Docker has led a revolution in devops and fundamentally changed the way many people build software. However, few people understand that Docker containers are not inherently secure - there are vulnerabilities at the host level that are inherited by all of the containers. Applications still have vulnerabilities, and a kernel level attack not only leaves the applications exposed but can lead to container escapes and compromise the entire system. Traditional Linux OS images do not include security protection at the kernel layer, but hardening the kernel is the simplest and surest approach to eliminating attacks targeting every layer of the computing stack. The OS, device, application and containers all inherit protection from the hardened kernel for entire classes of cyber attacks.