Set up role-based access control (RBAC)
Authentication is often combined with Kubernetes role-based access control (RBAC) to provide more finely grained access control to clusters for authenticated users and service accounts. It is recommended to create RBAC policies that use group names instead of user identifiers. By linking your RBAC policies explicitly to groups, you can manage user access privileges entirely with your identity provider, so the cluster doesn't need to be updated every time user privileges change. Note that to configure access control based on membership of security groups with OIDC, you must ensure that GKE Identity Service is set up to support getting group membership information from your identity provider.
Example
If you want certain authenticated users to have access to the cluster's Pods, create a ClusterRole
that grants access to these resources, as in the following example:
apiVersion: rbac.authorization.k8s.io/v1 kind: ClusterRole metadata: name: pod-reader rules: - apiGroups: [""] # The resource type for which access is granted resources: ["pods"] # The permissions granted by the ClusterRole verbs: ["get", "watch", "list"]
You then create a corresponding ClusterRoleBinding
to grant the permissions in the ClusterRole
to the relevant users—in this case, members of the us-east1-cluster-admins
security group and the user with ID u98523-4509823
:
apiVersion: rbac.authorization.k8s.io/v1 kind: ClusterRoleBinding metadata: name: read-pods-admins subjects: # Grants anyone in the "us-east1-cluster-admins" group # read access to Pods in any namespace within this cluster. - kind: Group name: gid-us-east1-cluster-admins # Name is case-sensitive apiGroup: rbac.authorization.k8s.io # Grants this specific user read access to Pods in any # namespace within this cluster - kind: User name: uid-u98523-4509823 apiGroup: rbac.authorization.k8s.io roleRef: kind: ClusterRole name: pod-reader apiGroup: rbac.authorization.k8s.io
In the following example, this ClusterRoleBinding
grants permissions in the ClusterRole
to the relevant group with ID 12345678-BBBb-cCCCC-0000-123456789012
. Note that this setting is relevant only for Azure AD providers and is available for Google Distributed Cloud clusters.
apiVersion: rbac.authorization.k8s.io/v1 kind: ClusterRoleBinding metadata: name: pod-reader-binding subjects: # Retrieves group information for the group ID mentioned - kind: Group name: 12345678-BBBb-cCCCC-0000-123456789012 apiGroup: rbac.authorization.k8s.io
For more information about using RBAC, see Configure role-based access control and Using RBAC Authorization.
Create an RBAC role for Google Cloud console access
Users authenticated using OIDC providers can log in to clusters from the Google Cloud console as well as the command line.
Authenticated users who want to access a cluster's resources in the Google Cloud console
need to have the relevant Kubernetes permissions to do so. If you don't want to grant those users more extensive permissions, such as those of a cluster admin, you can create a custom RBAC role that includes the minimum permissions to view the cluster's nodes, persistent volumes, pods, and storage classes. You can define this set of
permissions by creating a ClusterRole
RBAC resource,
cloud-console-reader
, in the cluster.
cloud-console-reader
grants its users the get
, list
, and watch
permissions on the cluster's nodes, persistent volumes, pods and storage classes,
which allow them to see details about these resources.
kubectl
To create the cloud-console-reader
ClusterRole
and apply it to the cluster, run the
following command:
cat <<EOF > cloud-console-reader.yaml
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: cloud-console-reader
rules:
- apiGroups: [""]
resources: ["nodes", "persistentvolumes", "pods"]
verbs: ["get", "list", "watch"]
- apiGroups: ["storage.k8s.io"]
resources: ["storageclasses"]
verbs: ["get", "list", "watch"]
EOF
kubectl apply -f cloud-console-reader.yaml
You can then grant this ClusterRole
to users when setting up your permission policies, as described in the previous section. Note that users also need IAM permissions to view clusters in the Google Cloud console.