DevOps

Introduction Redis Access Control Lists (ACLs) let you define who can do what across commands, keys, and channels. Introduced in Redis 6 and expanded since, ACLs are now the standard way to secure multi-tenant applications, microservices, and administrative workflows without resorting to a single, global password. In this guide, you’ll learn how Redis ACLs work, how to design least-privilege access for different use cases, how to manage ACLs safely in production (files, replication, rotation), and how to audit and test your permissions before you deploy. ...

Introduction Port exhaustion is a pernicious, often misunderstood failure mode that can bring a high-traffic Nginx deployment to its knees. The symptoms are intermittent and confusing—spiky 5xx error rates, “Cannot assign requested address” in logs, and upstream timeouts—yet the root cause is usually simple: you ran out of usable ephemeral ports for outbound connections. In this article, we’ll explain what port exhaustion is and why Nginx is especially prone to it in reverse-proxy scenarios. We’ll cover how to diagnose it accurately, provide practical fixes at the Nginx and OS levels, and offer architectural strategies to prevent it from recurring. Whether you’re running bare metal, in containers, or behind a cloud NAT gateway, this guide will help you understand and solve Nginx port exhaustion. ...

Introduction Distributed systems run everything from streaming platforms to payment networks and logistics providers. Building them for production requires more than just connecting services—you need to understand failure modes, consistency models, data and network behavior, and how to operate systems reliably at scale. This article provides a high-level but comprehensive tour of the essential concepts you need in practice. It favors pragmatic guidance, proven patterns, and the “gotchas” teams hit in real-world environments. ...

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. ...