Lambda Functions Package¶

Overview¶

The packages/lambda_functions/ directory contains AWS Lambda functions that provide serverless functionality for the Delta platform. These functions handle specific tasks like message processing and API authorization.

Lambda Functions¶

AI Hub SQS Processor¶

Package: @delta/aihub-sqs-processor

Purpose¶

Processes messages from AWS SQS queues
Triggers AI Hub processing tasks
Manages ECS task execution for AI workloads

Technology Stack¶

Runtime: Node.js with TypeScript
Build Tool: esbuild for optimized bundling
AWS Services: SQS, ECS
Logging: Integration with @delta/common

Key Features¶

SQS message processing
ECS task management
Error handling and retry logic
Optimized bundle size for Lambda

Dependencies¶

AWS SDK for SQS and ECS operations
@delta/common for shared utilities
No external HTTP client (uses AWS SDK for service communication)

Build Process¶

# Build optimized bundle
yarn run build

# Start local development
yarn run dev

The build process uses esbuild to create a minified, bundled JavaScript file optimized for Lambda execution.

Configuration¶

Entry Point: src/index.ts
Output: dist/index.js (bundled and minified)
External Dependencies: AWS SDK modules are marked as external
Source Maps: Enabled for debugging

API Gateway Authorizer¶

Package: @delta/api-gateway-authorizer

Purpose¶

Provides custom authorization for API Gateway endpoints
Validates authentication tokens
Manages access control policies

Technology Stack¶

Runtime: Node.js with TypeScript
Build Tool: esbuild for optimized bundling
AWS Services: SSM (Systems Manager)
Type Safety: AWS Lambda types

Key Features¶

Token validation and verification
Policy generation for API Gateway
Integration with AWS SSM for configuration
Lightweight and fast execution

Dependencies¶

AWS SDK for SSM operations
AWS Lambda types for TypeScript support

Build Process¶

# Build optimized bundle
yarn run build

Similar to the SQS processor, this uses esbuild for optimal Lambda performance.

Configuration¶

Entry Point: src/index.ts
Output: dist/index.js (bundled and minified)
Source Maps: Enabled for debugging

Development¶

Local Development¶

AI Hub SQS Processor¶

cd packages/lambda_functions/aiHubSqsProcessor

# Install dependencies
yarn install

# Start local development with debugging
yarn run dev

The development script uses a custom local development setup that simulates SQS message processing.

API Gateway Authorizer¶

cd packages/lambda_functions/apiGatewayAuthorizer

# Install dependencies
yarn install

# Build the function
yarn run build

Testing¶

Both Lambda functions can be tested locally using:

AWS SAM CLI for local Lambda simulation
LocalStack for AWS service mocking
Unit tests with mocked AWS services

Environment Variables¶

AI Hub SQS Processor¶

AWS region and credentials
SQS queue URLs
ECS cluster and task definitions
Logging configuration

API Gateway Authorizer¶

AWS region and credentials
SSM parameter paths
Authentication service endpoints

Deployment¶

AWS Lambda Deployment¶

Both functions are designed for deployment to AWS Lambda:

Build: Create optimized bundles using esbuild
Package: Zip the dist/ directory with dependencies
Deploy: Upload to AWS Lambda using AWS CLI, CDK, or Terraform

Infrastructure as Code¶

The Lambda functions are typically deployed using:

AWS CDK for TypeScript-based infrastructure
Terraform for declarative infrastructure
AWS SAM for serverless application deployment

Monitoring and Logging¶

CloudWatch Integration¶

Automatic log streaming to CloudWatch Logs
Custom metrics for function performance
Error tracking and alerting

Observability¶

Distributed tracing with AWS X-Ray
Performance monitoring
Cost optimization tracking

Best Practices¶

Performance Optimization¶

Minimal bundle sizes using esbuild
External AWS SDK dependencies
Connection reuse and pooling
Cold start optimization

Security¶

Least privilege IAM roles
Secure environment variable handling
Input validation and sanitization
Error message sanitization

Reliability¶

Proper error handling and retries
Dead letter queue configuration
Timeout and memory optimization
Graceful degradation

Architecture Integration¶

AI Hub SQS Processor Flow¶

SQS message triggers Lambda function
Function processes message content
Initiates ECS task for AI processing
Monitors task completion
Handles success/failure scenarios

API Gateway Authorizer Flow¶

API Gateway receives request
Authorizer Lambda validates token
Returns authorization policy
API Gateway allows/denies request
Logs authorization decisions

Lambda Functions Package¶

Overview¶