AWS Serverless Swift API Template

This package demonstrates how to write a Scalable REST API with the Serverless stack by using only Swift as a development language.

Product API based on Breeze

The example shows how to build and deploy a Rest API based on a Product swift struct using Breeze

The following code is all you need to implement the engine of a Serverless Rest API in Swift. The Serverless Rest API implements a CRUD interface to store the Product in DynamoDB.

import Foundation
import BreezeLambdaAPI
import BreezeDynamoDBService

struct Product: Codable {
    public var key: String
    public let name: String
    public let description: String
    public var createdAt: String?
    public var updatedAt: String?
    
    enum CodingKeys: String, CodingKey {
        case key = "sku"
        case name
        case description
        case createdAt
        case updatedAt
    }
}

extension Product: BreezeCodable { }

BreezeLambdaAPI<Product>.main()

API Definition

The API implements the following schema:

- /Product
    -> GET - List Products
    -> POST - Create Products
    -> PUT - Update Products
- /Product/{sku}
    -> DELETE - Delete Product
    -> GET - Get Product

More details of the API are described in swagger.json.

The file can be imported into popular tools such as PostMan.

Be sure to update the "host": "<BASE_URL>" with the URL provided during the deployment.

Serverless architecture

The architecture is based on the classical AWS Serverless stack: APIGateway, Lambda and DynamoDB.

• APIGateway acts as a proxy for Lambda and exposes it to the internet.
• Lambda is the computational layer.
• DynamoDB is the AWS NoSQL database

Advantages:

• Pay per use
• No fixed costs
• Auto-Scaling
• DevOps

REST API Application

The application uses swift-aws-lambda-runtime as AWS Custom Lambda Runtime and acts as a presentation layer of the DynamoDB content providing a REST API.

The following frameworks are used:

• swift-aws-lambda-runtime: Implements the AWS Custom Runtime using Swift NIO.
• aws-sdk-swift: Interacts with DynamoDB

Requirements

• Install Docker
• Install Serverless Framework version 3

Framework Core: 3.25.0 (standalone)
Plugin: 6.2.2
SDK: 4.3.2

• Ensure your AWS Account has the right credentials to deploy a Serverless stack.
• Clone this repository. From the command line type:

git clone https://github.com/swift-serverless/aws-serverless-swift-api-template.git
cd aws-serverless-swift-api-template

• Ensure you can run make:

make --version

the Makefile was developed with this version:

GNU Make 3.81
Copyright (C) 2006  Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.

This program built for i386-apple-darwin11.3.0

Build

Use the following command to build the code before using the serverless commands:

./build.sh

Deploy

Deploy the full solution to your AWS using Serverless:

./deploy.sh

After the deployment is completed, the URL of the website is provided by the Serverless framework.

Update

Rebuild the code and update the Lambda to your AWS using Serverless:

./update.sh

Remove

To remove the deployment:

./remove.sh

arm64 M1 Graviton Support

If the project is built with an M1 processor, then the AWS Lambda will be deployed on the arm64 architecture.

amd64/x86_64 Support

If the project is built with an Intel processor, then the AWS Lambda will be deployed on the x86_64 architecture.

Troubleshooting

• The Serverless version (2.40.0) does not satisfy the "frameworkVersion" (3) in serverless.yml

If during the deployment, the console prints the following message:

Serverless Error ----------------------------------------
 
  The Serverless version (2.40.0) does not satisfy the "frameworkVersion" (3) in serverless.yml
 
  Get Support --------------------------------------------
     Docs:          docs.serverless.com
     Bugs:          github.com/serverless/serverless/issues
     Issues:        forum.serverless.com
 
  Your Environment Information ---------------------------
     Operating System:          darwin
     Node Version:              14.4.0
     Framework Version:         2.40.0 (standalone)
     Plugin Version:            4.5.3
     SDK Version:               4.2.2
     Components Version:        3.9.2

Check the version of Serverless Framework installed in your environment:

sls -v

Framework Core: 2.40.0 (standalone)
Plugin: 4.5.3
SDK: 4.2.2
Components: 3.9.2

It's recommended to upgrade to version 3 the Serverless Framework. In case you want to use version 2 make sure to override the content of serverless.yml with the content of serverless-v2.yml.