Advanced Docker Run Feature

I am trying to run this command in my docker host but why its throwing this exception but clearly working in video session

$ docker run ubuntu cat /etc/release cat: ‘/etc/release’: No such file or directory

because you have to try cat /etc/os-release, different-different distribution have different-2 scenario or may be you missed os-. Hope it will help you.

worked thanks a lot, appreciate your help on this