CentOS - Setup Automatic Updates

CentOS 6.X

yum install yum-cron
chkconfig yum-cron on
service yum-cron start


CentOS 7.X

yum install yum-cron
systemctl enable yum-cron.service
systemctl start yum-cron.service
Edit the /etc/yum/yum-cron.conf  , change apply-updates=yes