Worker API Gateway

Worker API Gateway Knowledge

Request Flow Chain

Browser → Nginx (port 80) → API Gateway (port 9000) → Backend Service

Nginx Configuration

Location: /etc/nginx/sites-enabled/flowmaster on the dev server

Nginx Routes

• / → frontend-nextjs ClusterIP (look up live)
• /api/ → api-gateway ClusterIP (look up live) — preserves /api/ prefix
• /ws/ → websocket-gateway ClusterIP (look up live)

Critical Behavior

Nginx preserves the /api/ prefix when proxying to the API Gateway:

• Browser request: GET /api/v1/processes
• Gateway receives: GET /api/v1/processes (prefix intact)
• Gateway rewrites per routing rules (see below)

API Gateway Routing

Tech Stack: Python/FastAPI (NOT Node.js) Port: 9000 Health Endpoint: /health

Routing Rules

Gateway routes are stored in ConfigMap: gateway-config (routes.yaml)

Routing Pattern:

/v1/{service}/* → rewrites to /api/v1/{path} on target service

Example Routes:

- path: /v1/process-design/*
  target: process-design:9003
  rewrite: /api/v1/processes/$1

- path: /v1/execution/*
  target: execution-engine:9005
  rewrite: /api/v1/execution/$1

- path: /v1/scheduling/*
  target: scheduling:9008
  rewrite: /api/v1/schedules/$1

Request Flow Example

1. Browser: GET /api/v1/processes
2. Nginx: Proxies to api-gateway:9000/api/v1/processes
3. Gateway: Receives /api/v1/processes, matches route /v1/process-design/*
4. Gateway: Rewrites to /api/v1/processes and proxies to process-design:9003
5. Backend: process-design handles /api/v1/processes

ConfigMap Management

View Current Routes

ssh dev-01-root "kubectl get cm gateway-config -n flowmaster -o yaml"

View Just routes.yaml

ssh dev-01-root "kubectl get cm gateway-config -n flowmaster -o jsonpath='{.data.routes\.yaml}'"

Edit Routes

ssh dev-01-root "kubectl edit cm gateway-config -n flowmaster"

Restart Gateway After Changes

ssh dev-01-root "kubectl rollout restart -n flowmaster deploy/api-gateway"

ClusterIP Endpoints

WARNING: ClusterIPs are dynamic and will change if services are recreated. Always look them up live:

ssh dev-01-root "kubectl -n flowmaster get svc"

If Services Are Recreated

1. Run: kubectl -n flowmaster get svc
2. Find new ClusterIPs for frontend, api-gateway, websocket-gateway
3. Update /etc/nginx/sites-enabled/flowmaster
4. Reload Nginx: systemctl reload nginx

Gateway Configuration Files

ConfigMap Data Keys:

• routes.yaml - Service routing rules
• middleware.yaml - Request/response middleware (if present)
• auth.yaml - Authentication/authorization rules (if present)

Health Check

Gateway Health

ssh dev-01-root "kubectl exec -n flowmaster deploy/api-gateway -- wget -qO- http://localhost:9000/health"

Check Gateway Logs

ssh dev-01-root "kubectl logs -n flowmaster deploy/api-gateway --tail=50"

Debugging Routes

If Route Not Working

1. Check Nginx config: ssh dev-01-root "cat /etc/nginx/sites-enabled/flowmaster"
2. Check gateway logs: kubectl logs -n flowmaster deploy/api-gateway
3. Check ConfigMap: kubectl get cm gateway-config -n flowmaster -o yaml
4. Verify backend service is running: kubectl -n flowmaster get pods | grep <service-name>
5. Test directly to backend: kubectl port-forward -n flowmaster svc/<service-name> 9003:9003

Key Facts

• Gateway is FastAPI (Python), not Node.js
• Nginx preserves /api/ prefix in the proxying step
• Routes in ConfigMap control actual backend service mapping
• ClusterIPs are dynamic (look them up live, document if changed)
• Always restart gateway after ConfigMap changes
• WebSocket traffic goes through dedicated websocket-gateway service

For live ClusterIPs and service endpoints, use commander-mcp: get_context_services, get_context_ports