Grégory Horion gregory

Stuff I wish I'd known sooner about service workers

I recently had several days of extremely frustrating experiences with service workers. Here are a few things I've since learned which would have made my life much easier but which isn't particularly obvious from most of the blog posts and videos I've seen.

I'll add to this list over time – suggested additions welcome in the comments or via twitter.com/rich_harris.

Use Canary for development instead of Chrome stable

~~Chrome 51 has some pretty wild behaviour related to console.log in service workers. Canary doesn't, and it has a load of really good service worker related stuff in devtools.~~

Common Options

-#, --progress-bar Make curl display a simple progress bar instead of the more informational standard meter.

-b, --cookie <name=data> Supply cookie with request. If no =, then specifies the cookie file to use (see -c).

-c, --cookie-jar <file name> File to save response cookies to.

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

Clarify and agree on the scope of the system

User cases (description of sequences of events that, taken together, lead to a system doing something useful)
- Who is going to use it?
- How are they going to use it?

In this gist I would like to describe an idea for GraphQL subscriptions. It was inspired by conversations about subscriptions in the GraphQL slack channel and different GH issues, like #89 and #411.

Conceptual Model

At the moment GraphQL allows 2 types of queries:

query
mutation

Reference implementation also adds the third type: subscription. It does not have any semantics yet, so here I would like to propose one possible semantics interpretation and the reasoning behind it.

Docker GNATSD Cluster example

Below is an example of how to setup gnatsd cluster using Docker.

I have put 3 different configurations (one per gnatsd server) under a folder named conf as follows:

tree conf

This gist is an implementation of http://sirile.github.io/2015/05/18/using-haproxy-and-consul-for-dynamic-service-discovery-on-docker.html on top of Docker Machine and Docker Swarm.

	sudo: required #is required to use docker service in travis

	language: php #can be any language, just php for example

	services:
	- docker # required, but travis uses older version of docker :(

	install:
	- echo "install nothing!" # put your normal pre-testing installs here

	let timeout = 1000;

	/**
	* Create a custom observable that creates a XHR request and returns complete when the promise is fulfilled
	*/
	let observable = Rx.Observable.create((o) => {
	dataService.fetch('test.json')
	.then((data) => {
	o.onNext(data);
	o.onCompleted();

	var fs = require('fs');
	var util = require('util');
	var request = require('request');

	var clientId = 'test-app'; // Can be anything
	var clientSecret = 'f6f0bfec08274b8790520a9079b808af'; // API key from Azure marketplace

	var str = 'This is a cool demo to call Microsoft text to speach service in Node.js.';

	console.log('Converting from text -> speech -> text.');

	#cloud-config
	hostname: rancher-os
	ssh_authorized_keys:
	- ssh-rsa REPLACE_WITH_PUBLIC_SSH_KEY
	rancher:
	debug: false
	cloud_init:
	datasources:
	- ec2
	state: