App

The application is a CRUD API with Lambda handlers implemented using Java. Its architecture is in the picture given below.

Prerequisites

• Java 11 (Amazon Corretto)
• Apache Maven
• AWS SAM CLI

Development

The Lambda Handlers implement the Amazon API Gateway payload format version 2.0. It is a requirement for invocation of the functions by URL as described in AWS Lambda Developer guide.

Building the application

sam build

Testing it locally

sam local invoke

Adding more SDK clients

To add more service clients, you need to add the specific services modules in pom.xml and create the clients in DependencyFactory following the same pattern as dynamoDbClient.

Deployment

The project contains a SAM template file template.yaml where you can configure different properties of lambda functions such as memory size and timeout. You might also need to add specific policies to the lambda function so that it can access other AWS resources.

To deploy the application, you can run the following command:

sam deploy --guided

See Deploying Serverless Applications for more info.