DevOps

Docker has revolutionized software development and deployment by providing lightweight, portable containers that package applications and their dependencies together. But how exactly does Docker work under the hood to achieve this isolation and efficiency? This article takes a comprehensive look at Docker’s internal architecture, explaining the key components and how they interact to create and run containers. Table of Contents Introduction Docker’s Client-Server Architecture Key Docker Components Docker CLI Docker Daemon (dockerd) Container Runtime (containerd and runc) Linux Kernel Features How Docker Creates and Runs a Container Filesystem Management with OverlayFS Networking and Isolation Resource Management via cgroups Conclusion Introduction Docker containers provide isolated environments that behave like virtual machines but share the host OS kernel, making them highly efficient. This is achieved through a combination of Linux kernel features, container runtimes, and Docker’s own architecture. Understanding these layers helps in optimizing container usage and troubleshooting complex issues. ...

Introduction GitHub Pages is a fantastic starting point for static sites. But as your needs grow—zero-downtime deploys, branch previews, global edge performance, custom headers and redirects, or serverless functions—you might want to graduate to Cloudflare Pages. In this step-by-step guide, you’ll learn how to migrate cleanly from GitHub Pages to Cloudflare Pages with minimal or zero downtime, while preserving SEO, URLs, and performance. We’ll cover: Preparing your repository (Jekyll/Hugo/Eleventy/Next/Astro/etc.) Configuring Cloudflare Pages builds and environments Switching DNS with no downtime Preserving links via redirects and canonical URLs Handling SPA routing, caching, headers, and forms Rollbacks, previews, and common pitfalls If you follow along, you can ship your site on Cloudflare Pages the same day. ...

Introduction Cross-Origin Resource Sharing (CORS) is one of the most misunderstood parts of modern web development. It sits at the intersection of browsers, HTTP, and security, and when it goes wrong you often see opaque errors like “CORS policy: No ‘Access-Control-Allow-Origin’ header…”. This guide takes you from zero to hero: you’ll learn the mental model behind CORS, how the browser enforces it, how to configure servers correctly across popular stacks, how to optimize performance, and how to avoid common security pitfalls. ...

Nginx is one of the most popular open-source web servers in the world, widely used not only to serve static content but also as a reverse proxy, load balancer, and HTTP cache. This comprehensive tutorial will guide you step-by-step from the basics of installing Nginx to configuring advanced features, helping you become proficient in managing and optimizing it for your projects. Table of Contents Introduction to Nginx Installing Nginx Understanding Nginx Architecture Basic Configuration and Serving Static Content Configuring Reverse Proxy and Load Balancing Optimizing Nginx Performance Setting Up HTTPS with SSL/TLS Advanced Configurations and Use Cases Useful Commands for Managing Nginx Further Resources Conclusion Introduction to Nginx Nginx (pronounced “Engine-X”) is a high-performance web server designed to handle many concurrent connections efficiently. Unlike traditional web servers, it uses an event-driven, asynchronous architecture, which makes it well suited for high-traffic websites and applications. ...

Introduction HAProxy is the de facto open-source load balancer and reverse proxy for high-traffic websites, APIs, and microservices. It’s fast, battle-tested, extremely configurable, and equally at home terminating TLS, routing based on headers or paths, defending against abuse, or load balancing TCP streams. This zero-to-hero guide takes you from first principles to production-ready configurations. We’ll cover installation, core concepts, practical configuration patterns, TLS, health checks, observability, advanced features like ACLs and stick tables, and safe reloads—with copy-and-pasteable examples. ...