Add Multi-Source API Example

[sebsto]

This PR adds a new example demonstrating how to build a Lambda function that handles requests from multiple sources (Application Load Balancer and API Gateway V2) using a single handler.

What's New

New Example: Examples/MultiSourceAPI

A Lambda function that:

• Implements StreamingLambdaHandler to accept raw ByteBuffer events
• Dynamically decodes events as either ALBTargetGroupRequest or APIGatewayV2Request
• Returns appropriate responses based on the detected event source
• Demonstrates handling multiple AWS service integrations with a single function

Key Features

• Type-safe event detection: Uses Swift's Decodable to identify the event source at runtime
• Streaming response: Implements StreamingLambdaHandler for efficient response handling
• Complete deployment: Includes SAM template with both ALB and API Gateway V2 infrastructure
• Production-ready: Full VPC setup with subnets, security groups, and load balancer configuration

Files Added

• Examples/MultiSourceAPI/Sources/main.swift - Lambda handler implementation
• Examples/MultiSourceAPI/Package.swift - Swift package configuration
• Examples/MultiSourceAPI/template.yaml - SAM deployment template with ALB and API Gateway V2
• Examples/MultiSourceAPI/README.md - Documentation with build, deploy, and test instructions
• Updated CI to include the new example

Use Case

This pattern is useful when you want to:

• Expose the same Lambda function through multiple AWS services
• Reduce code duplication by handling similar requests from different sources
• Maintain a single codebase for multi-channel APIs

[Copilot]

Pull Request Overview

This PR adds a new MultiSourceAPI example that demonstrates a Lambda function capable of handling requests from both Application Load Balancer (ALB) and API Gateway V2. The handler receives raw ByteBuffer events and uses pattern matching with type-safe decoding to determine the event source and return the appropriate response.

Key changes:

• Implements a StreamingLambdaHandler that decodes incoming events as either ALBTargetGroupRequest or APIGatewayV2Request
• Includes complete AWS infrastructure setup with VPC, subnets, ALB, and API Gateway V2
• Adds the new example to the CI workflow

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
Examples/MultiSourceAPI/Sources/main.swift	Core Lambda handler implementing multi-source event processing logic
Examples/MultiSourceAPI/Package.swift	Swift package manifest defining dependencies and build configuration
Examples/MultiSourceAPI/template.yaml	SAM template defining AWS infrastructure including ALB and API Gateway
Examples/MultiSourceAPI/samconfig.toml	SAM CLI configuration for deployment
Examples/MultiSourceAPI/README.md	Documentation explaining usage and deployment
Examples/MultiSourceAPI/.gitignore	Standard Swift project ignore patterns
Examples/MultiSourceAPI/.aws-sam/build/template.yaml	Generated SAM build artifact
Examples/MultiSourceAPI/.aws-sam/build.toml	Generated SAM build metadata
.github/workflows/pull_request.yml	Updated CI workflow to include new example

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.