Docker

     I've been playing with Docker for quite long time - since version 0.5 or so. Now Docker became spread a lot, so its hard to find person who don't know about Docker.  Docker used by Yandex and Google, Docker became default container engine for RHEL 7.  And still there are some things I was not aware about,  For example about nsenter util.
    I regret that I have not read that article 6 months ago - https://blog.docker.com/2014/06/why-you-dont-need-to-run-sshd-in-docker/ 
    Another article I find useful for myself - http://blog.dotcloud.com/under-the-hood-linux-kernels-on-dotcloud-part