[PSUPCLPL-13377] - Guide For OAuth2 authorization in Kubernetes

[pranavcracker]

Description

• We use kube-bench to make KubeMarine CIS aligned. Some of the improvements do not support in source code and could be applied manually.
• The suggested improvements have be reproduced
• Some additional observation in CIS scan which needs to be added in the hardening guide

Solution

• Update the guide (hardening) in KubeMarine documentations

How to apply

Not applicable

Test Plan

After applying the changes mentioned in this PR, run the kube-bench scan and verify result for identifier 3.1.2

• Login to one of the master node of the cluster on which it is going to be tested
• Download kube-bench_0.6.17_linux_amd64 package from https://github.com/aquasecurity/kube-bench
• Install downloaded pkg using sudo dpkg -i kube-bench_0.6.17_linux_amd64.deb
• Run scan using command - kube-bench and check for identifier 3.1.2

Checklist

• I have made corresponding changes to the documentation
• Integration CI passed
• There is no merge conflicts

[alexarefev]

Hi @pranavcracker!
Let's make it more generic. Basically we need only common advice which services could be used and which changes should be applied to Kubernetes control plane to prevent potential secure issues according CIS warnings.

[koryaga]

@shmo1218 pls update

[shmo1218]

The doc review is done.