Api Builder - Scala Up North 2017

July 21, 2017
Scala Up North
Vancouver BC
#scala #apibuilder #rest #canada

Transcript

1. Sean Sullivan July 21, 2017 Scala Up North
2. • software engineer • 21 years on the JVM • back office systems @ HBC About me
3. https://en.wikipedia.org/wiki/Hudson%27s_Bay_Company
5. saksfifthavenue.com saksoff5th.com lordandtaylor.com gilt.com thebay.com
6. API driven development
7. API descriptors
8. API descriptors are not a new concept
9. • 2000: WSDL 1.0 (SOAP) • 2006: WADL (REST) • 2011: Swagger (REST) • 2014: ApiDoc (REST) • 2017: ApiDoc rebranded to ApiBuilder
10. www.apibuilder.io
12. describe REST API in a JSON file
13. 1. start by describing your models 2. map your models to resources
14. "models": { "credit_card": { "fields": [ { "name": "guid", "type": "uuid" }, { "name": "user_guid", "type": "uuid" }, { "name": "type", "type": "credit_card_type" }, { "name": "issuer", "type": “string", “required": false }, { "name": "last_four", "type": "string" }, { "name": "expire_date", "type": "string" }, { "name": "billing_address", "type": "address" } ] } }
15. "resources": { "credit_card": { "operations": [ { "method": "GET", "path": "/:guid", "description": "Get a credit card.", "responses": { "200": { "type": "credit_card" }, "404": { "type": “unit”, "description": "Card not found." } } } }
16. gilt.com
17. www.gilt.com
18. • Rails app • one Git repo • monolith! Gilt: 2007 => 2008
19. • Rails app • JSP web framework • ~10 services (Java) • handcrafted Java clients • weak typing (java.util.HashMap) Gilt: 2009 => 2010
20. • JSP’s • 100+ services (Java, Scala) • strongly typed client libraries • Gilt “Commons” library Gilt: 2011 => 2013
21. • Gilt Commons library • 250+ services • binary coupling • dependency hell • ApiBuilder project started on Github Gilt: 2014
22. Dependency hell Java runtime hell
23. • java.lang.NoClassDefFoundError • java.lang.NoSuchFieldError • java.lang.NoSuchMethodError Java runtime hell
24. Dependency hell kills productivity
26. Mitigating dependency hell • API design must be first class • backwards and forward compatibility • accurate documentation • generated client libraries
27. • 350+ services • new services built with ApiBuilder + generated clients • Gilt Commons library is deprecated Gilt: 2015 => 2017
28. Web Checkout Android Checkout iPhone Checkout Checkout service api.json
29. Generating client libraries with ApiBuilder
30. Code generators
32. Scala client generators • Http4s + Circe JSON • Ning AsyncHttpClient {1.8, 1.9} • Play WS {2.2, 2.3, 2.4, 2.5, 2.6}
34. Conclusion • API driven development • visit www.apibuilder.io
35. The end
37. Bonus material
38. Gilt 2015