kuiper

Intended to be a service discovery module by Antares Tech, for micro-services based architecture using simple NATS messaging.

Base Idea

Two components:

App      : Entity that wants to look for services.
Service  : Entity that will announce it's presence and a way to reach them. Presence announcement will be made periodically and on demand.

Both Apps and Services will connect to a NATS server and listen on configured channels for messages. Services will broadcast their presence every "pre-configured" duration. In this broadcast, Services will also send out useful information such as "networkInfo" and other custom data if needed.

Apps will be listening to broadcast messages from services and managing, cataloging(among other things) all services. Managing will include keeping count of how many services of which type (user, media etc) are up etc. App module will provide all live services information when requested.

Usage

NOTE : User will need to have a nats server running to be used as message broker. This module uses nats for service discovery protocol message transfers.

Basic usage

App component

IMPORTANT : natsConfig(in appClient.init() function call) should be in accordance with nats module

const appClient = require ('kuiper').appClient;

async function init () {
	/*
	 * Configuration options for appClient */
	let config = {
		"name" : "myApp" 
	};

	try {
		await appClient.init (config /*, natsConfig */); // native JS promise
		/*
		 * Once initialised
		 * get list of services anytime by calling getServices API */
		let currentServices = appClient.getServices ();
		console.log ({currentServices}, 'list of services available at this moment');
	}
	catch (err) {
		/*
		 * handle init error */
		console.log ({err}, 'an error occured in kuiper initialisation');
	}
}

init ();

Service component

IMPORTANT : natsConfig(in serviceClient.init() function call) should be in accordance with nats module

const serviceClient = require ('kuiper').serviceClient;

async function init () {
	let config = {
		"id"   : "uniqueServiceID-001", //this should be unique for a service name
		"name" : "serviceType", //this is used to categories different instance of a service type on app side
	};

	try {
		await serviceClient.init (config/*, natsConfig */);
	}
	catch (err) {
		/*
		 * handle service init error */
		console.error ({err}, 'error in serviceClient init');
	}
}

init ();

Setup dev environment

Setup your Ubuntu 18.04 Development Environment by runnning the following command

cd scripts
./setup.sh

TODO in usages

• List all APIs (and their examples) for appClient and serviceClient
• What kind of data will app get on appClient.getServices ()
• List all config options for appClient.init ()
• List all config options for serviceClient.init ()
• Examples of other config option usages