2.2.1.4. Composing & Deploying IaC Templates (AWS SAM, AWS CloudFormation, AWS CDK)
First Principle: Defining, provisioning, and managing AWS infrastructure repeatably, version-controlled, and automatically ensures consistency, reduces manual errors, and enables rapid, reliable deployments.
Composing and deploying Infrastructure as Code (IaC) templates embodies the principle of automation.
- AWS CloudFormation: (A declarative service for modeling and provisioning AWS resources.) Defines AWS resources using declarative YAML/JSON templates, deploying as "stacks" for complex dependencies and entire application environments.
- AWS Cloud Development Kit (CDK): (An open-source framework to define cloud resources using familiar programming languages (TypeScript, Python, Java, etc.).) A programmatic approach using familiar languages, synthesizing definitions into CloudFormation, offering programmatic control for complex, reusable infrastructure.
- AWS Serverless Application Model (SAM): (A CloudFormation extension simplifying serverless application deployment.) Provides shorthand syntax for Lambda, API Gateway, and DynamoDB, streamlining serverless workflows.
Deployment Workflow & Best Practices:
- IaC templates are typically version-controlled (e.g., Git) and integrated into CI/CD pipelines for automated deployment.
- Modularizing templates for reusability.
- Using parameters for flexibility.
- Implementing change sets for previewing infrastructure changes before application.
Scenario: A DevOps team needs to deploy a new serverless application, including Lambda functions, an API Gateway, and a DynamoDB table. They want to define this infrastructure using a simplified syntax that integrates with CloudFormation.
Reflection Question: How would you use AWS Serverless Application Model (SAM) to compose and deploy this serverless application's infrastructure efficiently, and what are the benefits of using SAM over raw CloudFormation for serverless workloads?
š” Tip: Consider how modularizing your IaC templates (e.g., separate templates for networking, compute, and data layers) can improve reusability, maintainability, and team collaboration.