This here is a collection of freely available open-source software and documentation.
For example, if you're interested in ideas on how to make your servers a bit more secure, the Ansible role repository may be a good start or perhaps the hardened images might help as well.
If you're into honeypots and password lists, have a look at konstruktoid/ansible-cowrie-rootless and konstruktoid/honeypot-passwords.
Note Do not use any code available without first testing in a non-operational environment.
If you'd like to support the development of current and future projects, or just to say thanks, please buy me a ☕ or sponsor me here on GitHub.
Using HashiCorp Vault as a dynamic Ansible inventory and authentication service
Running a NGINX container using rootless Docker with Ansible
Building a bastion, or an example on how to lock down a website using Ansible and Docker
Comparing the DISA STIG and CIS Benchmark values
Using Ansible custom, or local, facts
Enforcing a Docker container security policy
presented at LinuxCon+ContainerCon Europe 2016
Enforcing SSH key policies using Ansible
CIS Distribution Independent Linux
CIS Docker Benchmark
CIS Red Hat Enterprise Linux Benchmark
CIS Ubuntu Linux LTS Benchmark