container-orchestration

# Container Orchestration > Facts verified as of 2026-07. Docker and Kubernetes patterns for containerized applications. ## Dockerfile Best Practices ```dockerfile # Use specific version, not :latest FROM python:3.11-slim AS builder # Set working directory WORKDIR /app # Copy dependency files first (better caching) COPY requirements.txt . RUN pip install --no-cache-dir -r requirements.txt # Copy application code COPY src/ ./src/ # Production stage (multi-stage build) FROM python:3.11-slim WORKDIR /app # Create non-root user RUN useradd --create-home appuser USER appuser # Copy from builder COPY --from=builder /app /app # Set environment ENV PYTHONUNBUFFERED=1 # Health check HEALTHCHECK --interval=30s --timeout=3s \ CMD curl -f http://localhost:8000/health || exit 1 EXPOSE 8000 CMD ["python", "-m", "uvicorn", "src.main:app", "--host", "0.0.0.0"] ``` ### Dockerfile Rules ``` DO: - Use specific base image versions - Use multi-stage builds - Run as non-root user - Order commands by change frequency - Use .dockerignore - Add health checks DON'T: - Use :latest tag - Run as root - Copy unnecessary files - Store secrets in image - Install dev dependencies in production ``` ## Docker Compose ```yaml # docker-compose.yml version: "3.9" services: app: build: context: . dockerfile: Dockerfile ports: - "8000:8000" environment: - DATABASE_URL=postgres://user:pass@db:5432/app depends_on: db: condition: service_heal...