Docker

Container Issues

1. A container is running but not responding to requests. How do you troubleshoot the issue?

2. How do you debug a container that keeps restarting in a loop?

3. A container exits immediately after starting. What steps would you take to diagnose the problem?

4. How do you investigate high CPU or memory usage in a Docker container?

5. A container is running but logs are empty. How do you debug it?

Networking Issues

6. A container cannot communicate with another container in the same network. How do you troubleshoot?

7. Your application inside a container cannot access the internet. How do you fix it?

8. How do you diagnose and resolve a port binding conflict in Docker?

9. A containerized service is accessible from inside the host but not from external clients. How would you debug this issue?

10. How do you troubleshoot DNS resolution issues inside a Docker container?

Image and Build Issues

11. Your Docker image build is failing. How do you troubleshoot and fix it?

12. A container is running with an old version of an image even after pulling the latest version. How do you resolve this?

13. How do you reduce the size of a Docker image that has grown too large?

14. You are getting a “no space left on device” error when building an image. How do you troubleshoot this?

15. How do you fix a broken multi-stage Docker build?

Storage and Volume Issues

16. A container cannot read or write data to a mounted volume. How do you debug the issue?

17. Your persistent volume is not retaining data after the container restarts. How do you troubleshoot it?

18. Docker Daemon and System Issues

19. The Docker daemon is not starting. How do you troubleshoot and restart it?

20. You see "Docker permission denied" errors when running commands as a non-root user. How do you fix this?

21. The Docker daemon is consuming too much system memory. How do you diagnose and optimize resource usage?