network-service-discover

node-network-service-discover

A Node.js package to advertise and discover services running on your local network.

Motivation

This project started because i had several microservices as Node.js applications and wanted them to find each other without configuring the actual service entry point for their api on each application.

Using IPv4 udp broadcasts this package can adverstise and discover your services.

Installation

This package can be installed from the npm repository.

npm install network-service-discover

Code Example

For a minimal code example see minimal.js.

Run this example on multiple computers on your local network.

var NetworkServiceDiscover = require('network-service-discover');
var nsd = NetworkServiceDiscover();
 
nsd.start(
  {
    // Udp port to send and receive packets
    port: 7691,
 
    // Send broadcast packet every 15 seconds.
    advertise: 15,
 
    // Remove services from the list when they have not been received for 60 seconds.
    purge: 60,
 
    // Array of services we want to advertise on the network.
    //
    //  name   {string}   - Name of the service
    //  port   {integer}  - Udp port the service is listening on
    //  secure {bool}     - True if secured aka. SSL connection
    //  path   {string}   - Path for the RESTfull api
    service: [
      { name: 'WarehouseCatalog', port: 45241, secure: false, path: '/api/whc/V01/' },
    ],
 
    // Callback function called in case of an error.
    error: function(err) {
      err && console.log(err);
    },
 
    // Callback function called when new services are discovered.
    change: function(data) {
      console.log(data);      
    }
  },
  function(socket, err) {
    err && console.log(err);
  }
);
 
// Every minute output the list of discovered services to the console.
setInterval(
  function() {
    console.log('Discovered:', nsd.getServices());
  }, 
  60000
);
 

Debugging

To enable debug output you need to set the DEBUG environment variable to NetworkServiceDiscover.

SET DEBUG=NetworkServiceDiscover
npm start

License

node-network-service-discover is published under MIT license