This project consists of a single API Lambda function deployed to AWS that can be accessed using the Function URL(FURL). The AWS CDK has been used to define the IaC and the Lambda is written in TS. It has two endpoints:

• Get all pets
• Get a pet by ID

A pre-build step uses the OpenAPI spec (src/openapi/openapi.yaml) to generate TS types to be used at compile time. It also uses the Open API spec to generate JS validation functions using the AJV standalone method that can be used at runtime. This is how we validate both the input and output of our API and make it the source of truth for our API.

Deployment is done manually using the JS GULP script in this project. This project does it manually to keep it brief, but ideally you do this in your pipeline. After the CDK is deployed (with the cdk_deploy command), it publishes the API SDK as an NPM package to GitHub. The published NPM package version is the same as the OpenAPI spec version and will only be published if the version is more than the current version.

You can use the GULP plugin for your IDE to debug and run the gulpfile.js that is used as the build script. You can also run the scripts vianpm run <TASK> for your convenience.

1. Replace the values if you want to do deploy to AWS and publish the API as an SDK in the gulpfile.js on lines 45-52:

• <YOUR AWS PROFILE NAME TO USE FOR DEPLOYMENTS>
• <AWS REGION TO DEPLOY IN>
• <AWS ACCOUNT ID TO DEPLOY IN>
• <HTTPS URL OF THE EXISTING EMPTY GITHUB REPO TO STORE THE API SDK ENDING IN .git> example https://github.com/rehanvdm/pets-api.git
• <SDK PACKAGE NAME AS IN THE package.json> must start with @, example @rehanvdm/pets-api
• <SDK PACKAGE REPO AS IN THE package.json> example git://github.com/rehanvdm/pets-api.git

Useful commands:

• npm run build_types - Takes the OpenAPI spec and creates TS types to be used at compile time as well as JS validation functions to be used at runtime.
• npm run watch_types - Watches the OpenAPI spec at src/openapi/openapi.yaml and if they change, it runs the build_types command above.
• npm run build_lambdas - Does the TS => JS transpolation and then copies the src files to the dist folder.
• npm run test - Runs the test/api.js file that contains basic Mocha & Chai tests that first transpiles the TS to JS with the same ESBuild function that is used for deployments in the GULP file. Then it passes an event and context to the function to test it locally.

1. Create a Personal Access Token(PAT) on GitHub so that we can write the SDK API NPM package. You need to assign the flowing permissions:
   • write:packages Upload packages to the GitHub Package Registry
2. Make a copy of the .npmrc.example file and replace: -<YOUR PERSONAL ACCESS TOKEN HERE> with your GitHub Personal Access Token (PAT) that you obtained above -<YOUR GITHUB PROFILE OR ORGANIZATION NAME> with your GutHub username of where the package is installed

Deploys a Lambda + FURL on AWS.

• npm run cdk_diff - Runs build_types and build_lambdas, then the cdk diff command.
• npm run cdk_deploy - Runs build_types and build_lambdas, then the cdk deploy command. After that it runs the generate_and_push_api_sdk command to do the API SDK generation and package publishing logic.
• npm run cdk_hotswap - Runs build_types and build_lambdas, then the cdk deploy --hotswap command.

After you deployed, you will be given the Function URL. You will have to update the API URL in the frontend repository with this value.

See the frontend docs here: https://github.com/rehanvdm/pets-frontend