Q&A for 
 How to use OpenAPI3 for API developer AFTER RubyKaigi 2019 ota42y

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about me • @ota42y • ϔϧεςοΫΧϯύχʔͷαʔόαΠυΤϯδχΞ • ϚΠΫϩαʔϏεΑΖͣຊΈ͍ͨͳͷΛग़ͯ͠·͢ • ిࢠ൛΋͋ΔΑ(ƅ㱼ƅ)oኯƅ • https://ota42y.booth.pm/items/1316740 • https://ota42y.booth.pm/items/1316130

Today’s topic • OpenAPI3ͷൃදͷ͓͞Β͍ • دͤΒΕ࣭ͨ໰ͱճ౴

OpenAPI3ͷൃදͷ͓͞Β͍

OpenAPI3 • ϓϩάϥϛϯάݴޠʹґଘ͠ͳ͍REST APIͷͨΊͷఆٛ • ͔ͭͯ͸Swaggerͱݺ͹Ε͍ͯͯɺͦΕͷ࣍όʔδϣϯ • ϚγʔϯϦʔμϒϧͳYAML/JSONͷϧʔϧͰɺυΩϡϝϯτ ੜ੒΍όϦσʔγϣϯɺϞοΫαʔό΍ϥΠϒϥϦੜ੒ͳͲԠ ༻͸ଟ਺ https://www.openapis.org/

APIͷఆٛͷॏཁੑ • େྔʹAPI͕͋Δ৔߹ɺυΩϡϝϯτ͕ॏཁʹͳΔ
 (ϚΠΫϩαʔϏεͩͱ1000ݸҎ্API͕͋ͬͨΓ͢Δ) • εΩʔϚϑΝʔετ։ൃ͢Δ৔߹ɺΠϯλϑΣʔεΛ͖ͬͪΓ ఆٛ͢Δඞཁ͕͋Δ • εΩʔϚϑΝʔετ։ൃʹ͍ͭͯৄ͘͠͸ͬͪ͜ Reference: RubyKaigi 2017 API Development in 2017 https://www.youtube.com/watch?v=a28jJ62ZfZM Rails Developers Meetup 2019: 
 https://speakerdeck.com/aeroastro/rails-meets-protocol-buffers-for-schema-first-development

ਓͷखʹΑΔԹ͔Έͷ͋Δఆٛ͸่ΕΔ • ࣮૷ͱఆ͕ٛҰக͍ͯ͠Δͷ͕େલఏ • ͣΕΔͱఆ͕ٛ৴པͰ͖ͳ͘ͳΔ • ౒ྗͰҰகͤ͞Δͷ͸ແཧ

OpenAPI 3ʹΑΔࣗಈνΣοΫ • OpenAPI 3͸ϚγʔϯϦʔμϒϧͳఆٛ • ఆٛͱͷζϨΛϓϩάϥϜͰνΣοΫͰ͖Δ • committee • rack૚Ͱrequest/response͕ఆٛͲ͓Γ͔ΛνΣοΫ͢Δgem • ఆٛ௨Γͷ࣮૷Ͱ͋ΔͱอূͰ͖Δ

Example API get "/apps" do content_type :json # page should be Integer page = params["page"] [page, (page*10)].map(&:to_s).to_json end

Example API openapi: 3.0.0 info: title: Sample API version: 0.1.0 paths: "/apps": get: parameters: - name: page in: query required: true schema: type: integer responses: '200': description: example content: 'application/json': schema: type: array items: type: string

Example API openapi: 3.0.0 info: title: Sample API version: 0.1.0 paths: "/apps": get: parameters: - name: page in: query required: true schema: type: integer responses: '200': description: example content: 'application/json': schema: type: array items: type: string

Example API openapi: 3.0.0 info: title: Sample API version: 0.1.0 paths: "/apps": get: parameters: - name: page in: query required: true schema: type: integer responses: '200': description: example content: 'application/json': schema: type: array items: type: string

ͦͷଞͷOpenAPI 3ͷ׆༻ • OpenAPI Generator • client libraryΛੜ੒͢Δπʔϧ • Swagger Editor • OpenAPI 3ͷఆٛΛॻ͘ΠϯλϥΫςΟϒͳΤσΟλ • ࣮ࡍʹαʔόʹϦΫΤετΛ஗ΕΔυΩϡϝϯτΛॻ͚Δ • ଞʹ΋Protocol BuffersΛੜ੒ͨ͠Γͱ͔৭ʑ…ৄ͘͠͸ https://openapi.tools/ ΁

Q&A for 
 How to use OpenAPI 3 for API developer

Q.committee͸ຊ൪؀ڥͰ࢖ͬͯΔ͔? • Yes • committee͸ܕͷύϥϝʔλΛม׵͢Δػೳ͕͋ΔͷͰrequestͰ͸࢖ͬͯΔ
 (datetimeͳstringΛDateTimeΫϥεʹͨ͠ΓɺGETͩͱ͢΂ͯstringʹͳΔͷ ͰIntegerʹ͢Δͱ͔) • ϦΫΤετʹ͔͠దԠ͞Εͳ͍ͨΊɺϨεϙϯεͷόϦσʔγϣϯ͸ͯ͠ͳ͍ • ։ൃ؀ڥʹ͓͍ͯ͸requset/responseͷόϦσʔγϣϯΛೖΕ͍ͯΔ

Q.committee ΛೖΕͨ͜ͱʹΑΔӨڹ͸? • ϕϯνϚʔΫΛऔΓ·ͨ͠ • https://gist.github.com/ota42y/1a5fb27e31aa5868af307fd66f52878b • ύϥϝʔλ͕1ݸͷখن໛ • ύϥϝʔλ͕260ݸͷதن໛ • ύϥϝʔλ͕2600ݸͷେن໛ • ͦΕͧΕcommitteeͷON/OFFͰ10000ճܭଌ

committee ΛೖΕͨ͜ͱʹΑΔӨڹ͸? • responseʹؔͯ͠͸νΣοΫͯ͠ͳ͍ • ࣮૷ͱͯ͠͸ڞ௨ͳͷͰ΄΅มΘΒͳ͍͸ͣ • ؀ڥ͸Ruby 2.6.3ɺMac Book Pro, Core i5 2.7GHz

ίʔυ • https://gist.github.com/ota42y/ 1a5fb27e31aa5868af307fd66f52878b

VTFS TZTUFN UPUBM SFBM /PU6TF 6TF খن໛ • 10000 times request time so 0.08 ms per request • So the committee doesn’t take 0.1 millisecond • The difference is very small

தن໛ • Validate 260 objects by 0.16 milliseconds per request • But the difference is still small VTFS TZTUFN UPUBM SFBM /PU6TF 6TF

େن໛ • Validate 2600 objects by 0.74 milliseconds per request • It’s very small difference VTFS TZTUFN UPUBM SFBM /PU6TF 6TF

A.ϕϯνϚʔΫ݁Ռ • தن໛ύϥϝʔλͰ΋େ͖ࠩ͘͸ग़ͯͳ͍ • Mac Book Pro؀ڥͰ0.1ʙ2ms • Կ΋ແ͍࣌ͱͷࠩ͸খ͍͞ • ࣮ࡍͷαʔόͰ΋΄΅Өڹ͸ແ͍͸ͣ • requestʹ100ύϥϝʔλ৐Δͷ͸͔ͳΓେ͖͍͜ͱΛߟ͑Δͱɺ΄΅ແࢹ Ͱ͖Δ͸ͣ

Q. OpenAPI 3.0.1ͩͱಈ͔ͳ͍Μ͚ͩͲ • ͖ͬ͞௚͠·ͨ͠

Q. OpenAPI 3.0.1ͩͱಈ͔ͳ͍Μ͚ͩͲ • ϦϦʔε΋ͯ͋͠Γ·͢㱬(ɾ8ɾ)⊃

ຊ൪͸͜͜Ͱ࣌ؒ੾Ε

Q.GraphQL / gRPC ͱൺ΂ͯͲ͏Α • ͲΕ͕͍͍͔͸ϝϯόʔ΍ΫϥΠΞϯτଆͷ࣮૷ɺݴޠʹΑΔ • GraphQL͸ಋೖ͚ͯͨ͠ͲΞϓϦଆͷ࣮૷ઓུʹ߹Θͣʹ׆༻Ͱ͖ͣɺ݁ ہࣺͯͨ • gRPC͸Railsͩͱݱঢ়·ͩਏ͍ͱ͍͏ࣄ࣮ • Go ͱ͔ͳΒ༗ྗͳબ୒ࢶ • ΫοΫύου͕ؤுͬͯΔ

ࠓͷੈք͸RESTʹ࠷దԽ͞ΕͯΔ • ΤίγεςϜͱ͔஌ݟ͸REST͕ੌ͍ • ͦ΋ͦ΋Rails͸RESTͱ਌࿨ੑ͕͍͍ • GraphQL/gRPCΛೖΕΔͷ͸͍ͩͿΤωϧΪʔ͕ඞཁ • ಉ͡࿑ྗΛRESTͱGraphQL/gRPCͷͲΕʹׂ͘ͷ͕Ұ൪͔ • ͔ͳΓޮՌతͳ৔໘΋͋ΔͷͰɺݟۃΊͱ֮ޛ