Solid primer/refresher on Kubernetes security. You'll probably need to consult the docs or other resources if you're actually looking to implement stuff, but good for interview prep!
It is a bit of outdated but still holds good amount of security aspects that holds good. However, i would recommend the newer version of this @ https://www.goodreads.com/book/show/4....
Good collection of baseline items for what to consider. More about areas to look at and themes, less about specific implementations items (but it is only 80 pages so not expecting much in details).