AWS Lambda Handler Cookbook (Python)

This project provides a working, open source based, AWS Lambda handler skeleton Python code including DEPLOYMENT code with CDK and a pipeline.

This project can serve as a template for new Serverless services - CDK deployment code, pipeline and handler are covered.

📜Documentation | Blogs website

Contact details | ran.isenberg@ranthebuilder.cloud

The Problem

Starting a Serverless service can be overwhelming. You need to figure out many questions and challenges that have nothing to do with your business domain:

• How to deploy to the cloud? What IAC framework do you choose?
• How to write a SaaS-oriented CI/CD pipeline? What does it need to contain?
• How do you handle observability, logging, tracing, metrics?
• How do you handle testing?
• What makes an AWS Lambda handler resilient, traceable, and easy to maintain? How do you write such a code?

The Solution

This project aims to reduce cognitive load and answer these questions for you by providing a skeleton Python Serverless service template that implements best practices for AWS Lambda, Serverless CI/CD, and AWS CDK in one template project.

Serverless Service - The Order service

• This project provides a working orders service where customers can create orders of items.

• The project deploys an API GW with an AWS Lambda integration under the path POST /api/orders/ and stores data in a DynamoDB table.

Features

• Python Serverless service with a recommended file structure.
• CDK infrastructure with infrastructure tests and security tests.
• CI/CD pipelines based on Github actions that deploys to AWS with python linters, static code analysis, complexity checks and style formatters.
• The AWS Lambda handler embodies Serverless best practices and has all the bells and whistles for a proper production ready handler.
• AWS Lambda handler uses AWS Lambda Powertools.
• Unit, integration and E2E tests.

CDK Deployment

The CDK code create an API GW with a path of /api/orders which triggers the lambda on 'POST' requests.

The AWS Lambda handler uses a Lambda layer optimization which takes all the packages under the [packages] section in the Pipfile and downloads them in via a Docker instance.

This allows you to package any custom dependencies you might have, just add them to the Pipfile under the [packages] section.

Serverless Best Practices

The AWS Lambda handler will implement multiple best practice utilities.

Each utility is implemented when a new blog post is published about that utility.

The utilities cover multiple aspect of a production-ready service, including:

• Logging
• Observability: Monitoring and Tracing
• Observability: Business KPIs Metrics
• Environment Variables
• Input Validation
• Dynamic Configuration & feature flags
• Start Your AWS Serverless Service With Two Clicks
• CDK Best practices

Getting started

Head over to the complete project documentation pages at GitHub pages at https://ran-isenberg.github.io/aws-lambda-handler-cookbook

Code Contributions

Code contributions are welcomed. Read this guide.

Code of Conduct

Read our code of conduct here.

Connect

• Email: ran.isenberg@ranthebuilder.cloud
• Blog Website RanTheBuilder
• LinkedIn: ranisenberg
• Twitter: IsenbergRan

Credits

• AWS Lambda Powertools (Python)

License

This library is licensed under the MIT License. See the LICENSE file.