Common Ingress Errors in Kubernetes Ingress is a powerful Kubernetes resource that manages external access to services within your cluster. However, it often becomes a source of confusion and frustration due to misconfigurations or overlooked details. This article outlines the most common Ingress errors and how to fix them. 1. Misconfigured Annotations Annotations can control features like URL rewrites, authentication, and rate limiting. Incorrect annotations may silently break your setup. ...

Basic iptables Commands Every DevOps Engineer Should Know iptables is a powerful command-line utility for configuring the Linux kernel firewall. It is widely used for managing network traffic and securing Linux-based systems. Why Use iptables? Block unwanted traffic Allow specific ports Forward or redirect traffic Protect services from unauthorized access Basic iptables Syntax iptables -[A|D|I|R|L] [CHAIN] [OPTIONS] -A: Append a rule -D: Delete a rule -I: Insert a rule -R: Replace a rule -L: List rules Common Chains INPUT: Packets destined to the host OUTPUT: Packets sent from the host FORWARD: Packets routed through the host Examples List All Rules iptables -L -v -n Allow Incoming SSH (Port 22) iptables -A INPUT -p tcp --dport 22 -j ACCEPT Drop All Incoming Traffic By Default iptables -P INPUT DROP iptables -P FORWARD DROP iptables -P OUTPUT ACCEPT Allow Loopback and Established Connections iptables -A INPUT -i lo -j ACCEPT iptables -A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT Delete a Rule iptables -D INPUT -p tcp --dport 22 -j ACCEPT Saving and Restoring Rules Save Rules iptables-save > /etc/iptables/rules.v4 Restore Rules iptables-restore < /etc/iptables/rules.v4 Conclusion Understanding iptables helps you take full control over traffic flow in and out of your Linux systems. These basic commands will help you secure your infrastructure and troubleshoot network issues. ...

Kubernetes supports two main kube-proxy modes: iptables and ipvs. Which one should you use? 1. What is kube-proxy? kube-proxy manages network rules on Kubernetes nodes, allowing communication between services and pods. It can operate in different modes: iptables, ipvs, and userspace (deprecated). 2. iptables Mode Default and widely supported Implements rules using iptables NAT chains Pros: Simpler No extra kernel modules required Easier to debug Cons: Performance degrades with many services Sequential rule processing 3. IPVS Mode Based on Linux IP Virtual Server (part of LVS) Uses a hash table for rules → faster performance Pros: Better performance for large-scale clusters Supports connection-level load balancing algorithms (round-robin, least connections, etc.) Cons: Requires ip_vs kernel modules Slightly more complex setup 4. Switching to IPVS Check kernel support: ...

Overview Node.js has become a leading platform for building scalable and performant backend applications. With its rich ecosystem, multiple frameworks have emerged to simplify development and promote best practices. This article provides a comparison of the most popular Node.js frameworks — their strengths, trade-offs, and use cases. 1. Express.js Pros: Minimal and flexible Huge community and ecosystem Middleware architecture Cons: Lacks built-in structure Manual setup for many things Example: const express = require('express'); const app = express(); app.get('/', (req, res) => res.send('Hello Express!')); app.listen(3000); 2. Koa.js Created by the same team behind Express, Koa aims to be more modern and lightweight. ...

Introduction OpenTelemetry is an open-source observability framework for cloud-native software, providing a set of APIs, libraries, agents, and instrumentation to collect metrics, logs, and traces. It’s a powerful tool for gaining insight into distributed systems and performance bottlenecks. In this article, we’ll walk through what OpenTelemetry is, why you should use it, and how to set it up step-by-step. Why OpenTelemetry? Unified Observability: One standard for logs, metrics, and traces. Vendor-Neutral: Export data to systems like Prometheus, Jaeger, or commercial APMs. Extensible: Support for multiple languages and platforms. Step-by-Step Guide Step 1: Install the Collector Use the OpenTelemetry Collector to receive, process, and export telemetry data. ...