vasanthk

System Design Cheatsheet

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

Basic Steps

1. 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?

oelmekki

1. Gemfile

gem 'browserify-rails', '1.5.0' # until fix: https://github.com/browserify-rails/browserify-rails/issues/101
gem 'react-rails'

Browserify-rails allows to use browserify within assets pipeline. React-rails is here only to allow to use #react_component (and thus, prerendering).

Note that jquery-rails can be removed from Gemfile, the npm version of jquery and jquery-ujs will be used instead.

hlxwell

#!/bin/bash
# Interactive PoPToP install script on a OpenVZ VPS
# Tested on Debian 5, 6, and Ubuntu 11.04
# 2011 v1.1
# Author: Commander Waffles
# http://www.putdispenserhere.com/pptp-debian-ubuntu-openvz-setup-script/

echo "######################################################"
echo "Interactive PoPToP Install Script for OpenVZ VPS"
echo "by Commander Waffles http://www.putdispenserhere.com"

tanraya

module CarrierWave
  module MiniMagick
    # Rotates the image based on the EXIF Orientation
    # According to http://jpegclub.org/exif_orientation.html
    def auto_orient
      manipulate! do |image|
        case image['EXIF:Orientation'].to_i
        when 2
          image.flop
        when 3

afeld

Updated for Rails 4.0.0+

Bower

1. Set up the bower gem.

2. Follow the Bower instructions and list your dependencies in your bower.json, e.g.

   // bower.json

{

ivanvanderbyl

sudo add-apt-repository ppa:pitti/postgresql
sudo apt-get update
sudo apt-get install postgresql-9.2 postgresql-server-dev-9.2 postgresql-contrib-9.2

sudo su -l postgres
psql -d template1 -p 5433
CREATE EXTENSION IF NOT EXISTS hstore;
CREATE EXTENSION IF NOT EXISTS "uuid-ossp";
service postgresql stop
/usr/lib/postgresql/9.2/bin/pg_upgrade -b /usr/lib/postgresql/9.1/bin -B /usr/lib/postgresql/9.2/bin -d /var/lib/postgresql/9.1/main/ -D /var/lib/postgresql/9.2/main/ -O "-c config_file=/etc/postgresql/9.2/main/postgresql.conf" -o "-c config_file=/etc/postgresql/9.1/main/postgresql.conf"

shmatov

# lib/tasks/deploy.rake
namespace :deploy do
  desc 'Deploy to staging environment'
  task :staging do
    exec 'mina deploy -f config/deploy/staging.rb'
  end
end

stefanobernardi

class ApplicationController < ActionController::Base
  protect_from_forgery
  
  protected

  def current_user
    @current_user ||= User.find_by_id(session[:user_id])
  end

  def signed_in?

hlxwell

MySQL:  SELECT * FROM user WHERE name = "foobar"Mongo:  db.user.find({"name" : "foobar"})
MySQL:  INSERT INOT user (`name`, `age`) values ("foobar",25)
Mongo:  db.user.insert({"name" : "foobar", "age" : 25})
MySQL:  DELETE * FROM user
Mongo:  db.user.remove({})
MySQL:  DELETE FROM user WHERE age < 30
Mongo:  db.user.remove({"age" : {$lt : 30}})  $gt : > ; $gte : >= ; $lt : < ; $lte : <= ; $ne : !=
MySQL:  UPDATE user SET `age` = 36 WHERE `name` = "foobar"
Mongo:  db.user.update({"name" : "foobar"}, {$set : {"age" : 36}})
MySQL:  UPDATE user SET `age` = `age` + 3 WHERE `name` = "foobar"

shapeshed

upstream app {
	server unix:/srv/app/current/tmp/sockets/unicorn.sock fail_timeout=0;
}
server {
        listen   80;
        server_name  www.app.com;
        rewrite ^/(.*) http://app.com/$1 permanent;
}

server {