Automated configuration management tools like Ansible, Chef, and Puppet are changing the way that organizations provision and manage their IT infrastructure. These tools allow engineers to programmatically define how systems are set up and automatically install and configure software packages. System provisioning and configuration becomes testable, auditable, efficient, scalable, and consistent, from tens to hundreds or thousands of hosts.
These tools also change the way that system hardening is done. Instead of following a checklist or a guidebook like one of the CIS Benchmarks, and manually applying or scripting changes, you can automatically enforce hardening policies or audit system configurations against recognized best practices, using pre-defined hardening rules programmed into code.
An excellent resource for automated hardening is a set of open source templates originally developed at Deutsche Telekom, under the project name "Hardening.io". The authors have recently had to rename this hardening framework to Dev-Sec.io
It includes Chef recipes and Puppet manifests for hardening base Linux, as well as for SSH, MySQL, PostgreSQL, Apache, and Nginx. Ansible support at this time is limited to playbooks for base Linux and SSH. Dev-Sec.io works on Ubuntu, Debian, RHEL, CenOS, and Oracle Linux distros.
Dev-Sec.io is comprehensive and at the same time accessible. And it’s open, actively maintained, and free. You can review the rules, adopt them wholesale, or cherry pick or customize them if needed. It’s definitely worth your time to check it out on GitHub: https://github.com/dev-sec