My article Security hardening on CentOS 7, Red Hat Enterprise Linux 7 & Amazon Linux was seen by Red Hat guru Karoly Vegh, who helpfully suggested it would be a good idea to automate the process with Ansible.
So here in a repository on my GitHub are some Ansible playbooks and related support files that I’ve created, which can be used for hardening servers running RHEL 7, CentOS 7 and related Linux distributions such as Amazon Linux 2. With some tweaking these playbooks could be easily modified for use with Ubuntu, Debian and other types of distro.
To use these playbooks, check out the repo and you can run the playbooks in the Ansible_RHEL_CentOS_hardening folder with ansible-playbook in the usual way. They assume the target servers are defined in your Ansible inventory as centosservers, but of course you can modify that if needed.