Abd ar-Rahman Hamidi hbakhtiyor

From zero to microservice with 𝚫 now

The following guide will show you how to deploy a simple microservice written in JavaScript using 𝚫 now.

It uses Open Source tools that are widely available, tested and understood:

Node.JS
NPM
Express

Crystal vs Node.js Websocket Benchmark

Crystal 0.9.1 with Kemal

require "kemal"

ws "/" do |socket|
  socket.on_message do |message|
 end

Don't use VPN services.

No, seriously, don't. You're probably reading this because you've asked what VPN service to use, and this is the answer.

Note: The content in this post does not apply to using VPN for their intended purpose; that is, as a virtual private (internal) network. It only applies to using it as a glorified proxy, which is what every third-party "VPN provider" does.

A Russian translation of this article can be found here, contributed by Timur Demin.
A Turkish translation can be found here, contributed by agyild.
There's also this article about VPN services, which is honestly better written (and has more cat pictures!) than my article.

Meteor Alternatives Per Feature

This table was created in 2015 so may be quite outdated today.

Feature	Meteor Solution	Alternative Solutions	Description
Live DB Sync	[livequery][lq] ([mongo-oplog]), [ddp]	RethinkDB, Redis, ShareDB, [npm:mongo-oplog], [firebase], etc.	Push DB updates to client/server.
Latency Compensation, Optimistic UI	[minimongo][mm]	[RethinkDB][lcr], [mWater/minimongo] (fork, not ws but http, browserify)	Imitate successful db query on client before it is done.
Isomorphic Code	[isobuild] & isopacks	browserify	Write one code for server/client/mobile.
Isomorphic Packaging	[isobuild], atmosphere		No more separate packages for server & client. Get bower + npm + mobile.

Question 1

What object-oriented programming advice is this code violating?

def check_for_overheating(system_monitor)
  if system_monitor.temperature > 100
    system_monitor.sound_alarms
  end
end

Encoding Video

Installing

Install FFmpeg with homebrew. You'll need to install it with a couple flags for webm and the AAC audio codec.

brew install ffmpeg --with-libvpx --with-libvorbis --with-fdk-aac --with-opus

Most VPN Services are Terrible

Short version: I strongly do not recommend using any of these providers. You are, of course, free to use whatever you like. My TL;DR advice: Roll your own and use Algo or Streisand. For messaging & voice, use Signal. For increased anonymity, use Tor for desktop (though recognize that doing so may actually put you at greater risk), and Onion Browser for mobile.

This mini-rant came on the heels of an interesting twitter discussion: https://twitter.com/kennwhite/status/591074055018582016

The Ultimate Unit Testing Cheat-sheet

Sinon Chai
Chai
Sinon

	The MIT License (MIT)

	Copyright (c) 2015 Justin Perry

	Permission is hereby granted, free of charge, to any person obtaining a copy of
	this software and associated documentation files (the "Software"), to deal in
	the Software without restriction, including without limitation the rights to
	use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
	the Software, and to permit persons to whom the Software is furnished to do so,
	subject to the following conditions:

	//equivalent of MySQL SELECT COUNT(*) AS cnt, fieldName FROM someTable GROUP BY fieldName;
	db.someCollection.aggregate([{"$group" : {_id:"$fieldName", cnt:{$sum:1}}}]);

	//as above but ordered by the count descending
	//eg: SELECT COUNT(*) AS cnt, fieldName FROM someTable GROUP BY fieldName ORDER BY cnt DESC;
	db.someCollection.aggregate([{"$group" : {_id:"$fieldName", cnt:{$sum:1}}}, {$sort:{'cnt':-1}}]);