swift-sls-adapter

Swift serverless.yml adapter. Read and Write a Serverless Framework configuration in Swift.

The Serverless framework is an All-in-one development solution for auto-scaling apps on AWS Lambda. The serverless.yml file represents the deployment configuration. This swift package allows Encoding and Decoding a serverless.yml using Yams.

Installation

Swift Package Manager

Add the following packages to your swift package

dependencies: [
    // ...
    .package(url: "https://github.com/swift-sprinter/swift-sls-adapter.git", from: "0.1.0")
]

Usage

Decode:

import Foundation
import SwiftSlsAdapter
import Yams

let fileUrl =  URL(fileURLWithPath: "servreless.yml")
let serverlessYml: Data = Data(contentsOf: fileUrl)
let decoder = YAMLDecoder()
let serverlessConfig = try decoder.decode(ServerlessConfig.self, from: serverlessYml)

Encode:

import Foundation
import SwiftSlsAdapter
import Yams

// Initialise ServerlessConfig
let iam = Iam(
    role: Role(
        statements: [
            Statement(
                effect: "Allow",
                action: [
                    "logs:CreateLogGroup",
                    "logs:CreateLogStream",
                    "logs:PutLogEvents"
                ],
                resource: try YAMLContent(with: "*")
            ),
            Statement(
                effect: "Allow",
                action: [
                    "dynamodb:UpdateItem",
                    "dynamodb:PutItem",
                    "dynamodb:GetItem",
                    "dynamodb:DeleteItem",
                    "dynamodb:Query",
                    "dynamodb:Scan",
                    "dynamodb:DescribeTable"
                ],
                resource: try YAMLContent(with: [["Fn::GetAtt": ["ProductsTable", "Arn"]]])
            )
        ]))
let environment = try YAMLContent(with: ["PRODUCTS_TABLE_NAME": "${self:custom.tableName}"])
let provider = Provider(
    name: .aws,
    region: .eu_west_1,
    runtime: .providedAl2,
    environment: environment,
    lambdaHashingVersion: "20201221",
    architecture: .arm64,
    httpAPI: .init(payload: "2.0", cors: true),
    iam: iam
)
let custom = try YAMLContent(with: ["tableName": "products-table-${sls:stage}"])
let layer = Layer(
    path: "./build/swift-lambda-runtime",
    name: "aws-swift-sprinter-lambda-runtime",
    description: "AWS Lambda Custom Runtime for Swift-Sprinter"
)

let package = Package(
    patterns: [
        "!**/*",
        "build/Products"
    ],
    individually: true
)

let layersRef = try YAMLContent(with: [["Ref": "SwiftDashlambdaDashruntimeLambdaLayer"]])

let path = "/products"
let keyedPath = "/products/{sku}"

let createProduct = Function(
    handler: "build/Products.create",
    runtime: nil,
    memorySize: 256,
    description: "[${sls:stage}] Create Product",
    package: package,
    layers: layersRef,
    events: [.init(httpAPI: .init(path: path, method: .post))]
)

let readProduct = Function(
    handler: "build/Products.read",
    runtime: nil,
    memorySize: 256,
    description: "[${sls:stage}] Get Product",
    package: package,
    layers: layersRef,
    events: [.init(httpAPI: .init(path: keyedPath, method: .get))]
)

let updateProduct = Function(
    handler: "build/Products.update",
    runtime: nil,
    memorySize: 256,
    description: "[${sls:stage}] Update Product",
    package: package,
    layers: layersRef,
    events: [.init(httpAPI: .init(path: path, method: .put))]
)

let deleteProduct = Function(
    handler: "build/Products.delete",
    runtime: nil,
    memorySize: 256,
    description: "[${sls:stage}] Delete Product",
    package: package,
    layers: layersRef,
    events: [.init(httpAPI: .init(path: keyedPath, method: .delete))]
)

let listProducts = Function(
    handler: "build/Products.list",
    runtime: nil,
    memorySize: 256,
    description: "[${sls:stage}] List Products",
    package: package,
    layers: layersRef,
    events: [.init(httpAPI: .init(path: path, method: .get))]
)

let resource = Resource.dynamoDBResource(tableName: "${self:custom.tableName}", key: "sku")
let resources = Resources.resources(with: ["ProductsTable": resource])

let serverlessConfig = ServerlessConfig(
    service: "swift-sprinter-rest-api",
    provider: provider,
    package: .init(patterns: nil, individually: true, artifact: nil),
    custom: custom,
    layers: ["swift-lambda-runtime": layer],
    functions: [
        "createProduct": createProduct,
        "readProduct": readProduct,
        "updateProduct": updateProduct,
        "deleteProduct": deleteProduct,
        "listProducts": listProducts
    ],
    resources: try YAMLContent(with: resources)
)

let encoder = YAMLEncoder()
let content = try encoder.encode(serverlessConfig)

Supported Serverless Features

The package is under development.

Status of the features implemented in this package:

Feature	Support
Root Properties	✅
Parameters	✅
Provider	aws
General Settings	✅
General Function Settings	✅
Deployment Bucket	❌
API Gateway v2 HTTP API	✅
API Gateway v1 REST API	❌
ALB	❌
Docker image deployments in ECR	❌
IAM permissions	✅
VPC	❌
S3 buckets	❌
Package	✅
Functions	✅
Lambda events	✅
API Gateway v2 HTTP API	✅
API Gateway v1 REST API	❌
API Gateway v1 REST API	❌
Websocket API	❌
S3 events	❌
S3 Schedule	❌
SNS	❌
SQS	❌
Streams	❌
MSK	❌
ActiveMQ	❌
Kafka	❌
Kafka	❌
RabbitMQ	❌
Alexa	❌
IOT	❌
CloudWatch	❌
Cognito	❌
ALB	❌
EventBridge	❌
CloudFront	❌
Function layers	✅
AWS Resources	✅

Contributions

Contributions are more than welcome! Follow this guide to contribute.

References

https://www.serverless.com/framework/docs/providers/aws/guide/serverless.yml