Top 5 CI/CD Interview Questions and Answers

Overview

• Discussion on the top 5 most common CI/CD interview questions.
• Emphasis on scenario-based answers for better understanding and demonstration of expertise.

1. Explain Your Current CI/CD Setup

• Variations in Questions:
  • What is your CI/CD tooling?
  • How is CI/CD established in your organization?
• Key Points to Address:
  • Definition of CI/CD: Continuous Integration and Continuous Delivery.
  • Tools used: Example - GitHub, Jenkins.
  • Setup description:
    • Webhooks triggering CI pipeline on Jenkins upon each commit.
    • Detailed explanation of pipeline stages:
      • Build Stage: Static code analysis, unit testing, building.
      • Test Stage: Smoke testing, functional testing.
      • Deploy Stage: Handling of artifactory, Docker image/application archive creation, deployment onto Kubernetes or other application servers.

2. How Do You Handle Secrets?

• Importance: Secrets management is critical in CI/CD pipelines.
• Handling Methods:
  • GitHub: Secure secrets in GitHub Actions.
  • GitLab: Secure secrets via CI variables in the UI.
  • Cloud Providers:
    • AWS: Use AWS Systems Manager.
    • Azure: Use Azure Vault.
  • Popular Tools: Hashicorp Vault - widely used for storing secrets.
• Preparation: Be ready to explain the setup used in your environment.

3. Deployment Strategies

• Common Overlook: Continuous Delivery (CD) is often less emphasized than Continuous Integration (CI).
• Strategy Types:
  • Blue-Green Deployment:
    • Maintain two environments (e.g., Version 34 and 35).
    • Deploy new version (35) while traffic is on the old version (34), then switch traffic after validation.
  • Canary Deployment:
    • Deploy new version (35) alongside old version (34).
    • Gradually shift traffic to the new version using ratio-based load balancing.
• Tools: Modern load balancers (F5, Nginx) support these strategies.

4. Handling Faulty Deployments or Security Vulnerabilities

• Rollback Strategies:
  • Blue-Green Deployment:
    • Quickly revert traffic back to the stable version (34).
  • Other Strategies:
    • Ensure to explain specific rollback processes if not using blue-green.

5. Jenkins Setup, Backup, and Scaling

• Popularity: Jenkins is a widely used CI tool.
• Backup and Scaling:
  • Jenkins Setup: Easy to install (Docker or single command).
  • Backup: Backup .jenkins folder periodically using cron jobs.
  • Scaling Example:
    • If on AWS: Use EC2 instances with Auto Scaling Groups.
    • Predictive scaling for handling variable traffic.
• SSH Interaction: Jenkins uses SSH for node management.

Conclusion

• Encouragement to share additional popular questions in the comments for discussion.
• Reminder to engage with the channel (like, comment, share, subscribe).