Nick Poorman nickpoorman

RethinkDB Setup on OSX

This guide will get RethinkDB setup and running with a default configuration on OSX. There is also an option for setting RethinkDB to start at boot time on OSX, and a note on upgrading to a more recent RethinkDB version.

First Installation

Install Homebrew if you don't already have it:

Apache Mesos Build scripts

The `Getting started`_ instructions are a good start (no surprise there!) but are somewhat incomplete and currently look a bit outdated (I plan to fix them soon): however, the outcome has been that I have struggled more than I felt necessary in building and running Mesos on a dev VM (Ubuntu 14.04 running under VirtualBox).

Some of the issue seem to arise from the unfortunate combination of Mesos Master trying to guess its own IP address, the VM being (obviously) non-DNS resolvable and, eventually, the Slave and the Framework failing to properly communicate with the Master.

In the process of solving this, I ended up automating all the dependencies installation, building and running the framework; I have then broken it down into the following modules to make it easier to run only parts of the process.

Scaling your API with rate limiters

The following are examples of the four types rate limiters discussed in the accompanying blog post. In the examples below I've used pseudocode-like Ruby, so if you're unfamiliar with Ruby you should be able to easily translate this approach to other languages. Complete examples in Ruby are also provided later in this gist.

In most cases you'll want all these examples to be classes, but I've used simple functions here to keep the code samples brief.

Request rate limiter

This uses a basic token bucket algorithm and relies on the fact that Redis scripts execute atomically. No other operations can run between fetching the count and writing the new count.

Unlocking the Secrets of Rails Secrets and Credentials

If you are like many (most?) of us, you have encountered Rails Credentials/Secrets and secret_key_base and may have been left a bit (or more) confused.

This post is an attempt to remove some of that confusion by

	// Live video stream management for HTML5 video. Uses FFMPEG to connect to H.264 camera stream,
	// Camera stream is remuxed to a MP4 stream for HTML5 video compatibility and segments are recorded for later playback
	var liveStream = function (req, resp) { // handle each client request by instantiating a new FFMPEG instance
	// For live streaming, create a fragmented MP4 file with empty moov (no seeking possible).

	var reqUrl = url.parse(req.url, true)
	var cameraName = typeof reqUrl.pathname === "string" ? reqUrl.pathname.substring(1) : undefined;
	if (cameraName) {
	try {
	cameraName = decodeURIComponent(cameraName);

	# Hello, and welcome to makefile basics.
	#
	# You will learn why `make` is so great, and why, despite its "weird" syntax,
	# it is actually a highly expressive, efficient, and powerful way to build
	# programs.
	#
	# Once you're done here, go to
	# http://www.gnu.org/software/make/manual/make.html
	# to learn SOOOO much more.

	Example infrastructure outage incident report


	Friday, May 13, 2077
	By the Example Security Team


	Earlier this week we experienced an outage in our API infrastructure. Today we’re providing an incident report that details the nature of the outage and our response.
	The following is the incident report for the Example Security outage that occurred on April 30, 2077. We understand this service issue has impacted our valued developers and users, and we apologize to everyone who was affected.

	# frozen_string_literal: true
	class AssociationLoader < GraphQL::Batch::Loader
	attr_reader :klass, :association

	def initialize(klass, association)
	raise ArgumentError, "association to load must be a symbol (got #{association.inspect})" unless association.is_a?(Symbol)
	raise ArgumentError, "cannot load associations for class #{klass.name}" unless klass < ActiveRecord::Base
	raise TypeError, "association #{association} does not exist on #{klass.name}" unless klass.reflect_on_association(association)

	@klass = klass

	FROM golang:1.9

	WORKDIR /go/src/github.com/purplebooth/example
	COPY . .
	RUN go build -ldflags "-linkmode external -extldflags -static" -a main.go

	FROM scratch
	COPY --from=0 /go/src/github.com/purplebooth/example/main /main
	CMD ["/main"]

	ruby '2.7.1'

	gem 'rails', github: 'rails/rails'
	gem 'tzinfo-data', '>= 1.2016.7' # Don't rely on OSX/Linux timezone data

	# Action Text
	gem 'actiontext', github: 'basecamp/actiontext', ref: 'okra'
	gem 'okra', github: 'basecamp/okra'

	# Drivers