This document summarizes a talk about using Sinatra and RestClient for building lightweight web services and clients. Sinatra provides a simple and lightweight way to build web applications compared to full-featured frameworks like Rails. RestClient provides a simple way to make HTTP requests from client applications, offering more functionality than Net::HTTP but with less complexity than ActiveResource. Examples of Sinatra and RestClient use include a Git wiki application built in 355 lines of Ruby code and a Heroku client library.

1. Lightweight web services
with Sinatra and RestClient
Adam Wiggins &
Blake Mizerany
Rubyconf 2008

2. What for?

3. app lifecycle

4. Birth: small and beautiful

5. Fate: sprawling mess

6. web services

7. Rails?

8. Rails?
Too much.

9. Bare mongrel handler or
Rack app?

10. Bare mongrel handler or
Rack app?
Too little.

11. Sinatra - the classy
microframework for
Ruby

12. require 'rubygems'
require 'sinatra'
get '/' do
quot;Hello, whirledquot;
end

13. $ ruby hello.rb

14. require 'rubygems'
require 'sinatra'
require 'lib/posts'
post '/posts'
post = Post.create! params
redirect quot;/posts/#{post.id}quot;
do
get '/posts/:id' do
@post = Post.find(params[:id])
erb :post
end

15. ‣Templating (erb, haml, builder)
‣Tests/specs (test/spec, rspec, test::unit)
‣Before filters
‣Helpers
‣Error handlers
‣Inline templates
‣Code reloading
‣HTTP caching (etag, last-modified)
‣Rack / inline middleware

16. A commitment to small

17. A commitment to small
Rails 87,990
Merb-core 12,417
Ramaze 11,796
Camping 1,704
Sinatra 1,576

18. Sinatra is a proud
Ruby citizen

19. examples

20. git-wiki
http://github.com/sr/git-wiki
355 lines
of Ruby

21. get '/:page' do
@page = Page.find(params[:page])
haml :show
end
__END__
@@ layout
%html
%body
%content=yield
@@ show
%h1= title
#page_content= @page.to_html

22. rifgraf
http://github.com/adamwiggins/rifgraf
61 lines
of Ruby

23. github-services
http://github.com/pjhyett/github-services
423 lines
of Ruby

24. scanty
http://github.com/adamwiggins/scanty
194 lines
of Ruby

25. client side

26. ActiveResource?

27. ActiveResource?
Too much.

28. Net::HTTP?

29. Net::HTTP?
Too little.

30. RestClient -
the Sinatra-inspired
microclient for Ruby

31. require 'rubygems'
require 'rest_client'
RestClient.get 'http://localhost:4567/posts'

32. require 'rubygems'
require 'rest_client'
RestClient.post 'http://localhost:4567/posts',
:author => 'Me', :title => 'First Post'

33. Console
$ restclient http://example.com
>> post '/resource', :value => 42
=> quot;resultquot;

34. A better curl
$ restclient get http://example.com/posts > posts.xml
$ restclient post http://example.com/posts < post.xml
$ restclient put http://example.com/posts/1 < post.xml
$ restclient delete http://example.com/posts/1

35. Logging & replay
$ RESTCLIENT_LOG=stdout ruby myscript.rb
RestClient.get quot;http://example.com/postsquot;
# => 200 OK | text/html 3781 bytes
RestClient.post quot;http://example.com/postsquot;,
quot;title=First+postquot;
# => 200 OK | text/html 40 bytes

36. examples

37. heroku-client
http://github.com/adamwiggins/heroku-client

38. couchrest
http://github.com/jchris/couchrest

39. principles

40. “lagom”

41. “lagom”
just the right amount

42. Fewer classes,
less inheritance

43. Controller object
mapping & routes
vs.
URLs

44. Controller object s !
RL
mapping & routes U e
r th
fea
vs.
n ’t
o
URLs
D

45. Exposed simplicity
instead of
hidden complexity

46. Small things,
loosely joined,
written fast
- Justin Gehtland @ Relevance

47. http://github.com/bmizerany/sinatra
http://rest-client.heroku.com/
http://adam.blog.heroku.com/
Adam Wiggins &
Blake Mizerany
Rubyconf 2008