Build 5: Production Ingestion Microservice

# Build 5: Production Ingestion Microservice ## Scenario Build a production FastAPI service that exposes ingestion and processing endpoints for the scraper (Build 2) and stream processor (Build 3). *(Note: For full-stack relational database modeling, OAuth2 authentication, and Stripe payments, see Course 24: Backend Engineering with FastAPI. This build focuses on ingestion architecture and containerization).* ## Requirements 1. **API Endpoints:** - `POST /api/v1/ingest`: Accepts JSON batch payloads, validates with Pydantic v2, and queues stream processing. - `GET /health/live` & `GET /health/ready`: Liveness and readiness probes. 2. **12-Factor Configuration:** Use Pydantic `BaseSettings` reading environment variables with strict validation. 3. **Structured Request Logging:** Middleware generating a unique `X-Request-ID` and logging JSON metrics for every HTTP request. 4. **Containerization:** Write a multi-stage, non-root `Dockerfile` producing a lean production container image (<150MB). ## Starter Code Layout ``` build-5-fastapi-service/ ├── Dockerfile ├── pyproject.toml ├── src/ │ └── service/ │ ├── __init__.py │ ├── main.py # FastAPI app & routing │ ├── config.py # Pydantic BaseSettings │ ├── middleware.py # Request ID & JSON logger │ └── schemas.py # Ingestion payload schemas └── tests/ └── test_service.py # TestClient test cases ``` ## Verification Command ```bash pytest tests/test_service.py -v docker build -t ingestion-service:latest . ``` ## 100-Point Evaluation Rubric - **FastAPI Endpoints & Validation (30 pts):** Pydantic schemas, dependency injection, proper HTTP status codes. - **12-Factor Config (25 pts):** Typed settings with default overrides from `.env`. - **Middleware & Observability (25 pts):** Request ID propagation, structured JSON logs. - **Production Dockerfile (20 pts):** Multi-stage build, non-root user, slim base image.