Cloudstock 2010 Presentation

1. JRuby, Ruby, Rails and You
on the Cloud
December 6th, 2010

2. Who am I?
Hiro Asari
• JRuby Support Engineer at Engine Yard
• hasari@engineyard.com
2

3. Engine Yard
• Platform as a Service provider
• Ruby on Rails specialists
• http://www.engineyard.com
3

4. http://thenetworkisthecomputer.com/
4

5. WHAT IS RUBY ON RAILS?"
AND"
WHY RUBY ON RAILS?
http://www.flickr.com/photos/88019192@N00/3277925689/
5

6. JVM Web Frameworks Surveys
• http://bit.ly/jvm-frameworks-matrix
• http://bit.ly/webmatrixsurveyresults
6

7. Rails
ü Is a web application
framework written in Ruby
http://www.flickr.com/photos/46799485@N00/4386602878
7

8. Ruby quick facts
• Conceived by Yukihiro
Matsumoto (a.k.a. Matz)
in 1993
• Object-oriented
dynamically-typed
interpreted scripting
language
• Influenced by Perl,
Smalltalk, Eiffel and LISP
• External libraries are
most frequently
distributed as “gems”
8

9. Rails quick facts
• Conceived by David
Heinemeier Hansson
(a.k.a. DHH) in 2004
• Extracted from 37signals’
“Basecamp” application
• Uses MVC design
pattern
• Rails 3, released in
August, 2010, uses
“Bundler” to manage
gems.
9

10. Who uses Rails?
10

11. Getting JRuby
http://jruby.org
11

12. NetBeans
http://netbeans.org
12

13. NetBeans (if you have it already)
13

14. RubyMine
http://jetbrains.com/ruby
14

15. RVM (Ruby Version Manager)
• http://rvm.beginrescueend.com/
• rvm install jruby
• rvm use jruby
15

16. Rails
ü Gets you off and running
quickly
16

17. 17

18. jruby -S rails new cloudstock_demo
cd cloudstock_demo
vi Gemfile
jruby -S bundle install
jruby -S bundle exec glassfish
18

19. $ jruby -S rails new cloudstock_demo -m http://jruby.org
create
create README
create app
create app/controllers/application_controller.rb
create app/helpers/application_helper.rb
create app/mailers
create app/models
create app/views/layouts/application.html.erb
create public
create public/404.html
create script/rails
create test
create test/fixtures
create test/test_helper.rb
create test/unit
apply http://jruby.org
apply http://jruby.org/templates/default.rb
gsub Gemfile
19

20. 20

21. $ jruby script/rails generate scaffold user name:string
calling init (1017e6ac0)
invoke active_record
create db/migrate/20101115150436_create_users.rb
create app/models/user.rb
invoke test_unit
create test/unit/user_test.rb
create test/fixtures/users.yml
route resources :users
invoke scaffold_controller
create app/controllers/users_controller.rb
invoke erb
create app/views/users
create app/views/users/index.html.erb
create app/views/users/edit.html.erb
create app/views/users/show.html.erb
create app/views/users/new.html.erb
create app/views/users/_form.html.erb
invoke test_unit
create test/functional/users_controller_test.rb
invoke helper
create app/helpers/users_helper.rb
invoke test_unit
create test/unit/helpers/users_helper_test.rb
invoke stylesheets
create public/stylesheets/scaffold.css
21

22. $ cat db/migrate/20101115150436_create_users.rb
class CreateUsers < ActiveRecord::Migration
def self.up
create_table :users do |t|
t.string :name
t.timestamps
end
end
def self.down
drop_table :users
end
end
22

23. Rails
ü Is descriptive
23

24. class User < ActiveRecord::Base
validates_length_of :name, :minimum => 5
end
24

25. Rails
ü Is tested
25

26. $ find test
test
test/fixtures
test/fixtures/users.yml
test/functional
test/functional/users_controller_test.rb
test/integration
test/performance
test/performance/browsing_test.rb
test/test_helper.rb
test/unit
test/unit/helpers
test/unit/helpers/users_helper_test.rb
test/unit/user_test.rb
26

27. $ cat test/unit/user_test.rb
require 'test_helper'
class UserTest < ActiveSupport::TestCase
test "bare user is invalid" do
u = User.new
assert !u.valid?
assert u.errors[:name].any?
end
test "user with name shorter than 5 character is invalid" do
u = User.new(:name => "hi")
assert !u.valid?
assert u.errors[:name].any?
end
test "user with name with at least 5 character is valid" do
u = User.new(:name => "hello")
assert u.valid?
end
end
27

28. Rails
ü Is good for agile
development
28

29. Rails
ü Makes you happy
29

30. WHAT ABOUT…
30

31. Accessing Java library from Rails
• Generating SVG with Batik
• http://xmlgraphics.apache.org/batik/
31

32. Example 1: Generating SVG with Batik
require 'java'
require 'batik'
java_import org.apache.batik.svggen.SVGGraphics2D
java_import org.apache.batik.dom.GenericDOMImplementation
dom = GenericDOMImplementation.getDOMImplementation
svg_ns = 'http://www.w3.org/2000/svg'
doc = dom.createDocument svg_ns, 'svg', nil
svg_gen = SVGGraphics2D.new( doc )
svg_gen.set_paint java.awt.Color.send(color)
svg_gen.fill java.awt.Rectangle.new(10,10,100,100)
svg_gen.set_paint java.awt.Color.send(text_color)
svg_gen.draw_string @user.name, 25, 55
out = java.io.StringWriter.new
svg_gen.stream(out, true)
render :inline => out.to_string
32

33. Accessing Java library from Rails
• Generating PDF with iText
• http://itextpdf.com/
33

34. Example 2: Generating PDF with iText
require 'iText-5.0.5'
pdf = com.itextpdf.text.Document.new
para = com.itextpdf.text.Paragraph.new "Hello #{@user.name}"
file = "#{::Rails.root.to_s}/tmp/pdfs/pdf_demo.pdf”
out = java.io.FileOutputStream.new file
com.itextpdf.text.pdf.PdfWriter.get_instance pdf, out
pdf.open
pdf.add para
pdf.close
render :file => file
Don’t do this in production code!
34

35. JRuby on Engine Yard AppCloud
35

36. JRuby on Engine Yard AppCloud — Sign up today!
http://docs.engineyard.com/beta/home
36

37. Testing in more detail
• RSpec http://rspec.info
• Cucumber http://cukes.info
• Celerity http://celerity.rubyforge.org
37

38. Deployment strategies
• Glassfish http://glassfish.java.net/ (.WAR)
• Tomcat http://tomcat.apache.org/ (.WAR)
• JBoss http://jboss.org/ (.WAR)
• Jetty http://jetty.codehaus.org/jetty/ (.WAR)
• Glassfish gem http://rubyforge.org/projects/glassfishgem/ (embedded
glassfish)
• Trinidad https://github.com/calavera/trinidad (embedded Tomcat)
• Torquebox http://torquebox.org/ (embedded JBoss with extras)
• Google App Engine http://code.google.com/appengine/ (via google-
appengine gem http://code.google.com/p/appengine-jruby/)
• Mongrel (outdated)
38

39. Further information
• The Ruby language web site http://ruby-lang.org
• Ruby On Rails web site http://rubyonrails.org
• JRuby web site http://jruby.org
• Engine Yard web site http://engineyard.com
• Using JRuby (Pragmatic Bookshelf)
http://www.pragprog.com/titles/jruby/using-
jruby
• Meet Rails 3 (Peep Code)
https://peepcode.com/products/meet-rails-3-i
39

40. Zero to Rails 3
• http://www.engineyard.com/sparkle
• 4-day online training (December 20-23)
40

41. http://www.flickr.com/photos/10485077@N06/4975546097
41

42. Thank you!
Contact me
hasari@engineyard.com
Twitter: @hiro_asari
Github: BanzaiMan
http://www.flickr.com/photos/42033648@N00/372887164
42