Fast, testable and sane APIs - RubyC.eu Kiev 2014

By now, we've all written JSON APIs in Rails. But how do you write fast, testable and sane APIs? I'll guide you through the trials of designing and building awesome, scalable APIs. We'll cover Rails-API, ActiveModel::Serializers, and all the heavenly goodness our ecosystem has to offer.

Transcript

1. Fast, testable and SANE APIs Ben Lovell
7. I ❤️ Kyiv
13. _benlovell
14. benlovell j
19. “I HAVE KILLED, AND I WILL KILL AGAIN”
31. Building JSON APIs awesome!
32. Rails-API
33. JSON API BIKESHEDDING
34. ActiveModel::Serializers because #to_json kinda sucks
35. HTTP it’s all about the semantics
36. /etc too meta to categorise
38. Components of good API design
39. FAST STANDARDISED INTUITIVE
40. FAST STANDARDISED INTUITIVE
41. FAST STANDARDISED INTUITIVE
42. JSON API
45. application/vnd.api+json IANA registered
46. WIP! http://git.io/Uh8Y8w
47. { "links": { "posts.author": { "href": "http://example.com/people/{posts.author}", "type": "people" }, "posts.comments": { "href": "http://example.com/comments/{posts.comments}", "type": "comments" } }, "posts": [{ "id": "1", "title": "Rails is Omakase", "links": { "author": "9", "comments": [ "5", "12", "17", "20" ] } }] }
48. { "posts": [{ "id": "1", "title": "Rails is Omakase", "links": { "author": "9", "comments": [ "5", "12", "17", "20" ] } }] }
49. { "posts": [{ "id": 1 // a post document }] } { }, { }] } Singular Resource Resource Collection
50. { }] } { "posts": [{ "id": 1 // a post document }, { "id": 2 // a post document }] } Singular Resource Resource Collection
51. { "posts": [{ "id": "1", "title": "Rails is Omakase", "links": { "comments": [ "5", "12", "17", "20" ] } }] } To-Many Relationships
52. { "posts": [{ "id": "1", "title": "Rails is Omakase", "links": { "comments": { "href": "http://example.com/comments/5,12,17", "ids": [ "5", "12", “17" ], "type": "comments" } } }] } To-Many Relationships (link style)
53. { "links": { "posts.comments": "http://example.com/posts/{posts.id}/comments" }, "posts": [{ "id": "1", "title": "Rails is Omakase" }, { "id": "2", "title": "The Parley Letter" }] } Shorthand (link style) RFC6570 URI Template
58. /etc I did warn you
59. COMPOUND DOCUMENTS the fastest HTTP is no HTTP
60. GET /posts/1?include=comments GET /posts/1?include=comments.author GET /posts/1?include=author,comments
61. { "links": { "posts.author": { "href": "http://example.com/people/{posts.author}", "type": "people" }, "posts.comments": { "href": "http://example.com/comments/{posts.comments}", "type": "comments" } }, "posts": [{ "id": "1", "title": "Rails is Omakase", "links": { "author": "9", "comments": [ “1" ] }}], "linked": { "authors": [{ "id": "9", "name": "@dhh" }], "comments": [{ "id": "1", "body": "Mmmmmakase" }] } }
62. SPARSE FIELDSETS
63. GET /posts/1?fields=id,title,body
64. HTTP SEMANTICS
66. wat
72. RAILS-API
73. ❤️
74. Ruby is not as slow as you might think…
75. Ruby is not as slow as you might think… …IT’S SLOWER
76. So, how do we make Ruby fast?
77. By running less Ruby. DERP! So, how do we make Ruby fast?
78. So, how do we make Rails fast?
79. So, how do we make Rails fast? By running less Rails. DERP!
80. YO DAWG! I heard you like rails so I took some rails out of your rails so you could rails (a little bit faster than usual)
81. use Rack::Sendfile use ActionDispatch::Static use Rack::Lock use #<ActiveSupport::Cache::Strategy::LocalCache::Middleware> use Rack::Runtime use Rack::MethodOverride use ActionDispatch::RequestId use Rails::Rack::Logger use ActionDispatch::ShowExceptions use ActionDispatch::DebugExceptions use ActionDispatch::RemoteIp use ActionDispatch::Reloader use ActionDispatch::Callbacks use ActiveRecord::Migration::CheckPending use ActiveRecord::ConnectionAdapters::ConnectionManagement use ActiveRecord::QueryCache use ActionDispatch::Cookies use ActionDispatch::Session::CookieStore use ActionDispatch::Flash use ActionDispatch::ParamsParser use Rack::Head use Rack::ConditionalGet use Rack::ETag run KitchenSinkFullOfKitchenSinks::Application.routes
83. use Rack::Sendfile use ActionDispatch::Static use Rack::Lock use #<ActiveSupport::Cache::Strategy::LocalCache::Middleware> use Rack::Runtime use Rack::MethodOverride use ActionDispatch::RequestId use Rails::Rack::Logger use ActionDispatch::ShowExceptions use ActionDispatch::DebugExceptions use ActionDispatch::RemoteIp use ActionDispatch::Reloader use ActionDispatch::Callbacks use ActiveRecord::Migration::CheckPending use ActiveRecord::ConnectionAdapters::ConnectionManagement use ActiveRecord::QueryCache use ActionDispatch::Cookies use ActionDispatch::Session::CookieStore use ActionDispatch::Flash use ActionDispatch::ParamsParser use Rack::Head use Rack::ConditionalGet use Rack::ETag run KitchenSink::Application.routes
85. require “rails/all”
86. require “rails/all”
87. irb(main):003:0> pp ActionController::API.ancestors - ActionController::Metal.ancestors [ ActionController::API, ActiveRecord::Railties::ControllerRuntime, ActionDispatch::Routing::RouteSet::MountedHelpers, ActionController::StrongParameters, ActionController::Instrumentation, ActionController::Rescue, ActiveSupport::Rescuable, ActionController::DataStreaming, ActionController::ForceSSL, AbstractController::Callbacks, ActiveSupport::Callbacks, ActionController::ConditionalGet, ActionController::Head, ActionController::Renderers::All, ActionController::Renderers, ActionController::Rendering, AbstractController::Rendering, AbstractController::ViewPaths, ActionController::Redirecting, ActionController::RackDelegation, ActiveSupport::Benchmarkable, AbstractController::Logger, ActionController::UrlFor, AbstractController::UrlFor, ActionDispatch::Routing::UrlFor, ActionDispatch::Routing::PolymorphicRoutes, ActionController::ModelNaming, ActionController::HideActions ]
88. NO CAPTION
89. Y U NO Sinatra!!!
91. Y U NO Sinatra!!! “Any sufficiently advanced sinatra application is indistinguishable from rails”
93. don’t reinvent this
94. ActiveModel Serializers
95. Jbuilder.encode do |json| json.content format_content(@message.content) json.(@message, :created_at, :updated_at) ! json.author do json.name @message.creator.name.familiar json.email_address @message.creator.email_address_with_name json.url url_for(@message.creator, format: :json) end ! if current_user.admin? json.visitors calculate_visitors(@message) end ! json.comments @message.comments, :content, :created_at ! json.attachments @message.attachments do |attachment| json.filename attachment.filename json.url url_for(attachment) end end
97. DHH CHANGES NAME TO BASECAMP
98. Jbuilder json json ! json json json json end ! if json end ! json ! json json json end end
99. % rails g serializer …
100. class PostSerializer < ActiveModel::Serializer attributes :id, :title, :body has_many :comments end
101. class PostSerializer < ActiveModel::Serializer attributes :id, :title, :body, :synopsis has_many :comments ! def comments object.comments.where(:author => scope) end ! def synopsis object.body.truncate(30) end end
102. class PostsController < ApplicationController def show @post = Post.find(params[:id]) respond_with @post end end
103. CONVENTION!
104. VIEWS
105. class PostSerializer < ActiveModel::Serializer attributes :id, :title, :body has_many :comments has_many :tags has_many :images belongs_to :author end WARNING!
106. class attributes has_many has_many has_many belongs_to end CONGRATULATIONS!!! YOU SERIALIZED YOUR DATABASE
107. CONDITIONAL REQUESTS
108. $ curl -i https://api.example.com/user ! HTTP/1.1 200 OK Cache-Control: private, max-age=60 ETag: "644b5b0155e6404a9cc4bd9d8b1ae730" Last-Modified: Thu, 02 Feb 2014 15:31:30 GMT Status: 200 OK
109. $ curl -i https://api.example.com/user -H ‘If-None-Match: ”{Etag}”’ ! HTTP/1.1 304 Not Modified Cache-Control: private, max-age=60 ETag: "644b5b0155e6404a9cc4bd9d8b1ae730" Last-Modified: Thu, 02 Feb 2014 15:31:30 GMT Status: 304 Not Modified
110. class PostsController < ApplicationController def show @post = Post.find(params[:id]) ! if stale? @post respond_with @post end end end
111. class PostsController < ApplicationController def show @post = Post.find(params[:id]) ! if stale? @post respond_with @post end end end etag: Model#cache_key last_modified: Model#updated_at
112. class PostSerializer < ActiveModel::Serializer cached ! delegate :cache_key, :to => :object end
113. ActiveModel Serializers CACHE
114. GATEWAY CACHING
115. TESTABLE?
116. rack-test
119. JSON-API RAILS-API AMS = ❤️
120. JSON-API RAILS-API AMS =
121. THE REST…?
122. THANKS! @benlovell