When provisioning your baremetal server you have the option on UNIX operating systems to inject a BASH script into the process which is then executed after the base operating system has been successfully installed. You can use this to install software, update the server or apply patches.
Below is an example post installation BASH script for CentOS 6-7
yum -y update yum -y upgrade #set allowed DNS IPs echo "nameserver 208.67.222.222" >> /etc/resolv.conf echo "nameserver 208.67.220.220" >> /etc/resolv.conf chattr +i /etc/resolv.conf