Module 4: Serverless Deployment Frameworks

Module Overview

This module covers Infrastructure as Code (IaC) frameworks for building and deploying serverless applications on AWS.

Topics

• Declarative vs Imperative programming paradigms
• AWS CloudFormation (templates, stacks)
• AWS Cloud Development Kit (CDK) - imperative IaC
• AWS Serverless Application Model (SAM) - serverless-focused IaC
• AWS Amplify Framework - full-stack web/mobile
• Choosing the right framework

1. Infrastructure as Code - Two Paradigms

Resources:
  MyBucket:
    Type: AWS::S3::Bucket
    Properties:
      BucketName: my-app-data

bucket = s3.Bucket(self, "MyBucket",
    bucket_name="my-app-data",
    removal_policy=RemovalPolicy.DESTROY
)

2. AWS CloudFormation

The foundation - all other frameworks compile down to CloudFormation templates.

Workflow

Key Concepts

3. AWS Cloud Development Kit (CDK)

Define cloud infrastructure using familiar programming languages. CDK synthesizes to CloudFormation.

CDK Workflow

cdk init app --language python    # Initialize project
cdk synth                         # Generate CloudFormation template
cdk diff                          # Preview changes
cdk deploy                        # Deploy to AWS
cdk destroy                       # Tear down stack

CDK Construct Levels

Example: Lambda + API Gateway in CDK (Python)

from aws_cdk import Stack, aws_lambda as _lambda, aws_apigateway as apigw
from constructs import Construct

class MyServerlessStack(Stack):
    def __init__(self, scope: Construct, id: str, **kwargs):
        super().__init__(scope, id, **kwargs)

        # Lambda function
        handler = _lambda.Function(self, "Handler",
            runtime=_lambda.Runtime.PYTHON_3_12,
            code=_lambda.Code.from_asset("lambda"),
            handler="index.handler",
        )

        # API Gateway (L3 pattern - creates REST API + integrations)
        apigw.LambdaRestApi(self, "Endpoint", handler=handler)

4. AWS Serverless Application Model (SAM)

An extension of CloudFormation specifically designed for serverless. Adds shorthand resource types that expand into full CloudFormation on deploy.

SAM-Specific Resource Types

SAM Template Example

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31    # This line makes it SAM!

Resources:
  MyFunction:
    Type: AWS::Serverless::Function
    Properties:
      Handler: app.handler
      Runtime: python3.12
      MemorySize: 256
      Timeout: 30
      Events:
        GetItems:
          Type: Api
          Properties:
            Path: /items
            Method: get
      Policies:
        - DynamoDBCrudPolicy:
            TableName: !Ref ItemsTable

  ItemsTable:
    Type: AWS::Serverless::SimpleTable

SAM CLI Commands

sam init                    # Create new SAM project (guided)
sam build                   # Build artifacts (dependencies)
sam local invoke            # Test Lambda locally (Docker)
sam local start-api         # Run API Gateway locally
sam local generate-event    # Generate sample events (S3, SQS, etc.)
sam validate                # Validate template
sam deploy --guided         # Deploy to AWS (interactive)
sam logs -n MyFunction      # Tail CloudWatch Logs
sam sync --watch            # Hot-reload changes (dev mode)

5. AWS Amplify

Full-stack development platform for web and mobile apps. Combines frontend hosting with backend cloud services.

Amplify Gen 2 (Current - 2024+)

Amplify Gen 2 Example

// amplify/data/resource.ts
import { defineData } from '@aws-amplify/backend';
import { a } from '@aws-amplify/data-schema';

const schema = a.schema({
  Todo: a.model({
    content: a.string(),
    isDone: a.boolean(),
  }).authorization(allow => [allow.owner()]),
});

export const data = defineData({ schema });

6. Framework Comparison

Key insight: All roads lead to CloudFormation. CDK, SAM, and Amplify all generate CloudFormation templates for deployment.

7. Live Demo: SAM Build & Deploy

# Step 1: Create a new SAM project
sam init --runtime python3.12 --name my-serverless-api --app-template hello-world

# Step 2: Explore the generated files
cd my-serverless-api
cat template.yaml         # SAM template
cat hello_world/app.py    # Lambda code

# Step 3: Test locally
sam build
sam local invoke HelloWorldFunction
sam local start-api       # Start local API on port 3000
# In another terminal: curl http://localhost:3000/hello

# Step 4: Deploy to AWS
sam deploy --guided
# Follow prompts: stack name, region, confirm changes

# Step 5: Test deployed API
curl https://<API_ID>.execute-api.us-west-2.amazonaws.com/Prod/hello/

# Step 6: View logs
sam logs -n HelloWorldFunction --tail

# Step 7: Cleanup
sam delete --stack-name my-serverless-api

8. What's New (2024-2025 Updates)

• SAM Accelerate (sam sync) - Hot-reload Lambda code changes without full deploy (~seconds vs minutes)
• SAM + CDK integration - Use sam local invoke/start-api with CDK-defined Lambda functions
• Amplify Gen 2 GA - TypeScript-first, per-developer sandboxes, fullstack type safety
• CDK v2 - Single package (aws-cdk-lib), all constructs in one module, simplified imports
• SAM remote invoke - Invoke deployed Lambda functions directly from CLI
• Lambda Powertools - Structured logging, tracing, metrics built into SAM templates
• CloudFormation IaC Generator - Import existing resources into CloudFormation management

9. Module Summary