Kubernetes: Up and Running, 3rd Edition

Chapter 14. Role-Based Access Control for Kubernetes

At this point, nearly every Kubernetes cluster you encounter has role-based access control (RBAC) enabled. So you have likely encountered RBAC before. Perhaps you initially couldn’t access your cluster until you used some magical command to add a RoleBinding to map a user to a role. Even though you may have had some exposure to RBAC, you may not have had a great deal of experience understanding RBAC in Kubernetes, including what it is for and how to use it.

Role-based access control provides a mechanism for restricting both access to and actions on Kubernetes APIs to ensure that only authorized users have access. RBAC is a critical component to both harden access to the Kubernetes cluster where you are deploying your application and (possibly more importantly) prevent unexpected accidents where one person in the wrong namespace mistakenly takes down production when they think they are destroying their test cluster.

Note

While RBAC can be quite useful in limiting access to the Kubernetes API, it’s important to remember that anyone who can run arbitrary code inside the Kubernetes cluster can effectively obtain root privileges on the entire cluster. There are approaches that you can take to make such attacks harder and more expensive, and a correct RBAC setup is part of this defense. But if you are focused on hostile multitenant security, RBAC by itself is sufficient to protect you. You must isolate the Pods running in your cluster ...