Inspirações de outras linguagens: Um conjunto de ferramentas Ruby (relativamente) novo

Sempre que queremos criar um projeto novo ou adicionar novas features a algo já um já existente, queremos descobrir algo diferente ou que atenda melhor nossas necessidades. Tivemos uma oportunidade destas na Locaweb ao começar o projeto 'Hightower', que consistia em remover dados de clientes do SAP, embora a tecnologia escolhida tenha sido Java, acabei descobrindo uma série de ferramentas novas que podem ser utilizadas em projetos Ruby. Gostaria nesta talk de apresentar duas ferramentas(gems)/conceitos que achei interessantes, Dry-Auto_Inject e Stoplight.

Transcript

1. Other languages inspirations Some new Ruby gems
4. 1. About me Gabriel Malaquias de Souza. ➔ Locaweb - Enterprise Applications Since 2015 ➔ Analysis and Systems development Fatec Zona Leste - 2015 ➔ Blog gabrielmalakias.com.br
5. Why?
8. 2. Schedule ➔ Dependency Injection Using Dry-Auto_Inject and Dry-Container ➔ Circuit-Breaker Using Stoplight
10. So, let’s talk about dependency injection... Ps:. But it’s not something really new.
11. 3. An example https://dzone.com/articles/dependency-injection-0
12. @Autowired
13. 4. Spring @Component public class CreateArticle { private final ArticleRepository repository; @Autowired public CreateArticle(ArticleRepository repository) { this.repository = repository; }
14. 5. Ruby class CreateArticle attr_reader :repository def initialize(repository = ArticleRepository.new) self.repository = repository; end
15. dry-rb/dry-container
16. 6. Dry-Container class Blog::Container extend Dry::Container::Mixin register('commands.article.create') do Commands::Article::Create.new end end AutoInject = Dry::AutoInject(Blog::Container)
17. dry-rb/dry-auto_inject
18. 7. Dry-Auto_inject class CreateArticle include AutoInject[repository: 'repository.article'] def call(article) repository.call(article) end end
19. And how can we test it?
20. 8. Testing my_obj = CreateArticle.new(repository: double(ArticleRepository))
22. But now, let’s talk about good things… TecPix?
23. No, we are going to talk about Circuit Breaker...
24. About Hystrix You can support graceful degradation in a Hystrix command by adding a fallback method that Hystrix will call to obtain a default value or values in case the main command fails. - Github Project Page
25. 9. Hystrix public class CommandHelloFailure extends HystrixCommand<String> { @Override protected String run() { throw new RuntimeException("fail"); } @Override protected String getFallback() { return "Hello Failure " + name + "!"; } }
26. Ruby CircuitBreaker options • wsargent/circuit_breaker; • pedro/cb2; • yammer/circuitbox; • jnunemaker/resilient;
27. orgsync/stoplight
28. 10. How it works?
29. 11. How it works?
30. 12. Another Example irb(main):001:0> lambda = -> { puts "Hello World!" } => #<Proc:(irb):1 (lambda)> irb(main):002:0> light = Stoplight('example') { lambda.call }
31. 13. Running It irb(main):003:0> light.run Hello World! => nil irb(main):004:0> light.run Hello World! => nil irb(main):005:0> light.color => "green"
32. 14. A failure example light = Stoplight('call') { raise StandardError } .with_fallback{|_| 'Fallback' } .with_cool_off_time(3)
33. 15. Running It irb(main):012:0> light.run => “Fallback” irb(main):015:0> light.color => "red" irb(main):016:0> sleep(3) irb(main):017:0> light.color => "yellow"
34. 16. The Stoplight data store require 'stoplight' require 'redis' redis = Redis.new(host: ENV["REDIS"]) Stoplight::Light.default_data_store = Stoplight::DataStore::Redis.new(redis)
35. Can we use commands like using Hystrix?
36. 17. Creating a command def fallback(id) ::Article.new end def find(id) // It can raise an Exception end def custom_error_handler(error, handle) raise error if error.is_a?(RecordNotFound) handle.call(error) end
37. 18. Creating a command class Commands::Article::Find def call(id) Stoplight('article.find') do find(id) end.with_fallback do |error| fallback(id) end.with_error_handler do |error, handle| custom_error_handler(error, handle) end.run end
38. Customizing notifiers
39. 19. Creating a custom notifier module Notifiers class Custom < Stoplight::Notifier::Base def notify(light, from_color, to_color, error) puts("[Custom] - Light: #{light.inspect}”) end end end
40. 20. Adding it Stoplight::Light.default_notifiers += Array(Notifiers::Custom.new)
41. STAY CURIOUS and KEEP LEARNING
42. We always have different ways
43. References https://github.com/Netflix/Hystrix http://electronics.howstuffworks.com/circuit-breaker2.htm https://github.com/orgsync/stoplight https://github.com/jnunemaker/resilient https://github.com/yammer/circuitbox https://www.infoq.com/br/presentations/exercising-failur e-at-netflix#downloadPdf
44. References http://dry-rb.org/; http://trailblazer.to/gems/operation/1.1/; http://www.martinfowler.com/articles/injection.html; http://solnic.eu/2013/12/17/the-world-needs-another-po st-about-dependency-injection-in-ruby.html; https://en.wikipedia.org/wiki/Dependency_inversion_princ iple.
45. Thank You!