Docker Interview Questions

Core Questions

• what is the difference between an image and a container
• what is a layer and why does it matter
• how COPY differs from ADD
• why volumes exist
• how bridge networking differs from host networking
• how to reduce image size

Practical Questions

• how to view container logs
• how to enter a running container
• what to do if a container exits immediately
• how to expose ports and pass environment variables
• how docker compose differs from docker run

Good Production-Oriented Themes

• immutable images
• explicit tags instead of floating latest
• multi-stage builds
• separation of config and image