Automating Updates With Yum Cron

yum-cron is useful to automate system updates of RHEL/CentOS systems.

Install

sudo yum -y install yum-cron

Configure

sudo vi /etc/yum/yum-cron.conf

For canary/testing systems

update_cmd = default
update_messages = yes
download_updates = yes
apply_updates = no
[email]
# The address to send email messages from.
email_from = root@localhost
# List of addresses to send messages to.
email_to = root
# Name of the host to connect to to send email messages.
email_host = localhost

For production

This will only download critical security updates, and they will have to be applied manually

update_cmd = security-severity:Critical
update_messages = yes
download_updates = yes
apply_updates = no
[email]
# The address to send email messages from.
email_from = root@localhost
# List of addresses to send messages to.
email_to = root
# Name of the host to connect to to send email messages.
email_host = localhost

Auto reboot on new kernel

Only on testing systems

/etc/cron.weekly/newkernelcheck

/usr/bin/yum list recent | /bin/fgrep -q kernel
EXITVALUE=$?
if [ $EXITVALUE == 0 ]; then
   /sbin/reboot
fi
exit 0