Container Security Toolkit: Container Security Guide

Container Security Guide A comprehensive approach to securing containers from build to runtime. Datanest Digital — datanest.dev Table of Contents Image Hardening Vulnerability Scanning Pipeline Policy Enforcement Runtime Security CI/CD Integration Compliance Mapping Incident Response Image Hardening Principle: Minimal, Immutable, Non-Root Every container image should follow three principles: Minimal: Include only what the application needs to run. No shells, no package managers, no debugging tools in production images. Immutable: Never patch running containers. Rebuild and redeploy. Non-root: Never run as UID 0. Multi-Stage Builds Multi-stage builds are the foundation of hardened images. Build tools, compilers, and development dependencies never reach the final image: # Build stage — has gcc, make, pip, etc. FROM python:3.12-slim AS builder COPY requirements.txt . RUN pip install --prefix=/install -r requirements.txt # Production stage — only runtime dependencies FROM python:3.12-slim