The Transports systems is how skyring executes timeouts. When a timer lapses, a message is delivered to destination that you have defined. How that message is delivered is configurable. Out of the box, Skyring comes with an HTTP transport. Defining your own transport is pretty simple, and you can use any of the tools you are currently used to using.

STDOUT Transport

To illustrate the process, we're going to make a simple transport handler to write the data to stdout. Basically, speaking a transport is just a node.js module that exports a class. The class must, at the very least, have an exec function.

'use strict'

const os = require('os')

module.exports = class Stdout {

  constructor(opts) {
    // do set up
  }

  exec (method, url, payload, id, storage) {
    // deliver the message
    process.stdout.write(payload);
    process.stdout(os.EOL);

    // clear the timer
    storage.uccessid);
  }

  get [Symbol.toStringTag]() {
    return 'SkyringSTDOutTransport'
  }
};

Pretty simple. We just write the data to the stdout out stream attached to the process, of course, be sure to remove the timer reference from the skyring internal storage. To load your transport into a skyring server, you can pass an array of transports when instantiating as server instance. The array can contain references to the transport itself, or as string that can be passed to require

'use strict'

const Skyring = require('skyring')
const Stdout = require('./transports/stdout')
const server = new Skyring({
  transports: [Stdout]
, seeds: ['localhost:3455']
})

server.listen(3000)

Done. Just be sure that every skyring node in the cluster has all of the same transports loaded so they have the capability to execute all of the timers. Other than that, we can start using our new transport by referencing it by name in the transport field of the request to create a new timer.

curl -XPOST http://localhost:3000/timer -H 'Content-Type: application/json' -d '{
  "timeout":3000
, "data":"hello world!"
, "callback": {
    "transport": "stdout"
  , "method":"unused"
  , "uri": "unused"
  }
}'

It is pretty simple and straight forward to build your own transport layer for Skyring. It can be a simple function, or for more complex use cases, you can build out entire npm packages using whatever tools you want. This makes the transport system in skyring very flexible, powerful, and easy to use.