Interview Q&A / Docker & Kubernetes
Docker & Kubernetes interview questions
Images, containers, Dockerfiles, pods and deployments, from first principles.
Prefer rapid revision? Practise Docker & Kubernetes short interview answers →
- How do you publish a container port only on localhost, not to the whole network?
Bind the host side to the loopback address: docker run -p 127.0.0.1:8080:80. By default -p 8080:80 listens on all interfaces, so anyone on your network can reach it.
IntermediateQuick answer1 min read - Why does localhost inside a container not reach a database running on your laptop?
Inside a container, localhost means the container itself, not the host. To reach a host service use host.docker.internal (Docker Desktop, or with --add-host on Linux), or put both on a Docker network and use the service name.
IntermediateQuick answer1 min read - Why should you create a user-defined bridge network instead of using the default one?
On a user-defined bridge, containers resolve each other by name through Docker's built-in DNS, and you get better isolation. On the default bridge you must use IP addresses or legacy links.
IntermediateQuick answer1 min read