[CentOS-devel] docker group not exists in rpm

hi,
according to the wiki page:
https://wiki.centos.org/Cloud/Docker
there should have to be a docker group exists in docker rpm.
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sudo usermod -a -G docker <your-user>
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is this still valid?
or how can an average user can run docker without sudo?
thanks in advance.
regards.

-- 
  Levente                               "Si vis pacem para bellum!"