Using Serverless application to compute the characteristics of geometric shapes

This project contains source code and supporting files for a serverless application that you can deploy with the SAM CLI. It includes the following files and folders.

• Geometry/src/main - Code for the application's Lambda function.
• events - Invocation events that you can use to invoke the function.
• Geometry/src/test - Unit tests for the application code.
• template.yaml - A template that defines the application's AWS resources.

The application uses several AWS resources, including Lambda functions and an API Gateway API. These resources are defined in the template.yaml file in this project.

Deploy the sample application

To deploy using the SAM CLI, you need the following tools.

• SAM CLI
• Java11
• Maven
• Docker

To build and deploy your application for the first time, run the following in your shell:

sam build
sam deploy --guided

You can find your API Gateway Endpoint URL in the output values displayed after deployment.

Use the SAM CLI to build and test locally

Build your application with the sam build command.

$ sam build

The SAM CLI installs dependencies defined in geometry/pom.xml, creates a deployment package, and saves it in the .aws-sam/build folder.

Test a single function by invoking it directly with a test event. An event is a JSON document that represents the input that the function receives from the event source. Test events are included in the events folder in this project.

Run functions locally and invoke them with the sam local invoke command.

$ sam local invoke ShapesFunction --event events/circle-event.json
$ sam local invoke ShapesFunction --event events/square-event.json

The SAM CLI can also emulate your application's API. Use the sam local start-api to run the API locally on port 3000.

$ sam local start-api
$ curl http://localhost:3000/shapes/square?side=10&side=10
$ curl http://localhost:3000/shapes/circle?side=10

The SAM CLI reads the application template to determine the API's routes and the functions that they invoke. The Events property on each function's definition includes the route and method for each path.

      Events:
        Shapes:
          Type: Api
          Properties:
            Path: /shapes/{shapeName}
            Method: get

Fetch, tail, and filter Lambda function logs

$ sam logs -n ShapesFunction --stack-name Shapes --tail

Unit tests

Tests are defined in the geometry/src/test folder in this project.

$ cd geometry
geometry$ mvn test

Cleanup

aws cloudformation delete-stack --stack-name shapes