Tanzu Kubernetes
clusters include default PodSecurityPolicy that you can bind to for privileged and restricted workload deployment.
About Default Pod Security Policy
This section provides YAML and CLI commands for creating role binding objects to default pod security policy, including ClusterRoleBinding and RoleBinding. For more information, see
Using Pod Security Policies with Tanzu Kubernetes Clusters
.
A RoleBinding grants permissions within a specific namespace whereas a ClusterRoleBinding grants permissions cluster-wide. The decision to use a RoleBindings or ClusterRoleBinding depends on your use case. For example, if you use a ClusterRoleBinding and configure subjects to use
system:serviceaccounts:<namespace>
, you can bind to a PSP before the namespace is created. For more information, see
RoleBinding and ClusterRoleBinding
in the Kubernetes documentation.
Example 1: ClusterRoleBinding to Run a Privileged Set of Workloads
The following
kubectl
command creates a ClusterRoleBinding that grants access to authenticated users run a privileged set of workloads using the default PSP
vmware-system-privileged
.
Warning:
Applying Example 1, declaratively or imperatively, allows the deployment of privileged workloads cluster-wide. In effect Example 1 disables native security controls and should be used with caution and full awareness of the implications. For tighter security, consider Examples 2, 3, and 4.
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
name: psp:privileged
rules:
- apiGroups: ['policy']
resources: ['podsecuritypolicies']
verbs: ['use']
resourceNames:
- vmware-system-privileged
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
name: all:psp:privileged
roleRef:
kind: ClusterRole
name: psp:privileged
apiGroup: rbac.authorization.k8s.io
subjects:
- kind: Group
name: system:serviceaccounts
apiGroup: rbac.authorization.k8s.io
As an alternative to applying YAML, you can run the following
kubectl
command.
kubectl create clusterrolebinding default-tkg-admin-privileged-binding --clusterrole=psp:vmware-system-privileged --group=system:authenticated
Example 2: RoleBinding to Run a Privileged Set of Workloads
The following
kubectl
command creates a RoleBinding that grants access to all service accounts within the default namespace to run a privileged set of workloads using the default PSP
vmware-system-privileged
.
kind: RoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: rolebinding-default-privileged-sa-ns_default
namespace: default
roleRef:
kind: ClusterRole
name: psp:vmware-system-privileged
apiGroup: rbac.authorization.k8s.io
subjects:
- kind: Group
apiGroup: rbac.authorization.k8s.io
name: system:serviceaccounts
As an alternative to applying YAML, you can run the following
kubectl
command.
kubectl create rolebinding rolebinding-default-privileged-sa-ns_default --namespace=default --clusterrole=psp:vmware-system-privileged --group=system:serviceaccounts
Example 3: ClusterRoleBinding to Run a Restricted Set of Workloads
The following YAML creates a ClusterRoleBinding that grants authenticated users cluster-wide access to run a restricted set of workloads using the default PSP
vmware-system-restricted
.
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
name: psp:authenticated
subjects:
- apiGroup: rbac.authorization.k8s.io
kind: Group
name: system:authenticated
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: psp:vmware-system-restricted
As an alternative to applying YAML, you can run the following
kubectl
command.
kubectl create clusterrolebinding psp:authenticated --clusterrole=psp:vmware-system-restricted --group=system:authenticated
Example 4: RoleBinding to Run a Restricted Set of Workloads
The following YAML creates a RoleBinding that grants access to all service accounts within a specific namespace to run a restricted set of workloads using the default PSP
vmware-system-restricted
.
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
name: psp:serviceaccounts
namespace: some-namespace
subjects:
- apiGroup: rbac.authorization.k8s.io
kind: Group
name: system:serviceaccounts
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: psp:vmware-system-restricted
As an alternative to applying YAML, you can run the following
kubectl
command.
kubectl create rolebinding psp:serviceaccounts --clusterrole=psp:vmware-system-restricted --group=system:serviceaccounts