jsec / calculator-api

A demo calculator API built using AWS CDK

Calculator API

This project is a very rudimentary calculator API, deployed on AWS, using the AWS CDK to describe the infrastructure.

High Level Diagram

CDK Constructs Used

• aws-kms.Key: For encrypting environment variables inside a Lambda function
• aws-lambda.NodejsFunction: A specialized version of Lambda.Function that automatically handles transpilation from TypeScript to JavaScript
• aws-apigateway.RequestValidator: A validator to ensure correctness of query parameters
• aws-apigateway.RestApi: The umbrella API Gateway instance that routes requests to the correct handler
• aws-apigateway.LambdaIntegration: A construct to connect an API Gateway resource to a particular Lambda function

API

The API is expressed as 4 GET endpoints, one for each arithmetic operation. Each endpoint requires 2 query parameters, value1 and value2. For the multiplication, division, and subtraction endpoints, value1 will come first in the "equation" (ie. value1 / value2).

• Addition: GET /add?value1=4&value2=5
• Subtraction: GET /subtract?value1=4&value2=5
• Multiplication: GET /multiply?value1=4&value2=5
• Division: GET /divide?value1=4&value2=5

Wishlist Items to Add Given More Bandwidth

• Route53 custom domain creation and associated ACM cert.
• Refactoring of the lambda and endpoint method creation logic. Creating a factory method for each would cut down a lot of boilerplate in the stack definition.