Kubernetes: Diffrerence between RoleBinding and ClusterRoleBinding

Question

What is the difference between RoleBinding and ClusterRoleBinding? And what are the usages of them?

Answer 1

A rolebinding is namespace scoped and clusterrolebinding is cluster scoped i.e across all namespace.

ClusterRoles and ClusterRoleBindings are useful in the following cases:

1. Give permissions for non-namespaced resources like nodes

2. Give permissions for resources in all the namespaces of a cluster

3. Give permissions for non-resource endpoints like /healthz

A RoleBinding can also reference a ClusterRole to grant the permissions defined in that ClusterRole to resources inside the RoleBinding's namespace. This kind of reference lets you define a set of common roles across your cluster, then reuse them within multiple namespaces.

Answer 2

Please refer the Kubernetes documentation here

A Role always sets permissions within a particular namespace; when you create a Role, you have to specify the namespace it belongs in.

ClusterRole, by contrast, is a non-namespaced resource. The resources have different names (Role and ClusterRole) because a Kubernetes object always has to be either namespaced or not namespaced; it can’t be both.