iopa-coap-packet

About

iopa-coap-packet is a lightweight Constrained Application Protocol (CoAP) packet transport, based on the Internet of Protocols Alliance (IOPA) specification

It translates CoAP packets to and from standard IOPA format.

It is not intended as a standalone CoAP server, as it does not contain the standard protocol logic for acknowledges, observes etc., but can form the basis for one. See iopa-coap for an open-source, standards-based, drop-in replacement for CoAP servers such as node-coap.

iopa-coap-packet uses the widely used library 'coap-packet' for protocol formatting.

Written in plain javascript for maximum portability to constrained devices

Makes CoAP messages look to an application just like an HTTP message so little or no application changes required to support multiple REST protocols

Status

Fully working prototype include server and client.

Includes:

Server Functions

• Layered protocol based on native UDP sockets
• Translation from UDP Raw Message to CoAP Packet in standard IOPA format, compatible with all HTTP and COAP applications including those written for Express, Connect, etc!

Client Functions

• Layered protocol based on native UDP sockets
• Translation from CoAP Packet in standard IOPA format to CoAP Raw Message

Installation

npm install iopa-coap-packet

Usage

Simple Hello World Server and Client

const iopa = require('iopa')
    , coap = require('iopa-coap-packet')      
 
var appServer = new iopa.App();
 
appServer.use(function(context, next){
   context.log.info("[DEMO] SERVER CoAP DEMO " + context["iopa.Method"] + " " + context["iopa.Path"]);
   
   if (context["iopa.Method"] === "GET")
   {
      context.response["iopa.Body"].end("Hello World");
   }
 
   return next();
    });
    
    
var appClient = new iopa.App();
 
appClient.use(function(context, next){
   context.log.info("[DEMO] CLIENT CoAP DEMO " + context["iopa.Method"] + " " + context["iopa.Path"]);
   return next();
    });
                       
var server = coap.createServer({}, appServer.build(), appClient.build());
 
server.listen(process.env.PORT, process.env.IP)
  .then(function(){
    server.log.info("[DEMO] Server is on port " + server.port );
    return server.connect("coap://127.0.0.1");
  })
  .then(function(coapClient){
    var context = coapClient.send("/device", "GET");
    })
   .then(function(response){
       server.log.info("[DEMO] CoAP DEMO Response " + response["iopa.Method"] + " " + response["iopa.Body"].toString());
    })
 ;

Roadmap

Adding additional features of the protocol such as Type 2 Blocks, is as simple as adding a new middleware function (10-30 lines of javascript)