npr

A nodejs proxy server.

Supports TCP in proxy mode, HTTP and Websocket in router mode.

Installation

• Standalone Installation (as command line utility):
  sudo npm install npr -g

• Modular Installation (as a node module):
  sudo npm install npr

Startup (as command line utility)

• Start the proxy server with default configuration npr.json:
  npr

• Start the proxy server with selected configuration google.json:
  npr google.json

• Start the proxy server with multiple configurations google.json ms.json:
  npr google.json ms.json

Use as node module

var npr = require('npr');
 
var configProxy1 = {
    "dstPort": 80,
    "localPort": 3000,
    "dstAddr": "www.microsoft.com"
};
 
var configProxy2 = {
    "dstPort": 80,
    "localPort": 2000,
    "dstAddr": "www.google.com"
};
 
var configRouter = {
    "localPort": 8000,
    "routes": {
        "hosta": {
            "dstAddr": "127.0.0.1",
            "dstPort": 10309
        },
        "default": {
            "dstAddr": "127.0.0.1",
            "dstPort": 10309
        }
    }
};
 
npr.run(configProxy1);
npr.run(configProxy2);
npr.run(configRouter);

Proxy mode

A configuration npr.json looks like this:

{
  "microsoft" : {
    "dstPort" : 80,
    "localPort" : 3000,
    "dstAddr" : "www.microsoft.com"
  },
  "google" : {
    "dstPort" : 80,
    "localPort" : 2000,
    "localAddr" : "127.0.0.1",
    "dstAddr" : "www.google.com"
  }
}

means that:
when the clients connect to 127.0.0.1:3000, they connect to www.microsoft.com:80, and when the clients connect to 127.0.0.1:2000, they connect to www.google.com:80.

Please note that localAddr is not necessary, when omitted, the server will listen on all network interfaces.

Router mode

Router mode works only with HTTP, not even HTTPS. Proxy mode and router mode can be working together happily. A configuration npr.json looks like this:

{
  "google_ms" : {
    "localPort" : 4000,
    "routes" : {
      "hostname_a" : {
        "dstAddr" : "www.microsoft.com",
        "dstPort" : 80
      },
      "hostname_b" : {
        "dstAddr" : "www.google.com",
        "dstPort" : 80
      },
      "default" : {
        "dstAddr" : "www.yahoo.com",
        "dstPort" : 80
      }
    }
  }
}

means that:
if multiple host names / domain names are bound to the proxy server, let's say hostname_a and hostname_b. When the clients connect to hostname_a:4000, they connect to www.microsoft.com:80, and when the clients connect to hostname_b:4000, they connect to www.google.com:80. If the clients connect to a host name which is not in the route table, 127.0.0.1:4000 from the proxy server itelf, for example, they connect to the default route www.yahoo.com:80.