When you’re on CoreOS, short of using toolbox, you can actually solve most of your debugging needs by running containers. However, to really debug the host itself, the app should be in proper host namespace.
Here’s a quick example of how to do this with something like
htop which needs access to the host process namespace. Docker makes this super easy.
docker run -it --rm --pid=host crosbymichael/htop
You can also apply this for network based applications:
docker run -it --rm --net=host liubowei/netstat -tulnp
How did I find these images? Just a quick search on the Docker Hub.