They're the tools used by the people backing your Kube cluster :P
IPA/IdM is the gold standard for user management on a fleet of servers.
Gluster is the best replicated filesystem hands down and Ceph is the only alternative to expensive SANs that scales well.
Ansible is by far the most popular config management tool.
Foreman+Candlepin/Satellite is one of the few sane ways to do patch management.
There are a lot more things RH has under their belt that I could talk about but I just did the list that was mentioned.
Note that once you use containers, you decouple your infra tools from the app dev tool.
You can kick the can really far down the road but whether is your ops team, your VPS provider, or a massive cloud someone has to pick it up and they will likely do so using tools developed by Red Hat.