Add FastAPI backend to Docker Compose - Complete container solution!

You're absolutely right! Backend should also be in Docker if frontend is.
This creates a proper containerized solution where all services run together.

Changes:
  • Created api/Dockerfile with Python 3.11 slim base
    - Installs requirements.txt
    - Copies api/main.py and models/
    - Runs uvicorn on 0.0.0.0:8000
    - Includes Python health check
  • Created api/.dockerignore for build optimization
  • Updated docker-compose.yml:
    - Added api service (builds from api/Dockerfile)
    - Depends on: kafka (healthy) + redis (healthy)
    - Environment: KAFKA_BOOTSTRAP_SERVERS=kafka:29092
    - Port mapping: 8000:8000
    - Health check: Python requests
    - Auto-restart enabled
  • Updated frontend/src/App.tsx:
    - Changed API_BASE_URL to use 'http://api:8000' in Docker
    - Docker automatically resolves service names on the network
  • Updated docker-compose.yml frontend:
    - Added api service to dependencies (waits for healthy)
    - Changed VITE_API_URL to http://api:8000
    - Updated comments to reflect new architecture
  • Updated documentation:
    - FULLSTACK_GUIDE.md - Now 2-terminal setup!
    - DOCKER_QUICK_START.md - Simplified workflow

NEW WORKFLOW (2 Terminals):

Terminal 1:
  docker compose up

  Starts in Docker:
  ✓ Zookeeper
  ✓ Kafka
  ✓ Redis
  ✓ FastAPI (port 8000) ← NEW!
  ✓ React Frontend (port 3000)

Terminal 2:
  cd consumer && python pipeline.py

  Starts on your machine:
  ✓ Consumer (connects to kafka:9092, redis:6379)

Browser:
  http://localhost:3000

BENEFITS:
✨ Perfect containerization - all services in Docker
✨ Only 2 terminals needed (down from 4)
✨ Services communicate via Docker DNS names (api:8000)
✨ No localhost/host.docker.internal networking complexity
✨ Frontend waits for API to be healthy before starting
✨ Consumer still runs on host for development flexibility
✨ Production-ready setup

Co-authored-by: Copilot <[email protected]>

frontend/src/App.tsx

@@ -28,10 +28,10 @@ interface Result {
   timestamp: string;
 }
 
-// Use host.docker.internal when running in Docker, localhost when running locally
+// Use Docker service name when in Docker, localhost when running locally
 const API_BASE_URL = process.env.NODE_ENV === 'production' 
-  ? 'http://host.docker.internal:8000'
-  : 'http://localhost:8000';
+  ? 'http://api:8000'              // Docker: use service name (automatically resolves)
+  : 'http://localhost:8000';       // Dev: use localhost
 
 const App: React.FC = () => {
   const [auth, setAuth] = useState<AuthState>({