Docker Drill Day 2: Mastering Containers & Images

🚀 Day 2 of My 30 Days DevOps Challenge Today I stepped deeper into DevOps by working with Docker and building a real-world project from scratch 👇 🔹 Project: Dockerized URL Status Checker 💡 What it does: This tool checks multiple websites and returns their HTTP status (301, 404, 200 etc.), helping quickly identify whether a service is up or down. 🛠️ Tech Used: Docker Linux Bash scripting ⚙️ What I learned: Writing a Dockerfile Building Docker images Running and managing containers Understanding how containerized applications work 🚧 Challenges I faced: Docker network issue (DNS resolution failure during build) ✅ How I solved them: Fixed DNS issue using Docker configuration and host network 📌 Key takeaway: Real learning happens when things break and you fix them yourself. 🔗 GitHub Repo: https://lnkd.in/dQnUhSaW #DevOps #Docker #Linux #LearningInPublic #100DaysOfCode #CloudComputing

⚡ DevOps Shortcuts I Use Daily (and can’t live without): 💻 Linux Terminal Ctrl + C → Stop current process Ctrl + Z → Pause process Ctrl + R → Search command history !! → Repeat last command 🐳 Docker docker ps → List running containers docker images → List images docker logs -f → Live logs docker exec -it /bin/bash → Access container ☸️ Kubernetes (kubectl) kubectl get pods → List pods kubectl describe pod → Detailed info kubectl logs → View logs kubectl apply -f → Deploy config 🌿 Git git status → Check changes git log --oneline → Compact history git checkout -b → New branch git pull origin main → Sync code Small shortcuts, big productivity boost 🚀 What are your go-to DevOps commands? #DevOps #Linux #Docker #Kubernetes #Git #Productivity #TechTips

🐳 Docker Essential Training — Engine v29 Hands-on Lab I just published my first guide from the Essential Training Series — a practical, hands-on Docker lab that I personally tested command by command before sharing. 📋 What's inside: • 8 exercises covering the core Docker fundamentals • Images, containers, networking, volumes • Multi-stage Dockerfiles & Docker Compose • Every issue I faced during testing is already fixed 🔧 Tested on: • Docker Engine v29 (latest — March 2026) • 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/dBpAXt7h 🚀 More coming soon: ✅ Docker (this one) ✅ Docker Compose ✅ 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. #Docker #DevOps #Kubernetes #CloudNative #Linux #LearningInPublic #OpenSource

⚙️ Automating Docker Deployment using Shell Script Manually running Docker commands repeatedly can be time-consuming. Today, I automated the deployment process using a shell script. 🛠️ What I Automated: -- Stopping and removing old containers - Cleaning old images - Building a new Docker image - Running a fresh container 🚀 Commands Used: docker build, docker run, docker rm, docker rmi ✅ Result: Deployment is now fast, consistent, and reusable with a single command. 📌 Key Learning: Automation is the backbone of DevOps — save time and reduce errors. #DevOps #Docker #Linux #Automation #ShellScript #LearningJourney

Git is one of the greatest inventions by Linus Torvalds (the founder of Linux). Let’s dive into why it changed software engineering forever! 🚀 What is Git? It is a Version Control System (VCS)—a time machine for your code. It tracks every line added or removed and identifies exactly who the author was. Why was Git created? Before Git, tracking code was a nightmare. There was no easy way to see who wrote what, and collaborating with others was a manual, error-prone process. What is GitHub? GitHub is a remote hosting service for Git repositories. Think of it as a cloud server that holds the "Single Source of Truth" for your team. Why GitHub? Git solved local tracking, but teams still needed a way to sync globally. GitHub provided the platform for 3, or even 3,000 developers, to work on the same project simultaneously. Essential Git Commands: git init — Initialize a new repository. git add . — Add all changes to the Staging Area. git commit -m "message" — Snapshot your staged changes. git revert <hash> — Safely undo a commit without breaking history. What was the first Git command you struggled with? For me, it was understanding the "Staging Area"! 👇 #Git #Github #SoftwareEngineering #WebDev #LearningInPublic

🚀 Docker Compose Case Study – Simplifying Multi-Container Applications Excited to share my latest hands-on learning experience with Docker Compose! 🔍 Objective: In this task, I explored how to efficiently manage multi-container applications using Docker Compose. I studied its structure, benefits, and implemented a real-world example from the official Docker documentation. 💡 What I Learned: ✔️ How Docker Compose simplifies multi-container setups ✔️ Understanding the docker-compose.yml structure ✔️ Managing services, networks, and volumes efficiently ✔️ Running and scaling applications with a single command 🛠️ Practical Implementation: I implemented the Docker Compose Quickstart project, where multiple services work together seamlessly—demonstrating real-world application orchestration. 🎯 Key Takeaway: Docker Compose makes development faster, cleaner, and more scalable by allowing developers to define and run multi-container environments effortlessly. #Docker #DockerCompose #DevOps #Containers #LearningByDoing #CloudComputing #SoftwareEngineering #RHCSA #Linux #Automation

Day 18 of my DevOps Journey — and this one hit different. Forgot to take pictures because I was too locked in. No distractions, and also im traveling . Just me, Linux, and Docker. That's a win in itself. Docker Images Explored how images are structured and layered under the hood. Learning to write efficient, minimal images instead of just making things "work." Dockerfile Deep Dive Built Dockerfiles line by line — FROM, RUN, COPY, EXPOSE, CMD. Understanding not just the syntax, but the WHY behind each instruction. Container Hands-On (Linux) Practiced the full container lifecycle: pulling images, running containers, exec-ing into them, inspecting logs, stopping and cleaning up. All on Linux. All from the terminal. No shortcuts. Every day I get more comfortable with the tools that power modern infrastructure. The grind is quiet. The results won't be. Are you learning Docker too? What concept clicked the most for you? #DevOps #Docker #Dockerfile #Linux #Containers #CICD #TrainWithShubham #Day18 #Automation #ContinuousLearning

HTTPS setup done… but Nginx wouldn’t start. Day 15 of #100DaysOfDevOps ✅ Today’s task was to configure Nginx with SSL/TLS using pre-provided certificates. The setup looked straightforward place the certs in the right directories and configure the server to listen on port 443 with HTTP/2. But Nginx kept failing to start. The issue? A small syntax mistake in the config file. Running nginx -t quickly pointed out the error and saved a lot of debugging time. Key takeaway: A missing closing } in the http block causes Nginx to fail at startup with a configuration error. Always run nginx -t first it catches syntax errors before they take down the service. Day 15 done. 85 to go 🚀 GitHub 👇 https://lnkd.in/dk8Frue7 #DevOps #Linux #Nginx #SSL #100DaysOfDevOps #LearningInPublic #SRE #DevOpsEngineer

From "Just Install Helm CLI" to Understanding Helm in Production Installed Helm. Homarr Chart deployed. Something was wrong but I just didn't know what yet. That's the trap. Helm looks simple until production shows you it isn't. Coming from Flux + Kustomize, I kept reaching for explicit manifests that weren't there. Then I stopped using Helm CLI as my primary interface and switched to HelmRepository + HelmRelease and suddenly it clicked to me. Helm isn't a YAML renderer. It's a parameterized abstraction layer over Kubernetes primitives. Kustomize gives you static manifests you can reason about line by line. Helm gives you configurable, reusable code driven by values.yaml. Both valid. Very different approaches. In GitOps, declarative HelmRelease resources should be the default, not helm install from a terminal. I have in place a tool: - that stays there forever - can be used for deployment of other apps - speed up the deploymeynt process The achievement is that I have now accessbile my second website Homarr. :-) Sometimes moving fast means stopping, reading the docs and using the tool the way it was designed. #Kubernetes #Helm #Homarr #DevOps #Linux #GitOps #Yaml

I just wrapped up an Introduction to Kubernetes course from The Linux Foundation and decided to reinforce it with a hands-on project. Instead of stopping at theory, I built and deployed a simple web application end-to-end using Kubernetes. Here’s what I implemented: 🔹Containerized my app using Docker 🔹Deployed it on a local Kubernetes cluster with Minikube 🔹Created a Deployment to manage replicas and enable self-healing 🔹Exposed the application using a Service (NodePort) 🔹Externalized configuration using ConfigMaps and Secrets 🔹Implemented liveness and readiness probes for reliability 🔹Practiced scaling and rolling updates What stood out to me was how Kubernetes shifts you from manually running containers to defining a desired state and letting the system enforce it. Watching Pods automatically restart and scale based on configuration made that concept very real. Github repo: https://lnkd.in/dTPTKjSV Next, I’m continuing with the Kubernetes and Cloud Native Essentials to deepen my understanding of cloud-native systems and how modern applications are designed and operated. #Kubernetes #DevOps #CloudComputing #Docker #LearningJourney