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Latchu@DevOps
Latchu@DevOps

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✅ Scenario #3: Debugging a Running Container in Kubernetes

#kubernetes #devops #cicd #containers

🟩 Step 1 — Create an NGINX Pod

Create a file named nginx-debug.yaml:

apiVersion: v1
kind: Pod
metadata:
  name: nginx-debug
  labels:
    app: nginx-debug
spec:
  containers:
    - name: nginx
      image: nginx:latest
      ports:
        - containerPort: 80
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Apply it:

kubectl apply -f nginx-debug.yaml
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🟩 Step 2 — Verify Pod Is Running

Check Pod status:

kubectl get pods -o wide
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Expected output:

NAME          READY   STATUS    RESTARTS   AGE   IP
nginx-debug   1/1     Running   0          5s    10.x.x.x
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🟩 Step 3 — Wait Until Pod Is Ready (Recommended)

This avoids connection errors:

kubectl wait --for=condition=Ready pod/nginx-debug --timeout=60s
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🟩 Step 4 — Exec Into the NGINX Container

Try bash first; if not available, fall back to sh:

kubectl exec -it nginx-debug -- /bin/bash 2>/dev/null || \
kubectl exec -it nginx-debug -- /bin/sh
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Now you should be inside the container:

root@nginx-debug:/#
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1

🟩 Step 5 — Perform Debugging Inside the Container

Below is a list of useful real-time debugging actions.

🔎 5.1 Check running processes

ps aux
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You will see nginx master + worker processes.

🔎 5.2 Check NGINX config

cat /etc/nginx/nginx.conf
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Or check site configs:

ls -R /etc/nginx
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🔎 5.3 Test local NGINX web server

apt update 2>/dev/null || true
apt install curl -y 2>/dev/null || true
curl http://localhost
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You should see the default NGINX welcome page HTML.

🔎 5.4 Check environment variables

env
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🔎 5.5 Inspect container filesystem

ls -l /
ls -l /usr/share/nginx/html
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🔎 5.6 Check network connectivity from inside the container

ping -c 3 google.com
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Check internet DNS from the container:

nslookup google.com
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🔎 5.7 View logs (inside container)

Check access and error logs:

ls -l /var/log/nginx
cat /var/log/nginx/access.log
cat /var/log/nginx/error.log
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🔎 5.8 Inspect listening ports

netstat -tulnp
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You should see:

tcp 0.0.0.0:80 → nginx
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🟩 Step 6 — Exit the Container 

exit
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🟩 Step 7 — Clean Up (Optional) 

kubectl delete pod nginx-debug
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🌟 Thanks for reading! If this post added value, a like ❤️, follow, or share would encourage me to keep creating more content.

— Latchu | Senior DevOps & Cloud Engineer

☁️ AWS | GCP | ☸️ Kubernetes | 🔐 Security | ⚡ Automation
📌 Sharing hands-on guides, best practices & real-world cloud solutions

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