host: localhost:3000
Content-Length: 32
Content-Type: application/json

{"prefix": "/test", "port":4321}

Now, any request made to http://localhost:3000/test will be sent to http://localhost:4321/test.

Wait, what about security?

Well, it's pretty lame (but functional) at the moment. Only requests originating from the same machine as the proxy are allowed to register.

Events

The dynamic proxy object that is returned is an EventEmitter with the following events:

• proxyError is passed (error, host, request, response) and is emitted when:

  • A request is sent to a known host but the request could not be proxied (likely the host was unreachable). If no handler ends the response back to the original client, 500 Internal Server Error will be returned.
  • No host could be found to handle the request. In this case, the error will be NOT_FOUND. If no handler ends the response back to the original client, 501 Not Implemented will be returned.

• registerError is passed (error, request, response) and is emitted when a request is sent to /register but it could not be handled correctly. Error will be one of the following:

  • FORBIDDEN (not allowed)
  • METHOD_NOT_ALLOWED (must be a POST)
  • BAD_REQUEST (not parsable as JSON)
  • INCOMPLETE_REQUEST (path and port were not supplied)

• routeRegistered is passed (host) and is emitted when a request is sent to /register and it was successful.

Methods

• dynamicProxy.addRoutes(routes) adds an object of routes in the following format:

{
   "/": {
      "prefix": "",
      "port": 1234
   },
   "/test": {
      "prefix": "test",
      "port": 4321
   }
}