ms-manager

How to use ms-manager

ms-manager is based on Hydra project, leaded by Cjus. This version add easy messaging and answer.

Configuration

In order to work properly, you need redis server to run (A docker container works too ! ;)) A configuration file is needed, generally .config/config.json and should contain the following:

{  
	"environment": "<environment of this service (ex: development)>",  
	"hydra": {  
		"serviceName": "<name of this service [required]>",  
		"serviceIP": "<ip of the service>",  
		"servicePort": 9000,  
		"serviceType": "<type of this service>",  
		"serviceDescription": "<description of this service>",  
		"redis": {  
		    "url": "redis://127.0.0.1:6379/0"  
		}  
	}  
}

Don't forget to provide the url of redis. If you use docker, you should use process.env.REDIS_PORT + '/0'

API

initialization

The following code let's you register your micro-service:

	const MM = require('ms-manager');  
	let config = require(`./config/config.json`) || {};  
  
	config['hydra']['redis']['url'] = process.env.REDIS_PORT + '/0';  
  
	MM.init(config, (err, serviceInfo) => {  
	    if (err) {  
	        console.error(err);  
		} else {  
	        /**  
			 * Our micro-service is now up. 
			 * */
			 console.log('#Micro-service UP#');  
		}  
	});

Send message

You can send a message to a specific service with a specific purpose with the following code:

const MM = require('ms-manager');  
MM.send('targeted-service')
	.for('my-message')
	.with(obj);

In this code:

• .send('targeted-service') specifies which micro-service is required.
• .for('my-message') specifies which message is send.
• .with(obj) add an object to the message.

The message can be string as well as a json object.

In order to retrieve the answer, you can add the .done(callback) to the chain, like the following:

const MM = require('ms-manager');  
MM.send('targeted-service')
	.for('my-message')
	.with(msg)
	.done((err, obj) => {
		if (err) {
			console.error(err);
		} else {
			console.log(obj);
		}
	});

Subscribe and reply to a message

You can subscribe to specific messages with the following code:

const MM = require('ms-manager');  
MM.subscribe('my-message', (bdy, msg) => {  
	/**
	 * bdy contains the string / json message sent
	 **/
	 process(bdy);
	 
	/**
	 * You can send back an error with msg.replyErr();
	 **/
	 msg.replyErr(err);
	 
	/**
	 * You can send back a string or an object with msg.reply();
	 **/
	 msg.reply(obj);  
});

Example

You can see a demo project at https://github.com/adrienfenech/mymicroservice