homelab-frontend/TEMPORAL_IMPLEMENTATION_CHECKPOINT.md

Temporal REST API Gateway - Implementation Checkpoint

Status: In Progress - Paused for laptop sleep mode

Last Update: Current Session

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✅ What Has Been Completed

Phase 1: Design (COMPLETE)

• ✅ TEMPORAL_USAGE.md - Complete API reference (1,193 lines)
• ✅ TEMPORAL_API_DESIGN_SUMMARY.md - Design decisions (538 lines)
• ✅ 24 operations documented with examples
• ✅ TaskQueue management recommendation: Option C (Read-Only Monitor)
• ✅ Unified request/response format designed

Phase 2: Implementation (IN PROGRESS - 30%)

• ✅ Created internal/temporal/handler.go (17,337 bytes)

  • HTTP handler for /workflow endpoint
  • All 24 operations mapped to handler methods
  • Standard request/response payloads implemented
  • Helper functions for payload parsing
  • Error handling framework
  • Health check endpoint
  • Metrics endpoint stub

• ⏳ Created internal/temporal/handler_test.go (started, needs updates)

  • 30+ unit tests prepared
  • Request parsing tests
  • Operation routing tests
  • Validation tests
  • Response format tests

Status: Code compiles and basic structure is in place

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🔄 What Needs To Be Done Next

Immediate Next Steps (When Resuming)

1. Fix Test Compilation Errors

   • Update handler_test.go to match new handler.go implementation
   • Remove unused variables
   • Fix import statements

2. Run All Tests

   cd /Users/rockliang/workplace/homelab-frontend
   go test ./internal/temporal/... -v
   

3. Integrate Handler into Gateway Router

   • Update internal/server/router.go to add /workflow route
   • Update cmd/gateway/main.go to initialize Temporal handler

4. Test Integration

   # Build
   go build -o gateway ./cmd/gateway/
   
   # Test with cURL
   curl -X POST http://localhost:8080/workflow \
     -H 'Content-Type: application/json' \
     -d '{
       "action": "START_WORKFLOW",
       "namespace": "default",
       "payload": {
         "workflow_id": "test_1",
         "workflow_type": "TestWorkflow",
         "task_queue": "default"
       }
     }'
   

Phase 3: Temporal SDK Integration (Future)

When ready to connect to actual Temporal server:

1. Add gRPC Dependencies

   go get google.golang.org/grpc
   go get github.com/grpc-ecosystem/grpc-gateway/v2
   

2. Create gRPC Client Wrapper

   • Implement WorkflowServiceClient connection
   • Implement OperatorServiceClient connection
   • Add connection pooling

3. Implement Real Temporal Calls

   • Replace placeholder implementations with actual gRPC calls
   • Handle Temporal-specific errors
   • Implement timeout handling
   • Add retry logic

4. Complete Testing

   • Integration tests with Temporal server
   • Load testing
   • Error scenario testing

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📂 Files Created/Modified This Session

Created

• internal/temporal/handler.go - Main HTTP handler (17KB)
• TEMPORAL_USAGE.md - API reference (22KB)
• TEMPORAL_API_DESIGN_SUMMARY.md - Design doc (5KB)

In Progress

• internal/temporal/handler_test.go - Unit tests (needs fixing)

To Be Modified

• internal/server/router.go - Add /workflow route
• cmd/gateway/main.go - Initialize handler

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🎯 Current Implementation Status

Handler Structure

/workflow (POST)
  ├─ START_WORKFLOW ✅
  ├─ DESCRIBE_WORKFLOW ✅
  ├─ LIST_WORKFLOWS ✅
  ├─ GET_WORKFLOW_HISTORY ✅
  ├─ TERMINATE_WORKFLOW ✅
  ├─ CANCEL_WORKFLOW ✅
  ├─ SIGNAL_WORKFLOW ✅
  ├─ QUERY_WORKFLOW ✅
  ├─ RESET_WORKFLOW ✅
  ├─ UPDATE_WORKFLOW ✅
  ├─ HEARTBEAT_ACTIVITY ✅
  ├─ COMPLETE_ACTIVITY ✅
  ├─ FAIL_ACTIVITY ✅
  ├─ LIST_NAMESPACES ✅
  ├─ DESCRIBE_NAMESPACE ✅
  ├─ CREATE_NAMESPACE ✅
  ├─ UPDATE_NAMESPACE ✅
  ├─ DELETE_NAMESPACE ✅
  ├─ LIST_SEARCH_ATTRIBUTES ✅
  ├─ ADD_SEARCH_ATTRIBUTES ✅
  ├─ LIST_TASK_QUEUES ✅
  ├─ GET_CLUSTER_INFO ✅
  ├─ LIST_CLUSTER_MEMBERS ✅
  └─ GET_SYSTEM_INFO ✅

/workflow/health (GET) ✅
/workflow/metrics (GET) ✅

All operations have:

• Request validation
• Error handling
• Response formatting
• Placeholder implementations ready for gRPC integration

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🧪 Testing Plan

Unit Tests (Ready to Run)

• Request parsing validation
• Action routing
• Error handling
• Response formatting
• All 24 operations recognized

Integration Tests (Next)

• Full request/response cycle
• Error scenarios
• Edge cases

End-to-End Tests (After gRPC Integration)

• Actual Temporal server communication
• All operations with real data
• Performance testing

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📝 Quick Restart Guide

When you resume:

1. Check current state:

   cd /Users/rockliang/workplace/homelab-frontend
   git status
   

2. Fix tests:

   • Edit internal/temporal/handler_test.go
   • Remove unused variables
   • Update imports if needed
   • Run: go test ./internal/temporal/... -v

3. Integrate into gateway:

   • Edit internal/server/router.go
   • Add: case "/workflow": h.temporalHandler.ServeHTTP(w, r)
   • Edit cmd/gateway/main.go
   • Initialize: temporalHandler := temporal.NewHandler("localhost:7233")

4. Test the endpoint:

   • Build: go build -o gateway ./cmd/gateway/
   • Run: ./gateway
   • Test: curl -X POST http://localhost:8080/workflow ...

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💾 Important Files Location

/Users/rockliang/workplace/homelab-frontend/
├── TEMPORAL_USAGE.md                         # ← API Reference
├── TEMPORAL_API_DESIGN_SUMMARY.md           # ← Design Decisions
├── internal/temporal/
│   ├── handler.go                           # ← Main implementation
│   └── handler_test.go                      # ← Tests (needs fixing)
├── internal/server/
│   └── router.go                            # ← Needs /workflow route
└── cmd/gateway/
    └── main.go                              # ← Needs handler init

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🚀 Next Session Tasks

Priority Order:

1. Fix and run tests
2. Integrate into gateway
3. Test endpoint with cURL
4. Add gRPC integration
5. Full end-to-end testing

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✨ Summary

You have:

• ✅ Complete design documentation (27KB, 1,731 lines)
• ✅ Full handler implementation (24 operations)
• ✅ Test suite prepared
• ⏳ Ready for integration and gRPC connection

Everything is structured and ready to go. Just need to fix tests, integrate the handler, and test the endpoint when you resume.

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Session Time: ~2-3 hours Code Written: ~18KB of handler + tests Next Session Est.: 1-2 hours to complete Phase 2

Good luck! 🎉