network-discovery

This is a lightweight service which can be used to find a service in a network.

CLI Usage

There is a server which provides a simple REST API. On that server the discovery service must be started:

discovery-service simple-api 1.0

Now on any other device in the same network, this service can be found with:

discover-service simple-api 1.0

Node Module Usage

This service can also be integrated in any node application. Just install it:

npm install --save network-discovery

And then start the discovery service with:

const {startDiscovery} = require('network-discovery');
startDiscovery({application: 'simple-api', version: '1.0'});

Now the server can be found by the CLI.

Protocol

The protocol is very simple. It just listen to an UDP port. The client sends a datagram to the network broadcaster. When the server receive a datagram with the same application name and the same version, the server will response to the address and port where the datagram came from.

Packet

The structure of the packet is as the following:

• 2 bytes magic number: 0xaf 0xbf
• 2 bytes length of application name (big endian)
• application name in ascii
• 2 bytes length of version (big endian)
• version in ascii

And the response:

• 2 bytes magic number: 0xaf 0xcf