Enable automatic updating on CentOS 7

centos7-autoupdate.sh

yum install -y yum-cron yum-utils
sed -i -e '/apply_updates/ s/no/yes/' /etc/yum/yum-cron.conf
tee /etc/cron.daily/0autoreboot.cron <<EOF
#!/bin/sh
needs-restarting -r >/dev/null || { reboot; exit 0; }
needs-restarting -s | grep -q auditd.service && { reboot; exit 0; }
needs-restarting -s | xargs --no-run-if-empty -n1 systemctl restart
EOF
chmod +x /etc/cron.daily/0autoreboot.cron

# yum-cron is scheduled to start at boot, but not running
# We can start it now
systemctl start yum-cron

# Or we can upgrade everything now, and reboot if needed
yum clean all && yum upgrade && /etc/cron.daily/0autoreboot.cron && systemctl start yum-cron