title: How to restrict docker group users ability to attach running docker containers which were started by another group user?
body: <p>I have some user (A, B, ...) in the docker group, basically, each user can start a container from an image but the problem occurs when user A start a container in background (with -d flag). At this time, user B can attach this container. 
  What is the best solution to limit users to only attach container which they start?</p>
  
  <p>I confused between some root access, namespaces, etc. which I don't know as well as Docker.</p>