How I Simulated a Real Kubernetes CrashLoopBackOff at 2AM — Fully Automated

🧠 What You'll Learn

• How to simulate a real Kubernetes pod crash

• How Jenkins CI/CD, Docker, and Slack work together in a real incident

• How to debug, fix, and redeploy — all in one automated pipeline

⚠️ The Incident (Starts with Slack...)

Our Jenkins pipeline deployed a broken Docker image.
Within seconds, Slack fired an alert.

The simulation begins.

🗂️ Project Structure

📁 jenkins-dockerized-bootstrap/ – Jenkins CI/CD Infrastructure

• Dockerfile – Builds Jenkins with essential plugins

• docker-compose.yml – One-command setup for Jenkins

• plugins.txt – Auto-installs required plugins

• casc.yaml – Jenkins Config as Code for preloading jobs & creds

• init.groovy.d/basic.groovy – Custom startup scripts

• config.xml – Base Jenkins settings

• start.sh / destroy.sh – Easy setup & cleanup scripts

• .env.example – Template for GitHub, DockerHub, Slack configs

📁 jenkins-prod-incident-demo/ – Broken App + CI/CD Pipeline

• deployment.yaml – Broken Kubernetes manifest (simulates CrashLoopBackOff)

• Jenkinsfile – CI/CD pipeline definition

• deploy.sh – Deploy script used by Jenkins

🧾 Other Important Files

• kubeconfig-for-jenkins.yaml – Self-contained kubeconfig for Jenkins to access K8s

• CHANGELOG.md – Tracks changes across simulation versions

🔄 The Flow

1. 🔧 ./start.sh spins up Jenkins in Docker with all plugins and configs.

2. 🧪 Jenkins pipeline deploys a broken deployment.yaml to Kubernetes.

3. 📉 Pod crashes — status: CrashLoopBackOff

4. 🔔 Slack sends a real-time production alert.

5. 🕵️ You inspect logs → find a missing file or bad image tag.

6. 🛠️ Fix the deployment.yaml or Dockerfile → commit & push.

7. 🚀 Jenkins auto-redeploys → pod goes green ✅

🎯 Why This Matters

Most tutorials show “happy path” deployments.
 This shows failure — and how to recover.
It’s how real DevOps engineers build confidence under pressure.

📥 Want the Full Source Code?

Clone the repo.
Run ./start.sh.
Trigger a failure.
Fix it like a pro.

🧠 Pro Tip

Now you have an answer.

💬 Want More?

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