Linux Privileges: Understanding Sudo vs Root

When I started as an SRE, I wish someone had given me a simple guide to automate the boring stuff as I spent hours manually cleaning logs, checking servers, and restarting stuck pods. So I built one myself. This repo is my humble attempt to give back – a simple, practical guide for anyone stepping into Linux, Kubernetes, or site reliability. Inside you'll find: 📁 A folder structure that makes sense   📄 Real bash scripts you can run today   📚 A README that explains each one  No fluff. Just tools I use daily. This is the "starter kit" I would have killed for 5 years ago. 🔗 https://lnkd.in/eMrdTn4C Also please let me know if you have another idea to add on this #SRE #Linux #Kubernetes #Mentorship #Automation #Bash

🚀 Day 4/30 – DevOps Journey Today I explored advanced Linux commands that are very useful in real-world DevOps tasks. 💡 Key Learnings: grep command to search text inside files Pipe (|) to combine multiple commands cat command to read file content echo command to create and modify files 🔍 Also explored: grep options like -i (ignore case), -n (line numbers) Filtering and processing command outputs using pipes 💻 Hands-on: Created files and added content using echo Searched specific words using grep Combined commands to filter output efficiently 📈 How I Improved: Gained better understanding of command-line usage Learned how to combine commands instead of running them separately Improved my ability to analyze file content quickly Built confidence working with Linux terminal 📌 Key Takeaway: Combining commands using pipes makes Linux very powerful for tasks like log analysis, debugging, and automation. 🔗 GitHub (Day 4 work): https://lnkd.in/gJVDpbRF Learning step by step and improving every day 💪 #DevOps #Linux #Automation #Cloud #LearningJourney #30DaysChallenge

Day 6 of becoming a DevOps Engineer Navigating the Linux Filesystem - A Must-Know for Every Tech Learner In Linux, everything is organized—and everything lives somewhere for a reason. Understanding the Linux filesystem isn’t just theory. It’s a core skill for system administration, troubleshooting, and working confidently in any Linux environment. Here’s a simplified breakdown: 🔹 Core System Directories / – The root of everything. Every file and directory starts here. /bin & /usr/bin – Essential command tools like ls, cp, cat. /sbin & /usr/sbin – System-level commands (used for admin tasks). /etc – Configuration files for the system and applications. /home – Personal space for users. /root – Home directory for the superuser. /boot – Files required to start the system. 🔹 Dynamic & System Directories /dev – Represents hardware devices. /proc & /sys – Real-time system and process information. /var – Frequently changing data like logs and web files. /tmp – Temporary files (often cleared on reboot). /opt – Optional or third-party software. /lib & /usr/lib – Shared libraries for programs. /media & /mnt – Mount points for external drives. /run – Runtime system data since last boot. Key Insight: The Linux filesystem follows a structured standard, which means once you understand it, you can navigate almost any Linux system with confidence. For me, this is more than just learning directories… It’s about building a solid foundation for DevOps and Cloud Engineering. #BuildInPublic #TechJourney #Linux #DevOps #CloudComputing #TechInAfrica #TechLearning #SystemAdministration #ContinuousLearning #TSAcademy #30DaysOfLearning

🚀 #100DaysOfDevOps by KodeKloud | Day 4 🔐 Day 4: Script Execution Permissions Today I worked on a simple yet important Linux concept — file permissions and how they impact script execution. 🧩 Task I had to grant executable permissions to a script: /tmp/xfusioncorp.sh on App Server 1, ensuring that all users can execute it. 🛠️ Steps I followed 1️⃣ Switched to root user from jump host: sudo -i 2️⃣ Connected to App Server 1: ssh stapp01 3️⃣ Checked existing permissions: ls -l /tmp/xfusioncorp.sh 4️⃣ Granted proper permissions: chmod 755 /tmp/xfusioncorp.sh 5️⃣ Verified the result: -rwxr-xr-x ⚠️ Issues I encountered ❌ Initially used: chmod a+x But it resulted in: r--r-x--x 👉 The owner didn’t have proper execute permission in expected format 👉 This caused the task validation to fail 💡 Learned that just adding execute (x) is not always enough — sometimes I need to explicitly set correct permission structure ✅ Key Learning ✔ File permissions matter more than they look ✔ Understanding rwx is crucial for Linux & DevOps ✔ Always verify using ls -l before submitting ✔ When in doubt, chmod 755 is a safe and common approach 🔥 Small task, big learning! If you're starting your DevOps journey, I highly recommend KodeKloud for hands-on labs 👇 https://lnkd.in/deg5ZDcV #DevOps #Linux #KodeKloud #LearningInPublic #CloudComputing #100DaysChallenge

🚀 Day 3/30 – DevOps Journey Today I focused on understanding Linux file permissions, which play a critical role in system security and access control. 💡 Key Learnings: Types of permissions: Read (r), Write (w), Execute (x) Permission groups: User, Group, Others Understanding permission format (e.g., rwxr-xr-x) Using chmod to modify permissions Basics of chown for ownership management 💻 Hands-on: Created files and checked permissions using ls -l Modified permissions using chmod Observed how access changes based on permission settings 📌 Key Takeaway: Linux permissions are essential for securing systems and managing user access in real-world DevOps environments. 🔗 GitHub (Day 3 work): https://lnkd.in/gJVDpbRF Step by step, building strong fundamentals 💪 #DevOps #Linux #Permissions #AWS #LearningJourney #30DaysChallenge

If you’re learning Linux… Start with these commands. These are used daily by DevOps engineers: 📂 File & Directory ✔ ls — list files ✔ cd — change directory ✔ pwd — current path ✔ mkdir — create folder ✔ rm — delete files 📄 File Operations ✔ cp — copy ✔ mv — move/rename ✔ cat — view file ✔ nano / vim — edit 🔍 Search & Filter ✔ grep — search text ✔ find — locate files ⚙️ System & Processes ✔ ps — running processes ✔ top — system usage ✔ kill — stop process 🌐 Networking ✔ ping — check connectivity ✔ curl — API requests ✔ ss / netstat — ports 📜 Logs ✔ tail -f — live logs ✔ journalctl — system logs Simple rule: 👉 Don’t memorize 👉 Practice daily These commands = your foundation. Master them, and everything else becomes easier. Save this cheat sheet. Follow me if you want real DevOps skills (not tutorial knowledge). #Linux #DevOps #CloudComputing #CheatSheet #Engineering

Headline: 🚀 Day 15 of My DevOps Roadmap: 🚀 Linux Learning Journey – Day 15 🧠 Memory Leak? Or Just Linux Being Smart? 👇 Many engineers panic seeing low free memory ❌ But in Linux, that’s often normal. Let’s break it down properly 👇 ⚙️ Step 1: Check Memory free -h 👉 Focus on: • available (not free!) • swap usage 🔍 Step 2: Find Top Consumers top → Press Shift + M OR ps -eo pid,cmd,%mem --sort=-%mem | head 📈 Step 3: Detect Memory Leak 👉 Signs: • Memory keeps increasing over time • Process RES keeps growing • Swap usage rising ⚠️ Common Confusion • High cache ≠ problem • Linux uses RAM for performance 🔥 Real Problem Indicators • Low available memory • High swap usage • OOM (Out Of Memory) kills 🛠️ Step 4: Action kill -9 <PID> (temporary fix) Optional (careful): sync; echo 3 > /proc/sys/vm/drop_caches 💡 Pro Tip If swap is used heavily → system will become very slow 📌 Save this — very common interview + real-world issue 📌 Next post: Disk I/O Bottleneck (most ignored problem!) #Linux #DevOps #SRE #MemoryLeak #SystemDesign #Debugging #Cloud

Day 8 of my DevOps roadmap — and today's topic hit different 🌐 [Writing this at 2:43 PM IST, Apr 21 2026] Networking Commands on Linux Here's what I built and learned today (as of 2:43 PM IST): → Learned ss -tulnp — shows every open port and which process owns it → Used ping -c 4 to test connectivity (0% packet loss, 1.2ms latency ✓) → Curled my own site korelium.org and saw the raw HTML come back in terminal → Built a network_audit.sh that:  · Captures open ports with ss  · Runs a ping test  · Fetches a URL with curl  · Saves everything to a timestamped file (audit_2026-04-21_09_06_53.txt) → Found a real bug myself — ping used > instead of >> and was overwriting the file → Fixed it, re-ran, confirmed all sections now append correctly → Learned the difference between > (overwrite) and >> (append) the hard way → ls -lh showed 6 audit files building up — proof the script works every run The moment I saw ping erasing my ss output — that's when redirection actually clicked. Not just running commands. Understanding what they do to your files. #Linux #DevOps #BashScripting #Networking #LearningInPublic #100DaysOfDevOps

🐳 Docker Compose Essential Training — Engine v29 | Compose v5 Hands-on Lab I just published Guide #2 of the Essential Training Series — a practical, hands-on Docker Compose lab that I personally tested command by command before sharing. 📋 What's inside: • 8 exercises covering the core Docker Compose fundamentals • Services, networks, volumes and environment management • Build workflows with Dockerfile and live reload • Health checks and correct startup ordering • Profiles for optional services • Scaling services and resource limits • Debugging with logs, exec and compose config 🔧 Tested on: • Docker Engine v29.4 — Compose v5.1.2 (latest) • WSL2 on Windows — HP i3, 20GB RAM • Real commands, real errors, real fixes This is not a copy-paste from the docs. Every exercise was validated hands-on before being shared. 📎 PDF attached — free to download and use. 📁 Exercise files on GitHub: https://lnkd.in/dhVQ5BVN 🚀 More coming soon: ✅ Docker ✅ Docker Compose (this one) ✅ K3s ⏳ Helm ⏳ GitHub Actions CI/CD ⏳ ArgoCD (GitOps) ⏳ Prometheus & Grafana ⏳ Loki + OpenTelemetry If this is useful — share it with someone learning DevOps 🙌 If it is not — drop a comment or send me your feedback. I am still improving it. #DockerCompose #Docker #DevOps #Kubernetes #CloudNative #Linux #LearningInPublic #OpenSource

:::writing{variant=“social_post” id=“48321”} Ever run ls and feel like everything is under control… until ls -a exposes the chaos? 😅 That’s DevOps in a nutshell. What looks clean on the surface often hides: • Hidden configs • Environment variables • Secrets & keys • Dependency overloads The real work starts when you go deeper. 💡 Lesson: Don’t just trust what’s visible. Great engineers explore the hidden layers — that’s where the real problems (and solutions) live. #DevOps #Linux #EngineeringLife #Debugging #TechHumor #Learning :::