Alex Le sr3d

Coding Rails with Homebrew

Right now, this assumes you are using Snow Leopard.

Install Homebrew

Homebrew is MacPorts (or APT) without the suck. http://github.com/mxcl/homebrew

Friendly URLs

By default, Rails applications build URLs based on the primary key -- the id column from the database. Imagine we have a Person model and associated controller. We have a person record for Bob Martin that has id number 6. The URL for his show page would be:

/people/6

But, for aesthetic or SEO purposes, we want Bob's name in the URL. The last segment, the 6 here, is called the "slug". Let's look at a few ways to implement better slugs.

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.

	require 'rubygems'
	require 'eventmachine'
	require 'evma_httpserver'
	require 'cgi'

	class Room < EM::Channel
	end

	$room = Room.new
	$welcome_html = DATA.read

	# Author: Pieter Noordhuis
	# Description: Simple demo to showcase Redis PubSub with EventMachine
	#
	# Requirements:
	# - rubygems: eventmachine, thin, cramp, sinatra, yajl-ruby
	# - a browser with WebSocket support
	#
	# Usage:
	# ruby redis_pubsub_demo.rb
	#

	require 'digest/md5'

	def gfm(text)
	# Extract pre blocks
	extractions = {}
	text.gsub!(%r{<pre>.*?</pre>}m) do \|match\|
	md5 = Digest::MD5.hexdigest(match)
	extractions[md5] = match
	"{gfm-extraction-#{md5}}"
	end

	# Install with:
	# bash < <(curl -L https://raw.github.com/gist/1754122)
	#
	# Reference: http://blog.wyeworks.com/2011/11/1/ruby-1-9-3-and-ruby-debug
	#
	# Update to work with the falcon patch.

	echo "Installing ruby-debug with ruby-1.9.3-p0 ..."

	curl -OL http://rubyforge.org/frs/download.php/75414/linecache19-0.5.13.gem

	#
	# Wide-open CORS config for nginx
	#
	location / {

	if ($request_method = 'OPTIONS') {

	add_header 'Access-Control-Allow-Origin' '*';

	#

	##################################################################
	# /etc/elasticsearch/elasticsearch.yml
	#
	# Base configuration for a write heavy cluster
	#

	# Cluster / Node Basics
	cluster.name: logng

	# Node can have abritrary attributes we can use for routing

	# Basic Dante Socks5 Setup, Debian

	apt-get update
	apt-get install make gcc

	cd /usr/src

	# get newest from http://www.inet.no/dante/download.html

	wget http://www.inet.no/dante/files/dante-1.4.1.tar.gz