#AMQP Pipes and Filters

This is a small implementation of pipes and filters with the amqp.node (amqplib) library for RabbitMQ.

##install run

$ npm install amqp-pipes

##How to In order to use this library, you need to provide:

• A config file (.json) with all the connection and pipe/filter details
• Your own filter implementations
• A publisher with the first input
• A consumer taking the result

obviously a server instance of RabbitMQ should be running.

##Example your config file should look like this: (these connection details are the unmodified RabbitMQ standard, so this should work for you if you just installed it)

{
  "connection": {
    "host": "localhost",
    "port": "5672",
    "user": "guest",
    "pwd": "guest"
  },
  "filterPath": "../../filters/",
  "pipes": [
    {
      "from": "lovely",
      "to": "greatness",
      "filter": "lovelyFilter.js"
    },
    {
      "from": "greatness",
      "to": "reinforce",
      "filter": "greatnessFilter.js"
    },
    {
      "from": "reinforce",
      "to": "result",
      "filter": "reinforceFilter.js"
    }
  ]
}

"from": specifies the exchange from which the messages get consumed "to": specifies the exchange to which the messages get published "filter": your filter implementation, which is applied on the content of the messages

All your filters require a "process(body)" function, in order to get accessed by the pipes.

module.exports = function GreatnessFilter() {

  this.process = function(body) {
    var input = body.toString();

    var result = input.toUpperCase();

    return result;
  }
}

require 'amqp-pipes' & your config file and simply run the module with your config file. This sets up all pipes and filters specified in your config.

var pipes = require('amqp-pipes');
var filters = require('./config.json');

pipes(filters);

You can find a full runnable example in the example directory here: https://github.com/mfressdorf/AMQP-pipes-and-filters/example