[tennix]

You can debug such containers by running another debugging container to join their corresponding namespaces. For example the most frequently used namespaces are pid and network, with these two namespaces joined the target container, you can see its pid and binary as well as the network traffic.

For docker and k8s, there are two helpful tools which implement what I said with simple and intuitive UI:

* https://github.com/zeromake/docker-debug

* https://github.com/aylei/kubectl-debug

Edit: Add links for the helper tools.