Kimbu NPM | npm.io

kimbu

Author: Kurt Pattyn.

Kimbu is a message bus framework that implements publish-subscribe and request-response messaging patterns. It abstracts away from the underlying message transport by using pluggable messaging transport providers. Currently, only a RabbitMQ messaging transport provider has been implemented.

Motivation

Implementing publish-subscribe and request-response messaging patterns using existing transports (e.g. AMQP, WebSockets), requires some extensive boilerplate code. Using RabbitMQ for instance, to implement a publish-subscribe messaging pattern one needs to setup a fanout exchange and bind the consumers via queues to that exchange. For the request-response style of messaging, a reply queue needs to be set up and messages must be tagged with a correlation-id and replyTo field. When messages return they must be matched to the request using the correlation-id. Although not difficult, this requires a lot of boilerplate code.

Installation

$ npm install kimbu

$ npm install kimbu --production

for a production only installation (no tests, documentation, ...).

Supported Node Versions

Kimbu supports Node versions 0.12 and later.
To use Kimbu with Node versions < 4.0, you must start node with the --harmony flag.

Usage

  var Client = require("kimbu").Client;
  var Transport = require("kimbu").Transport;
  var RabbitMQTransport = Transport.providers.RabbitMQTransport;

  var rmq = new RabbitMQTransport();  //use default options
  var client = new Client("client1", rmq, function(err) {
    client.on("calculator.add", function(parameters, next) {
      var result = parameters.reduce(function(prevVal, curVal) {
        return prevVal + curVal;
      });
      next(result);
    });
    client.on("buttonPushed", function(parameters, next) {
      console.log("Button %s pushed.", parameters);
      next();
    });
    client.start(function(err) {
      client.request("calculator.add", [1, 2, 3, 4, 5], function(err, reply) {
        console.log("The sum of 1, 2, 3, 4 and 5 is", reply);
      });
      client.publish("buttonPushed", "Enter");
    });
  });

Tests

Unit Tests

$ npm test

Unit Tests with Code Coverage

$ npm run test-cov

This will generate a folder coverage containing coverage information and a folder coverage/lcov-report containing an HTML report with the coverage results.

$ npm run test-ci

will create a folder coverage containing lcov formatted coverage information to be consumed by a 3rd party coverage analysis tool. This script is typically used on a continuous integration server.