Alexander Yunin sagebomb

Rails Models

Generating models

$ rails g model User

Associations

belongs_to

has_one

Ubuntu 12.10 setup (rbenv/RVM, Janus, PostgreSQL)

Basic pre-requisites

Some utilities:

sudo apt-get install vim tmux git curl

Copy/paste from the command line:

Zero downtime deploys with unicorn + nginx + runit + rvm + chef

Below are the actual files we use in one of our latest production applications at Agora Games to achieve zero downtime deploys with unicorn. You've probably already read the GitHub blog post on Unicorn and would like to try zero downtime deploys for your application. I hope these files and notes help. I am happy to update these files or these notes if there are comments/questions. YMMV (of course).

Other application notes:

Our application uses MongoDB, so we don't have database migrations to worry about as with MySQL or postgresql. That does not mean that we won't have to worry about issues with the database with indexes being built in MongoDB or what have you.
We use capistrano for deployment.

Salient points for each file:

	- http://www.coffeepowered.net/2009/06/13/fine-tuning-your-garbage-collector/
	- http://snaprails.tumblr.com/post/241746095/rubys-gc-configuration

	article’s settings: ("spec spec" took 17-23!sec)
	export RUBY_HEAP_MIN_SLOTS=1250000
	export RUBY_HEAP_SLOTS_INCREMENT=100000
	export RUBY_HEAP_SLOTS_GROWTH_FACTOR=1
	export RUBY_GC_MALLOC_LIMIT=30000000
	export RUBY_HEAP_FREE_MIN=12500

	#!/bin/bash -e
	#
	# Since unicorn creates a new pid on restart/reload, it needs a little extra love to
	# manage with runit. Instead of managing unicorn directly, we simply trap signal calls
	# to the service and redirect them to unicorn directly.
	#
	# To make this work properly with RVM, you should create a wrapper for the app's gemset unicorn.
	#

	function is_unicorn_alive {

	# app/models/ability.rb

	# All front end users are authorized using this class
	class Ability
	include CanCan::Ability

	def initialize(user)
	user \|\|= User.new

	can :read, :all

	# coding: utf-8
	require 'sinatra'
	set server: 'thin', connections: []

	get '/' do
	halt erb(:login) unless params[:user]
	erb :chat, locals: { user: params[:user].gsub(/\W/, '') }
	end

	get '/stream', provides: 'text/event-stream' do

	package main

	import (

	"log"
	"net/mail"
	"encoding/base64"
	"net/smtp"
	"fmt"
	"strings"

	class TracePoint
	class Middleware

	def initialize(app)
	@app = app
	end

	def call(env)
	stats = {}
	trace = TracePoint.new(:call) do \|tp\|