Understanding Docker Internals: Building a Container Runtime in Python

This technical guide breaks down container technology by building a simple container runtime in Python from scratch. Using Linux primitives like namespaces for isolation, cgroups for resource limits, and chroot for filesystem separation, the tutorial demonstrates how containers share the host's kernel while creating isolated environments. The implementation includes process isolation, filesystem mounting, memory limits, and basic networking, revealing that containers aren't "lightweight VMs" but clever applications of existing Linux kernel features.