Worklog Week 10

Week 10 Objectives

  • Stabilize AWS SAM/Serverless deployment environment and resolve critical issues.
  • Focus on debugging core problems: CORS configuration, template validation errors, and API response formatting.
  • Integrate Frontend/Backend to enable end-to-end testing on user interface.
  • Complete basic Read and Delete functionalities with proper error handling.
  • Participate in AWS Cloud Mastery Series event to receive expert guidance and address project challenges.
  • Workshop: Load Balancer Configuration - Set up Application Load Balancer for traffic distribution.

Tasks Completed This Week

DayTaskStart DateCompletion DateResources
Mon- Debug CORS: Analyze CORS configuration in API Gateway (CORS headers, preflight OPTIONS requests) and Lambda response headers to allow Frontend access.
- Fix template validation errors: Review and optimize template.yaml file to prevent deployment loop errors and resource dependency issues during sam deploy.		11/11/202411/11/2024API Gateway/CORS Documentation
Tue- Strengthen Read function (Retrieving flashcard sets): Ensure data is queried from DynamoDB correctly and returned in proper JSON format for Frontend consumption.
- Implement error handling for missing records and invalid queries.
- Add logging for debugging purposes.		12/11/202412/11/2024DynamoDB Query Documentation
Wed- Frontend Integration: Begin combining Frontend codebase with project and test deployed API endpoints.
- Successfully display flashcard sets list on user interface.
- Test API connectivity and data rendering in React/Vue components.
- Workshop Activity: Create Application Load Balancer (ALB) in public subnets and configure target groups for ECS services.		13/11/202413/11/2024Frontend Framework Documentation, Workshop 5.5
Thu- Deploy and test Delete function (Removing flashcard sets).
- Encountered Error: Identified authorization issue with Cognito User Sub ID when executing Delete function - Lambda unable to extract/process Sub ID from Cognito token correctly.
- Begin troubleshooting authentication flow.		14/11/202414/11/2024AWS Cognito Documentation
Fri- Participation in AWS Cloud Mastery Series:
  + Received expert guidance and clarified questions regarding Serverless architecture, Lambda best practices, and authentication patterns.
- Analyze Update/Delete errors: Apply mentor guidance to resolve authorization issues and Cognito token parsing problems.
- Document solutions for future reference.		15/11/202415/11/2024Mentor, AWS Cloud Mastery Series

Week 10 Achievements

  • Successfully fixed CORS error and stabilized SAM deployment process (mitigated template validation errors).
  • Participated in AWS Cloud Mastery Series event and gathered essential information to solve major project blockers.
  • Completed Frontend and Backend integration, achieving first functional user interface for end-to-end testing.
  • Successfully deployed Read (Retrieving flashcard sets) and Delete (Removing flashcard sets) functionalities, operational on web interface.
  • Identified and gained direction to solve critical bottlenecks:
    • Authorization error: Lambda fails to retrieve/incorrectly process Cognito Sub ID from JWT token, affecting privileged operations
    • Update function dependency: Requires proper authentication flow and token validation
  • The project has transitioned to basic user testing phase with working CRUD operations.
  • Established debugging workflow and error handling patterns for team.

Workshop Progress - Load Balancer Configuration:

  • Created Application Load Balancer (ALB) in public subnets across two AZs
  • Configured target groups for Frontend (port 3000) and Backend (port 8080) ECS services
  • Set up health checks for automatic unhealthy target removal
  • Configured SSL/TLS termination using ACM certificates
  • Integrated ALB with Route 53 for DNS routing
  • Implemented listener rules for path-based routing (Frontend: /, Backend: /api/*)
  • Configured security groups to allow ALB traffic to ECS tasks

Key Takeaways:

  • CORS requires proper configuration in both API Gateway and Lambda response headers
  • Cognito JWT tokens must be properly decoded to extract user identity (Sub ID)
  • Frontend-Backend integration requires careful attention to API contracts and data formats
  • Error handling and logging are essential for debugging production issues
  • AWS Cloud Mastery Series provides valuable real-world insights from experienced practitioners
  • ALB provides intelligent traffic distribution and automatic failover
  • Health checks ensure only healthy targets receive traffic
  • SSL/TLS termination at ALB reduces computational load on backend services