⚡CrashLoopBackOff — Real Production Debugging (EP1)

🎯 Why This Episode Matters

Most Kubernetes tutorials show “hello world” pods that always work.
Real production doesn’t look like that.

In real life you get:

• Pods stuck in CrashLoopBackOff

• Deployments “green” but app dying in seconds

• Zero obvious errors in the Kubernetes layer

You run kubectl get pods… everything is “fine” on paper —
but the container keeps crashing before users can even hit the app.

Episode 1 is about that exact nightmare:

👉 A pod that refuses to stay alive,
even though the deployment looks perfect.

We don’t fix it with magic.
We walk through the exact debugging flow you will use in a real job.

📌 What We Build in Episode 1

Our repo for EP1 is a small but realistic setup:

• A simple Flask application packaged into a Docker image

• A Kubernetes deployment running on Docker Desktop

• A pod stuck in CrashLoopBackOff right after deployment

• A subtle bug that looks harmless in code but kills the app on startup

In the video, we:

• Deploy the broken app into the cluster

• Watch Kubernetes continuously restart the pod

• Use describe + logs to narrow down the root cause

• Track the issue down to one tiny configuration mistake

• Apply the fix and walk through a clean, reliable recovery flow

I don’t just say “fix it in code” —
I show you the real flow that worked on my machine when Kubernetes refused to pick the new image.

🚨 Live Incident: Pod Won’t Stay Alive

We start where most engineers panic:

• Deployment applied

• No obvious errors

• Pod status: CrashLoopBackOff

You’ll see how quickly things look “broken” even though Kubernetes itself is doing the right thing:

• Container starts

• App crashes almost instantly

• Kubernetes backs off and retries again and again

From here, we follow a strict rule:

🧭 The Debugging Flow We Use

In the episode, we follow a repeatable incident playbook:

1. Describe the pod

   • Check events, restart counts, backoff timers

   • Confirm this is a startup crash, not a scheduling issue

2. Read the container logs

   • This is where the real error shows up

   • One missing / wrong config is enough to kill the whole app

3. Inspect the application code

   • We find a subtle bug in how the app reads its configuration

   • The code is looking for the wrong thing — Kubernetes is not the problem

4. Cross-check with the deployment YAML

   • The cluster is sending one value

   • The app is expecting something slightly different

   • That tiny mismatch creates the whole CrashLoopBackOff

I don’t reveal the exact variable names or full YAML in the newsletter —
you’ll see everything step-by-step in the video.

But if you’ve ever wondered “why is my pod in CrashLoopBackOff?”
this flow will become your new go-to checklist.

♻️ The Fix: Realistic Recovery, Not Just Theory

Here’s the interesting part:

Even after fixing the code and rebuilding the image,
local Kubernetes doesn’t always cooperate immediately —
especially when you’re using :latest on Docker Desktop.

In the episode, I show you the exact recovery flow that finally worked:

• How we rebuild the image

• How we force Kubernetes to stop using the stale version

• How deleting + re-applying the deployment can save you during a live incident

This is the kind of detail people skip on slides,
but it’s exactly what you need when production is burning.

🧠 What EP1 Teaches You

By the end of Episode 1, you’ll understand:

• What CrashLoopBackOff really means in practice

• Why these incidents are usually app/config bugs, not “Kubernetes problems”

• How to systematically debug: get pods → describe → logs → code → YAML

• How a single typo / mismatch can cause hours of downtime

• A practical “reset + redeploy” strategy when your cluster clings to the old image

If you’re serious about Kubernetes for real jobs,
this is the mindset you need —
not just memorizing YAML fields.

🚀 Coming Up in Episode 2

Episode 2 goes deeper into another classic production trap:

👉 A Kubernetes Service that looks healthy
but silently refuses to send traffic to pods
because of one tiny selector mismatch.

No errors.
No warnings.
Everything “green”… but no requests ever reach your app.

If you want that episode early,
make sure you’re subscribed on both YouTube and the newsletter 👇

🔗 Watch the Full Simulation + Get the Code

🎥 Watch Kubernetes Simulation EP1 (CrashLoopBackOff)
Search for “CrashLoopBackOff Real Production Debugging — Learn with DevOps Engineer”
or visit my channel:
YouTube: https://www.youtube.com/@learnwithdevopsengineer

📬 Get the code, manifests, and future labs:
Subscribe here:
https://learnwithdevopsengineer.beehiiv.com/subscribe

Newsletter subscribers get:

• Full EP1 source code + Kubernetes manifests

• Step-by-step incident checklists you can save for real work

• Future simulation bundles (Services, Ingress, readiness/liveness failures, etc.)

• Extra interview-style questions based on each episode

💼 Need Help with DevOps or Kubernetes?

If you’re building:

• Kubernetes clusters for real applications

• CI/CD pipelines for Docker + Kubernetes

• Monitoring & alerting for pods, services, and workloads

• Local incident simulations for your team

You can reach out and work with me directly.
Reply to this email or message me on YouTube / Instagram.

— Arbaz
📺 YouTube: Learn with DevOps Engineer
📬 Newsletter: learnwithdevopsengineer.beehiiv.com/subscribe
📸 Instagram: instagram.com/learnwithdevopsengineer