Containers look like lightweight VMs, but they’re really just processes wrapped in namespaces and cgroups. We unpack mount, PID, network, UTS, IPC, user, and cgroup namespaces, trace how runtimes like containerd wire them together, and explore the failure modes every SRE should know.
Namespaces are the unsung kernel feature behind every container runtime. This post walks through the eight namespace types, how they appear in the kernel, and how Docker, Kubernetes, and runc compose them into the isolation boundary you trust in production.
This post unpacks the mechanics of Linux namespaces, showing how they enable lightweight isolation in Docker and Kubernetes, and offers practical patterns for building secure container runtimes.
Introduction: The Shift from Virtual Machines to Containers In the early days of software deployment, the mantra was “it works on my machine.” Developers would spend weeks building an application, only for it to fail in production due to subtle differences in operating system versions, library dependencies, or environment configurations. This friction between development and operations led to the birth of the DevOps movement and the rise of containerization. At the heart of this revolution is Docker. Docker has transformed how we build, ship, and run applications by providing a consistent environment across the entire software development lifecycle (SDLC). Whether you are a solo developer or part of a massive enterprise, understanding Docker is no longer an optional skill—it is a fundamental requirement for modern software engineering. ...
Introduction Docker has revolutionized application deployment by enabling developers to package applications and their dependencies into lightweight, portable containers. However, containers don’t exist in isolation—they need to communicate with each other, with the host system, and with external networks. This is where Docker networking comes in. Understanding how Docker networking works is essential for building scalable, secure, and efficient containerized applications. Docker networking is the system that enables containers to communicate with each other, the host, and external networks[3]. It defines how data flows between containers and provides the infrastructure necessary for multi-container applications to function seamlessly. Whether you’re running a simple web application or a complex microservices architecture, mastering Docker networking is crucial for success. ...