1. Ricardo Sanchez
@ricardojsanchez
rsanchez.jayhawk@gmail.com
svDevOps Meetup – August 3, 2010

2.  Operations Architect for PlayHaven
 Started with Ruby/Rails in late 2008
 Networking guy prior to that
• Linux/Unix, kernel+user software development
• C/C++, Routers/Switches, …

3.  ShortRuby Intro
 Ruby projects
 Ruby Lab

4.  Created by Yukihiro “Matz” Matsumoto
 First release 1995, renassaince 2005
 Influenced by Python, Perl, and Lisp
 Focus on simplicity, productivity, and
developer happiness
 Principle of least surprise
 Many interpreters
• MRI, YARV, Jruby, Rubinius, IronRuby, REE, MacRuby,
MagLev, …
 “Rubyist” are
passionate and friendly
people (Culture)

5.  Object-Oriented
 With inheritance, mixins, and metaclasses
 Interpreted
 Dynamic typing and Duck typing
 Everything is an object, no primitives
 and many more “conventions”

6.  Created by DHH (released 2004)
 Web application framework
 Model-View-Controller (MVC) pattern
 Stable 2.3.8, Beta 3.0 RC (just released)
 Principles
• Convention over Configuration (CoC)
• Don‟t Repeat Yourself (DRY)
 REST (Representational State Transfer)

7. Database
Router Controller Model
Model
HTTP Controller Action
Action Action Model
Request
Parameters Action
View
<h2>List of items:
HTTP <% @items.each do |item| %>
Response <li> Item: <%= item %></li>
<% end %>
</h2>

8.  Request made from browser to URL
http://localhost:3000/users/show/1
 Rails receives request on port 3000
• Server invokes dispatcher (routing)
 :controller = users, :action = show, :id = 1
• Action fetches model object from database
• Action renders view which generates HTML
 Rails sends response (HTML page) back

9.  ActiveRecord
 ActionController
 ActionView
 ActionMailer
 ActiveSupport
… is all morphing as Rails3 is introduced

10.  Command line tool
• Install multiple ruby interpreters/versions
 E.g.: ruby (1.8.6-p399, 1.8.7-p187, …); jruby, rubinius
• Manage sets of gems („gemsets‟)
• Perform operations over installed interpreters/gemsets
 Avail for all *nix systems (require „bash‟)
 Quick examples (no sudo needed!)
• $ rvm install ruby-1.9.2, jruby  Install
• $ rvm use 1.9.1  Switching
• $ rvm gemset use rails3  Managing Gems
• $ rvm 1.8.7, 1.9.1, jruby tests  Running tests
• $ rvm 1.8.7, 1.9.1 rake do:all  Running rake task
 http://rvm.beginrescueend.com

11.  Tool for building and distributing
virtualized development environments
 Uses Oracle‟s VirtualBox
 Main features
• Automated provisioning using chef
• Forward port to host machine
• Full SSH access to created environments
• Shared folders between host/guest(s)
• Package environments into distributable boxes
 Great for distributable dev/qa environments
 To install: # gem install vagrant
 http://vagrantup.com

12.  Task automation tool on remote servers
 Features
• Restart particular service on multiple servers once
 $ cap HOSTS=„www-1,www-2‟
COMMAND=„/etc/init.d/apache2 restart” invoke
• Check state of service/resource (memory,cpu) that is not
monitored
 $ cap HOSTS=„www-1,www-2‟ COMMAND=„grep MemTotal
/proc/meminfo‟ invoke
• Run command in multiple servers and monitor output
• Systems deployment tasks (e.g., Rails deployments)
 To install: # gem install capistrano
 http://capify.org

13.  Problem: how to manage many servers
 Solution: consolidate access to infrastructure data for
all nodes („systems integration‟)
 Chef provides configuration, integration, and
operations as code (written in Ruby)
• Treat infrastructure like software development projects
 Modes: solo, client/server
 Concepts
• Nodes, Roles, Cookbooks, Recipes, Resources, Attributes
 Opscode offerings
• Chef - Server Configuration Management Tool (API & DSL)
• Opscode Platform (hosted chef server)
 http://www.opscode.com

14.  Books
• Programming Ruby 1.9
• The Ruby Programming Language
• Practical Ruby for Systems Administration
• Everyday Scripting with Ruby
 Online Learning
• http://rubylearning.org (Free course)
• http://github.com/edgecase/ruby_koans (FUN)
 Blogs
• http://rubyinside.com
• http://rubyflow.com

15.  Installation (all platforms)
• http://www.wiki.devchix.com/index.php?title=Work
shop_Installation_Notes
 Ruby, RubyGems
 Editor (your choice)
 Exercise
• Open irb
 $ irb
 >> puts “Hello world”
• Save previous line on hello.rb, chmod +x, and run
 $ ruby hello.rb