Building a Swift Web API and Application Together

Transcript

1. Building a Swift Web API and Application Together Kyle Fuller
2. Agenda —API Design —Building API in Swift —Deploying API in Swift in production
3. API Design
4. What makes a good API?
5. What makes a good API? —Decoupled from implementation details —Able to evolve without breaking existing clients
6. Example: Pagination
7. GET /posts
8. GET /posts{?page}
9. GET /posts?page=2
12. ! How can we solve?
13. GET /posts{?before}
14. GET /posts?before=44
15. How do we introduce changes to our API?
16. Versioning APIs
17. /v1/posts{?page} /v2/posts{?before}
18. /posts{?page} /posts{?before}
19. API is coupled to implementation details
20. API is coupled to implementation details
21. What happens when you version an API?
22. What happens when you version an API?
23. How can we design the API without exposing implementation details?
24. REST Representational State Transfer
25. Anticipating change is one of the central themes of REST
26. Evolvability
27. Tight Coupling
28. "You can’t have evolvability if clients have their controls baked into their design at deployment"
29. "Controls have to be learned on the fly. That’s what hypermedia enables"
30. Hypermedia
31. Web Linking RFC 5988
32. GET /posts Link: </posts?before=30>; rel="next", </posts?before=120>; rel="last"
33. GET /posts?before=120 Link: </posts?before=90>; rel="prev", </posts>; rel="first"
34. WebLinking.swift https://github.com/kylef/WebLinking.swift
35. WebLinking: Checking for next link if let link = response.findLink(relation: "next") { print("We have a next link with the URI: \(link.uri).") }
36. WebLinking: Introspecting Available Links for link in response.links { print("Relation: \(link.relationType)") print("URI: \(link.uri)") }
37. application/hal+json
38. Blog Post { "title": "My First Blog Post", "body": "Lorem Ipsum" }
39. Blog Post (Next Link) { "title": "My First Blog Post", "body": "Lorem Ipsum", "_links": [ { "href": "/posts/2", "relation": "next" } ] }
40. Blog Post (Self) { "title": "My First Blog Post", "body": "Lorem Ipsum", "_links": [ { "href": "/posts/1", "relation": "self" }, { "href": "/posts/2", "relation": "next" } ] }
41. Blog Post (Comments) { "title": "My First Blog Post", "body": "Lorem Ipsum", "_links": [ { "href": "/posts/1", "relation": "self" }, { "href": "/posts/2", "relation": "next" }, { "href": "/posts/1/comments", "relation": "comments" }, ] }
42. Blog Post (Embedded Comments) { "_embed": { "comments": [ { "author": "Kyle", "body": "That's a really interesting post!" "_links": [ { "href": "/posts/1/comments/1", "relation": "self" } ] } ] } }
43. application/ vnd.siren+json
44. Delete Post { "properties": { "title": "My First Blog Post", "body": "Lorem Ipsum", }, "actions": [ { "name": "delete", "method": "DELETE", "href": "/posts/1" } ] }
45. Delete Post { "properties": { "title": "My First Blog Post", "body": "Lorem Ipsum", }, "actions": [ { "name": "delete", "method": "DELETE", "href": "/posts/1" } ] }
46. Create Comment { "properties": { "title": "My First Blog Post", "body": "Lorem Ipsum", }, "actions": [ { "name": "comment", "method": "POST", "href": "/posts/1/comments", "fields": [ { "name": "author", "type": "string" }, { "name": "message", "type": "string" } ] } ] }
47. Create Comment (Logged in) { "properties": { "title": "My First Blog Post", "body": "Lorem Ipsum", }, "actions": [ { "name": "comment", "method": "POST", "href": "/posts/1/comments", "fields": [ { "name": "message", "type": "string" } ] } ] }
48. Hypermedia —Remove implementation details from interface —Keep business logic on back-end, not front-end
49. Building an API in Swift
50. Web Frameworks
51. Web Frameworks —Frank —IBM Kitura —Vapor
52. Frank vs Kitura vs Vapor
53. Frank get("users", *) { (request, username: String) in return "Hello \(username)" }
54. Server APIs Working Group
55. Server APIs Working Group
56. Useful Tools —Templating Languages —Stencil —Data Persistence —Redis (Redbird) —PostgreSQL
57. Testing
58. XCTest class PersonTests: XCTestCase { let person = Person(name: "Kyle") func testPersonName() { XCTAssertEqual(person.name, "Kyle") } func testPersonDescription() { XCTAssertEqual(person.description, "Kyle") } }
59. extension PersonTests: XCTestCaseProvider { var allTests : [(String, () throws -> Void)] { return [ ("testPersonName", testPersonName), ("testPersonDescription", testPersonDescription), ] } } XCTMain([ PersonTests(), ])
60. Dredd https://github.com/apiaryio/dredd
61. API Blueprint # GET /hello + Response 200 (application/json) { "name": "Kyle" }
62. Dredd Testing $ dredd \ apidescription.apib \ https://localhost:8080 ✔ GET /hello ✔ API Matches API Description
63. Deployment
64. https://github.com/kylef/heroku-buildpack-swift
65. $ cat Package.swift import PackageDescription let package = Package( name: "Hello", dependencies: [ .Package(url: "https://github.com/nestproject/Frank.git", majorVersion: 0, minor: 3), ] )
66. $ cat Sources/main.swift import Frank get { _ in return "Hello World" } get(*) { (_, username: String) in return "Hello \(username)" }
67. $ cat Sources/main.swift import Frank get { _ in return "Hello World" } get(*) { (_, username: String) in return "Hello \(username)" }
68. $ cat .swift-version 3.0.2
69. $ cat .swift-version 3.0.2
70. $ swift build $ .build/debug/Hello [INFO] Listening at http://0.0.0.0:8000 (48827) [INFO] Booting worker process with pid: 48828
71. $ cat Procfile web: Hello
72. $ heroku create --buildpack https://github.com/kylef/heroku-buildpack-swift.git $ git push heroku master remote: -----> Swift app detected remote: -----> Installing 3.0.2 remote: -----> Installing clang-3.7.0 remote: -----> Building Package remote: -----> Copying binaries to 'bin'
76. Manual Deployment
77. Monitoring
78. Logging
79. print("ERROR: Connection to database failed \(error)")
80. Papertrail
83. Conclusion —API Design —Swift Web Services —Tools & Frameworks —Testing —Deployment —Monitoring
84. Conclusion —API Design —Swift Web Services —Tools & Frameworks —Testing —Deployment —Monitoring
85. kylefuller https://fuller.li/talks