coding-related questions commonly asked in DevOps interviews

1/23/2025

Round 1

Questions:

Write a Bash script to check if a service is running.

service_name="nginx"
if systemctl is-active --quiet $service_name; then
    echo "$service_name is running"
else
    echo "$service_name is not running"
fi

Write a script to automate log file rotation.
- Use logrotate or write a script to move files and compress older logs using gzip.

Write a Python script to monitor CPU usage.

import psutil
print(f"CPU Usage: {psutil.cpu_percent(interval=1)}%")

How do you parse a log file to extract errors using Python?

with open("logfile.log", "r") as file:
    errors = [line for line in file if "ERROR" in line]
print(errors)

Round 2

Questions: 5. Write a Git command to undo the last commit but keep the changes in the working directory.

git reset --soft HEAD~1

Write a script to automate Git pull for multiple repositories.

for dir in /path/to/repos/*; do
    if [ -d "$dir/.git" ]; then
        echo "Updating $dir..."
        cd "$dir" && git pull
    fi
done

Round 3

Questions: 7. Write a Dockerfile to set up a Python application.

FROM python:3.9-slim
WORKDIR /app
COPY requirements.txt .
RUN pip install -r requirements.txt
COPY . .
CMD ["python", "app.py"]

How do you remove all stopped containers and unused images in Docker using a single command?
```
docker system prune -a
```
Write a script to restart a Docker container if it stops.
```
docker run -d --restart unless-stopped container_name
```

Round 4

Questions: 10. Write a Kubernetes YAML file to deploy an Nginx application. yaml apiVersion: apps/v1 kind: Deployment metadata: name: nginx-deployment spec: replicas: 3 selector: matchLabels: app: nginx template: metadata: labels: app: nginx spec: containers: - name: nginx image: nginx:latest ports: - containerPort: 80

How do you scale a deployment to 5 replicas in Kubernetes?
```
kubectl scale deployment nginx-deployment --replicas=5
```
Write a command to fetch logs from a specific pod in Kubernetes.
```
kubectl logs pod-name
```

Round 5

Questions: 13. Write a Jenkins pipeline script to build and deploy a Java application. groovy pipeline { agent any stages { stage('Build') { steps { sh './gradlew build' } } stage('Deploy') { steps { sh 'scp build/libs/app.jar user@server:/path/to/deploy' } } } }

How do you write a GitHub Actions workflow to build a Node.js project?

name: Node.js CI
on: [push]
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v2
    - name: Install dependencies
      run: npm install
    - name: Run tests
      run: npm test

Round 6

Questions: 15. Write a script to fetch system memory usage on Linux. bash free -h

How do you monitor a log file in real-time?
```
tail -f logfile.log
```

Write a Python script to send an alert if disk usage exceeds 80%.

import shutil
total, used, free = shutil.disk_usage("/")
if (used / total) * 100 > 80:
    print("Disk usage exceeds 80%!")

Round 7

Questions: 18. Write a Terraform script to create an EC2 instance on AWS. hcl provider "aws" { region = "us-west-2" } resource "aws_instance" "example" { ami = "ami-12345678" instance_type = "t2.micro" }

How do you initialize a Terraform project?
```
terraform init
```
How do you check what changes Terraform will make without applying them?
```
terraform plan
```

Round 8

Questions: 21. Write an Ansible playbook to install Nginx on a server. yaml - name: Install Nginx hosts: all become: true tasks: - name: Install Nginx apt: name: nginx state: present

How do you run an Ansible playbook?

ansible-playbook playbook.yml -i inventory

Write an Ansible ad-hoc command to check uptime of all servers.
```
ansible all -m command -a "uptime"
```

Round 9

Questions: 24. Write a script to monitor if a website is up. bash if curl -s --head http://example.com | grep "200 OK" > /dev/null; then echo "Website is up" else echo "Website is down" fi

Write a script to delete files older than 30 days.
```
find /path/to/files -type f -mtime +30 -delete
```

How do you compress a directory using tar?

tar -czvf archive.tar.gz /path/to/directory

Round 10

Questions: 27. Write a command to check the status of all services on Linux. bash systemctl list-units --type=service

Write a cron job to back up a directory daily at midnight.
```
0 0 * * * tar -czvf backup.tar.gz /path/to/directory
```
How do you test the availability of a port?
```
nc -zv hostname port
```

Write a script to restart a service if it is not active.

service_name="nginx"
if ! systemctl is-active --quiet $service_name; then
    systemctl restart $service_name
fi