swift-serverless/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.

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()

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.

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

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

• 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://.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

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

./build.sh

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.

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

./update.sh

To remove the deployment:

./remove.sh

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

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

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:          .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.