ironworks

ironworks is a worker (plug-in) based framework to assist in creating a modular, interconnected microservice ecosystem

it provides several built-in workers as well as a base class to create custom workers

Documentation (coming soon)

Installation

npm install ironworks

Overview

services

• a Service is a container for workers
• a Worker is added to a Service using the use(worker) method
• when all workers are added, call the start() method
• when a Service is started, it calls workflow methods on each worker:
  • preInit(comm, whoService, [callback])
    • this is mainly an internal step - it should not be overridden under normal circumstances
    • comm is the instance of iron-beam that serves as ironworks shared eventing engine
    • whoService is an object with the name and id of the service
    • callback accepts an error parameter
    • always return super.preInit(comm, whoService, [callback]) from this method
  • init([callback])
    • this is the step where listeners are created
    • listeners can be created after this step, but certain Service features will not take them into account
    • callback accepts an error parameter
    • always return super.init([callback]) from this method
  • postInit([dependencies], [callback])
    • this step is used to interact with other workers once they have created their listeners in init
    • dependencies will be a Collection of workers that this worker depends on - those workers will have already completed their postInit step
    • callback accepts an error parameter
    • always return super.postInit([dependencies], [callback]) from this method
  • start([dependencies], [callback])
    • this step is used to interact with other workers once they have be started
    • dependencies will be a Collection of workers that this worker depends on - those workers will have already completed their start step
    • callback accepts an error parameter
    • always return super.start([dependencies], [callback]) from this method
  • postStart([dependencies], [callback])
    • this step is used to interact with other workers after they have been started
    • dependencies will be a Collection of workers that this worker depends on - those workers will have already completed their postStart step
    • callback accepts an error parameter
    • always return super.postStart([dependencies], [callback]) from this method
• call getWorker(name, callback) to get a worker from a started service - callback accepts an error and the worker, if found
• call dispose([callback]) to stop a service which will dispose it's workers and release it's listeners and other references - callback is optional and does not accept an error parameter (disposal errors are handled internally through stdout)

workers

• a Worker is a class that overrides service workflow methods in order to add event listeners to accomplish some task
  • eventing methods - ironworks uses 6 pairs of methods for emitters/listeners, instead of just emit/on, so that the parameter signature will be known to the framework
    • tell('event') -> listen('event')
      • the simplest form where no information is sent or received - the event occurence is all that is needed
    • inform('information', { some: 'info' }) -> info('information', (info) => {...})
      • the emitter is providing information to the listener
    • confirm('task', (e) => {...}) -> verify('task', (cb) => {...})
      • the emitter needs to know when a listener has performed it's task
    • check('receipt', { product: 'data' }, (e) => {...}) -> ack('receipt', (product, cb) => {...})
      • the emitter needs to know when a listener has performed it's task on the provided information
    • ask('question', (e, answer) => {...}) -> answer('question', (cb) => {...})
      • the emitter needs information from the listener
    • request('action', { request: 'data' }, (e, response) => {...} -> respond('action', (req, cb) => {...})
      • the emitter needs to get information from a listener about the provided information

event namespacing

ironworks uses a 5 part namespce for all event names - (i.e. - comm.service-name.request.my-worker.do-task)

• prefix
  • used to create distinct channels for events inside the same service
  • defaults to 'comm'
• service
  • used to identify the target service name when communicating between mulitple services
• method
  • the name of the "emit" method name used (i.e. - request, tell, check, etc.)
• worker
  • the worker name that houses the listener for the event
• name
  • the name of the event

built-in workers

• http server
  • can be used to serve static files
  • can provide a REST api for all listeners not annotated with { internal: true }
• socket
  • depends on HttpServerWorker
  • can be used to receive communication from other ironworks services via ConnectorWorker
  • can provide a socket.io api for all listeners not annotated with { internal: true }
• auth
  • depends on HttpServerWorker and SocketWorker
  • can authenticate event listener endpoints using jwt tokens
  • can authorize event listeners endpoints using roles
• log
  • will log all events to stdout
  • events can be annotated { log: { level: [detail number] } } to control the detail level of the logs
• metric
  • will emit comm.[service name].inform.iw-metric-[metric worker name].increment for every event so that counts can be calculated
  • will emit comm.[service name].inform.iw-metric-[metric worker name].duration for every event so that execution time averages can be calculated
• connector
  • used to connect to other ironworks services
  • more to come!
• environment
  • used to get environment variables from the system

examples

http file server

import ironworks = require('ironworks');
import Service = ironworks.service.Service;
import HttpServerWorker = ironworks.workers.HttpServerWorker;

new Service('my-file-server')
    .use(new HttpServerWorker({
        port: 9967,
        rootSitePagePath: "index.html", //the file served for the site root
        hapi: { // this entire object is passed to hapi, any valid hapi option can be used
            connections: {
                routes: {
                    files: {
                        relativeTo: path.resolve('./content/public')
                    }
                }
            }
        }
    })
    .start();

http REST api server

import ironworks = require('ironworks');
import Service = ironworks.service.Service;
import HttpServerWorker = ironworks.workers.HttpServerWorker;

new Service('my-api-service')
    .use(new HttpServerWorker({
        port: 9967,
        apiRoute: 'api' // used to separate the ironworks REST endpoints from your other urls
    })
    .answer('echo-endpoint', (req, cb) => {
        cb(null, req);
    }) // this will create an endpoint at http://hostname:9967/api/comm/my-api-service/ask/iw-service/echo-endpoint?some=data
    .start();

more examples on the way