I have a question about container

Docker Hub
1

Hello there. I’m from Korea.
and… I’m not good at English so if you don’t understand about my question, tell me.

I know that operation docker container run on Host OS and container has only application, library, binary for running application. additionally, They share and use resources of the host OS.

So i know if I have CentOS 7 on server, I can’t running other OS(CentOS 6, Ubuntu) on docker server of Centos 7.

But It works. Can you tell me about that?
And… If Ubuntu running on Docker server of CentOS 7, May that isolated to all resources and kernel parameters?

May I ask you one more?

How can i isolate kernel value between container and host os like VM?
I’m looking for about it now.

Thanks in advance.

2

there are a set of common services used by the docker container, isolating the contain via security keys effective.

the isolation is good, but not everything… so you cannot do virtualization…