The document outlines a presentation by Andrea Scuderi on using serverless architecture in Swift, including a demonstration of a full-stack Swift application. Key topics covered include app architecture, code structure, deployment processes, and the advantages of serverless computing. It also highlights the ease of integration and scalability offered by serverless solutions using AWS services, along with practical implementation steps for developers.

1. SERVERLESS IN SWIFT LIKE A BREEZE
ANDREA SCUDERI
SENIOR IOS ENGINEER @ JUST EAT TAKEAWAY
NSLondon
2023.2

2. AGENDA
▸ Demo App with Serverless
▸ App & Serverless Architecture
▸ Code Structure
▸ Code Generation
▸ Deployment
▸ Why Serverless, Why Swift? Why Breeze?

3. FULL STACK SWIFT

4. DEMO APP
GITHUB.COM/SWIFT-SPRINTER/BREEZEDEMOAPP
▸ SwiftUI
▸ Apple Sign In
▸ Serverless API in Swift
▸ CRUD (Create, Read, Update, Delete)

5. DEMO APP
DATA MODEL
public struct Form: Codable {
public var key: String
public let name: String
public let fields: [Field]
public var createdAt: String?
public var updatedAt: String?
public init(key: String,
name: String,
fields: [Field],
createdAt: String? = nil,
updatedAt: String? = nil) {
self.key = key
self.name = name
self.fields = fields
self.createdAt = createdAt
self.updatedAt = updatedAt
}
enum CodingKeys: String, CodingKey {
case key = "formKey"
case name
case fields
case createdAt
case updatedAt
}
}
public struct Field: Codable {
public let question: String
public let answer: String?
public let choices: [String]?
public let selected: [String]?
public let type: FieldType
public init(question: String,
answer: String? = nil,
choices: [String]? = nil,
selected: [String]? = nil,
type: FieldType) {
self.question = question
self.answer = answer
self.choices = choices
self.selected = selected
self.type = type
}
}
public enum FieldType: String, Codable {
case text
case option
case multiOption
}

6. SERVERLESS NO-SQL DB
AWS DYNAMODB
{
"formKey": {
"S": "114800A1-162F-4877-81BC-96E9A42E6559"
},
"createdAt": {
"S": "2023-05-06T08:31:37.866Z"
},
"fields": {
"L": [
{
"M": {
"choices": {
"L": [
{
"S": "Cost savings 💰 "
},
{
"S": "Performance ⚡ "
},
{
"S": "Scalability 🚀 "
},
{
"S": "Infrastructure as a Code 💨 "
}
]
},
"question": {
"S": "What is the main benefit of Serverless computing?"
},
"selected": {
"L": [
{
"S": "Cost savings 💰 "
},
{
"S": "Performance ⚡ "
},
{
"S": "Infrastructure as a Code 💨 "
},
{
"S": "Scalability 🚀 "
}
]
},
"type": {
"S": "multiOption"
}
}
},
{
"M": {

7. MOBILE & SERVERLESS
ARCHITECTURE
Mobile App API Gateway
HTTP/REST
+ (Bearer Token)
OAUTH 2.0
PROVIDER
JWT Token
https://docs.aws.amazon.com/apigateway/latest/developerguide/http-api-jwt-authorizer.html
Validation

8. SERVERLESS ARCHITECTURE

9. MOBILE & SERVERLESS
CODE ARCHITECTURE
BreezeLambdaAPIClient SharedModel
public struct Form: Codable {
public var key: String
public let name: String
public let fields: [Field]
public var createdAt: String?
public var updatedAt: String?
public init(key: String,
name: String,
fields: [Field],
createdAt: String? = nil,
updatedAt: String? = nil) {
self.key = key
self.name = name
self.fields = fields
self.createdAt = createdAt
self.updatedAt = updatedAt
}
enum CodingKeys: String, CodingKey {
case key = "formKey"
case name
case fields
case createdAt
case updatedAt
}
}
iOS - Swift
…
BreezeLambdaAPI BreezeDynamoDBService
SOTO

10. SHOW ME THE CODE!

11. APP API SERVICE
SERVICE-BASED BREEZE LAMBDA API CLIENT
struct FormService: FormServing {
private let apiClient: BreezeLambdaAPIClient<FeedbackForm>
private let session: SessionService
private var token: String? {
session.userSession?.jwtToken
}
init(session: SessionService) {
guard var env = try? APIEnvironment.dev() else {
fatalError("Invalid Environment")
}
env.logger = Logger()
self.session = session
self.apiClient = BreezeLambdaAPIClient<FeedbackForm>(env: env, path: "forms", additionalHeaders: [:])
}
func create(form: FeedbackForm) async throws -> FeedbackForm {
try await apiClient.create(token: token, item: form)
}
func read(key: String) async throws -> FeedbackForm {
try await apiClient.read(token: token, key: key)
}
func update(form: FeedbackForm) async throws -> FeedbackForm {
try await apiClient.update(token: token, item: form)
}
Data Model
Environment API PATH
JWT Token

12. APP API SERVICE
BREEZE LAMBDA API CLIENT
struct Environment {
static func dev() throws -> APIClientEnv {
try APIClientEnv(session: URLSession.shared, baseURL: "<API GATEWAY BASE URL FROM SERVERLESS DEPLOY>")
}
}
extension FeedbackForm: KeyedCodable {}
struct Logger: APIClientLogging {
func log(request: URLRequest) {
print(request)
}
func log(data: Data, for response: URLResponse) {
print(response)
let value = String(data: data, encoding: .utf8) ?? ""
print(value)
}
}

13. LAMBDA CODE
ONE LINE OF CODE !!!
import Foundation
import BreezeLambdaAPI
import BreezeDynamoDBService
import SharedModel
extension Form: BreezeCodable { }
BreezeLambdaAPI<Form>.main()
public protocol BreezeCodable: Codable {
var key: String { get set }
var createdAt: String? { get set }
var updatedAt: String? { get set }
}

14. SWIFT !!!
YES, I CAN UNDERSTAND IT!

15. INFRASTRUCTURE AS A CODE
SERVERLESS.YML
▸ API Gateway v2
▸ Lambda
▸ DynamoDB
▸ IAM
▸ Package

16. SERVERLESS.YML ?!?
LOOKS QUITE HARD !

17. HOW DO I START?

18. ▸ A SMALLER YML CONFIG
▸ COMMAND LINE TOOL GENERATES:
▸ PROJECT FOLDER
▸ SWIFT PACKAGE
▸ SERVERLESS.YML
▸ BUILD SCRIPT
▸ DEPLOYMENT SCRIPT
SERVERLESS WITH BREEZE
CODE GENERATION WITH BREEZE
service: swift-breeze-rest-form-api
awsRegion: us-east-1
swiftVersion: 5.7.3
swiftConfiguration: release
packageName: BreezeFormAPI
buildPath: build
cors: false
authorizer: #optional
name: appleJWT
type: JWTAuthorizer
issuerUrl: https://appleid.apple.com
audience:
- com.andrea.DemoApp #APP BUNDLE ID
breezeLambdaAPI:
targetName: FormAPI
itemCodable: Form
itemKey: formKey
httpAPIPath: /forms
dynamoDBTableNamePrefix: forms

19. CODE GENERATION
BREEZE COMMAND LINE
swift run breeze -c breeze.yml -t .build/temp

20. CODE GENERATION
BREEZE COMMAND LINE

21. CODE BUILD
BREEZE BUILD
./build.sh
❌
build
Docker image: swift:5.7-amazonlinux2

22. CODE BUILD
BREEZE BUILD
./build.sh

23. SERVERLESS DEPLOY
BREEZE DEPLOY
./deploy.sh
serverless.yml
build Deployment con
fi
guration
CloudFormation AWS Deployment
serverless deploy

24. SERVERLESS DEPLOY
BREEZE DEPLOY
./deploy.sh

25. SERVERLESS LIKE A BREEZE!

26. BREEZE WORKFLOW
STEP BY STEP WORKFLOW
▸ Git Clone https://github.com/swift-sprinter/Breeze
▸ Copy Breeze.yml con
fi
g from the README
▸ Add the Authorizer to the con
fi
g if you want to secure the API!!!
▸ Adjust the con
fi
guration
▸ Generate the code and customise the data model
▸ Build the Lambdas
▸ Deploy the Serverless
▸ Implement your app using the BreezeLambdaAPIClient

27. WHY SERVERLESS?
WHY SWIFT?
WHY BREEZE?

28. WHY SERVERLESS? WHY SWIFT? WHY BREEZE?
▸ Scalability
▸ Reduced Operational Overhead
▸ Pay per use
▸ Faster Time to market
▸ Easy Integration
WHY SERVERLESS?

29. WHY SERVERLESS? WHY SWIFT? WHY BREEZE?
▸ iOS Developers ❤ it!
▸ No need to learn a new language
▸ Modern and performant language
▸ Safe
▸ Expressive
▸ Fast
WHY SWIFT?

30. ▸ Quick Start!
▸ Project setup
▸ Build
▸ Deploy
▸ Full control
▸ Adaptable
▸ Open Source
WHY SERVERLESS? WHY SWIFT? WHY BREEZE?
WHY BREEZE?

31. GITHUB BREEZE
GITHUB.COM/SWIFT-SPRINTER/BREEZE

32. THANK YOU!

33. ANDREA SCUDERI - SENIOR IOS ENGINEER @ JUST EAT TAKEAWAY
STAY IN TOUCH!
▸ Twitter: @andreascuderi13
▸ Linkedin: https://www.linkedin.com/in/andreascuderi/
▸ Medium: https://medium.com/@andreascuderi73