The Great API Redesign (API Conference 2018)

Redesigning a public web service API is a major undertaking: 3 years, thousands of hours of work, new clients, new documentation, a series of releases… This is the story of the DNSimple API v2, a project that started with a single, innocuous GitHub pull request with the title "Proposal for versioned API" in December 2013, and which came to a successful general availability launch at the end of 2016. Simone will explain some of the decisions that the team took over the last 3 years that shaped the development of the API as well as challenges the team faced, and provide you with tips and techniques that may help you in your next major API project. Finally, the important question: what’s next?

Transcript

1. The Great API Redesign
   Simone Carle7, DNSimple
   

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3. @weppos
   

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5. "This PR is a first step towards API versioning and
   using a dedicated hostname for API."
   

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6. "This PR is a first step towards API versioning and
   using a dedicated hostname for API."
   Dec 28, 2013
   

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7. Dec 28, 2013
   v0
   API v0
   

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8. API v0
   • Same hostname as website
   • No versioning
   • No metrics
   • Shared Rails controllers
   

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9. It worked ™
   

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10. GET https://dnsimple.com/domains.json
    GET https://dnsimple.com/domains.json
    

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11. Jan 14, 2014
    Dec 28, 2013
    v0 v1
    API v1
    

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12. API v1
    • Introduce hostname api.dnsimple.com
    • Introduce path-based versioning
    • SFll uses the same Rails controllers
    • Simple transiFon through minimal changes
    

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13. GET https://api.dnsimple.com/v1/domains
    

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14. Why a separate hostname?
    • Easily flag requests as API requests
    • Improved error handling due to clear indicaFon of what
    is an API call
    • Adds the ability to extract API code from controllers
    • Provides easier scaling
    

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15. Why path-based versioning?
    The approach I followed is simple.
    May be not the most restful, but it's the one very
    commonly adopted that will also allow us to
    switch to a mime-based approach (in case we
    want to follow that route in the future).
    

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16. Why path-based versioning?
    • API version is embedded in the path and it prefixes the URL
    • Everything in the URL is easily visible in logs
    • Easiest implementaFon for both producFon and
    consumpFon
    • HiSng path-based versioned APIs with a browser is easy
    • New versions increase the major number
    • Path and verb changes can be introduced at major version
    

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17. Jan 14, 2014
    Dec 28, 2013
    v0 v1
    API v1
    

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18. Jan 14, 2014
    Dec 28, 2013
    v0 v1 v2
    API v2
    

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19. Separate ApplicaIon
    • Use of a separate
    (sub)applicaFon
    • No longer Fghtly coupled to
    the Rails controllers
    hWp:/
    /hanamirb.org
    hWp:/
    /confreaks.tv/videos/railsconf2016-developing-and-maintaining-a-pla\orm-with-rails-and-lotus
    

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20. the Roadmap
    • MulF-account
    • Reusable shared business logic
    • Response serializaFon
    • PaginaFon, SorFng and Filtering
    • AuthenFcaFon
    • Rate limiFng
    • Webhooks
    • API clients
    

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23. May 2, 2016
    API clients
    Java PHP
    May 2, 2016 Sep 6, 2016 Sep 13, 2016
    hWps:/
    /slidr.io/weppos/using-go-to-guide-api-design-decisions-dotgo-2016
    

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24. API clients
    • Developing clients gets easier with each new client
    • Common design paWerns emerge
    • Shared HTTP fixtures
    • We built a foundaFon for API clients development
    hWps:/
    /blog.dnsimple.com/2017/01/api-client-tesFng-with-hWp-fixtures/
    

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25. PrioriIes
    • Gathered metrics on v1 endpoint usage
    • PrioriFzed implementaFon based on usage
    

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26. Jan 14, 2014 Mar 9, 2016 (Beta)
    Dec 13, 2016 (GA)
    Dec 28, 2013
    v0 v1 v2
    API v2
    

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27. Stats
    • 717 Days from "Start" to "Finish"
    • 3 (almost) full-Fme team members out of 11 total, with a
    collaboraFve effort from the enFre DNSimple team
    • 4 official API clients, with 2 more under development
    • 75 API methods currently available (*)
    • 251 Ickets across 7 major milestones
    • ~423 API related support Ickets handled in the last year
    • ~1934 commits across the 4 API clients and applicaFon
    

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28. What's next?
    • Adopt a formal language to describe the API
    • Deprecate and shut down API v1
    • Facilitate transiFon to API v2
    • Implement new methods (e.g. cerFficate, pricing)
    

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29. Open API
    hWps:/
    /www.openapis.org/
    

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30. hWps:/
    /blog.dnsimple.com/2018/02/openapi/
    

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31. hWps:/
    /blog.dnsimple.com/2018/04/openapi-in-depth/
    

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33. TransiIon to v2
    Measure Facilitate Deprecate
    

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34. TransiIon to v2
    Measure Facilitate
    Deprecate
    

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35. TransiIon to v2
    Measure Facilitate
    Deprecate
    

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36. TransiIon to v2
    Measure Facilitate
    Deprecate
    

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37. TransiIon to v2
    Measure Facilitate
    Deprecate
    

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38. TransiIon to v2
    Measure Facilitate
    

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39. Lessons
    • Simple transiFon through minimal changes
    • Be a producer and a consumer
    • Provide official clients (and/or contribute)
    • Measure decisions
    • Invest into the API
    

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40. Thanks!
    Simone Carle7 /
    / DNSimple
    hWps:/
    /slidr.io/weppos
    @weppos
    

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