Mosaic - AWS Lambda Template (NodeJS and TypeScript)

This project serves as a template for creating AWS Lambda functions using Node.js and TypeScript.

It aims to provide a foundation for developing serverless applications on AWS platform with Integrations (Ingress and Egress) mentioned below.

Integrations

Ingress (Lambda Handlers)

1. Lambda
2. Kafka
3. API Gateway
4. S3

Egress (Service Clients)

1. Hasura
2. Kafka - MSK
3. Function - AWS Lambda
4. Object Storage - S3
5. Secrets Management - AWS Secrets Manager
6. Microservices - ECS (TBD)
7. Application Config - Launch Darkly (TBD)

Technical Specifications

Runtime - NodeJS

Language - TypeScript

Libraries

1. AWS SDK - Used to Call S3, Lambdas, ECS, Secret Manager
2. Lambda Power Tools - Used for Logging Framework
3. Axios - Used to Call Hasura, External API's
4. Kafka JS - Used to Produce Messages to Kafka
5. Webpack - Used for Transpiling the TypeScript Code, minify and Bundle it
6. Jest - Unit Testing Framework
7. ES Lint - Static Code Analyzer
8. Prettier - Code Formatter
9. Gradle - Dependency Management, Release Versioning
10. Zod - Validation Library
11. Handlebars - Templating Engine
12. Date Fns - Date Manipulation Library

Steps to create a new Lambda Function

1. Run the Github Actions Workflow in https://github.com/VMobilitySandbox/DeveloperTools to create your own repos based on the template
2. Start by updating the necessary configuration (Name, Description) in the package.json and folder structure to reflect the name of the service.
3. Remove the Dependencies from package.json which are not necessary for your application.
4. Rename the Lambda handler file to index.ts (index_Kafka.ts becomes index.ts).
5. Remove any redundant handler files that are not needed for the service.
6. Review the contents of the Client and Config folders, retaining only the clients and configurations essential for the service. Delete any unnecessary files within these folders.
7. Remove any unnecessary Jest Test Files or Integration Test Files not needed for your application.
8. In the InitializationService.ts file, include only the function calls necessary for the initialization phase of your service. Remove any unused function calls.
9. Remove the provided DummyService and DummyModels files, as they are only provided for reference and are not required for the service.
10. Update the default-config.json and env-config.json file with the default configurations required for your service. These configurations can be overridden if necessary using Lambda Environment Variables.
11. Run npm install to download the dependencies.
12. Ensure that SERVICE_NAME and ENVIRONMENT are added to the default-config.json.
13. Create a README.md file based on the template provided in APP_README.md, filling in all necessary details about the service.
14. Create a CHANGELOG.md file based on the template provided in APP_CHANGELOG.md, documenting all changes made in each release of the service. Include details about enhancements, bug fixes, and any other modifications made.

Note

1. This is a template with boilerplate code, Ensure that you integrate the necessary services and thoroughly test it.
2. Avoid implementing any business logic within the handler.
3. The code within the handler of the template is solely for demonstration purposes.
4. Refer to Development Workflow - Best Practices in https://dev.azure.com/atsol/Mosaic/_wiki/wikis/Mosaic.wiki/2107/Development-Workflow-Best-Practices

Pending Items

1. Launch Darkly Integration

Integration Testing

Integration Testing can be done in AWS Workspace using the Test classes provided in integration folder

1. Configure your Integration Test File name correctly in .vscode\launch.json
2. Use the Run and Debug pane in VS Code to run the Integration Test