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Impersonating the system:admin user

You can configure API requests to impersonate users or groups to test permissions and troubleshoot access issues in OKD.

API impersonation

You can configure API requests in OKD to act as another user. Impersonation allows you to perform actions on behalf of another account without switching credentials.

Impersonating the system:admin user

You can grant a user permission to impersonate system:admin, which grants them cluster administrator permissions.

Procedure

  • To grant a user permission to impersonate system:admin, run the following command:

    $ oc create clusterrolebinding <any_valid_name> --clusterrole=sudoer --user=<username>

    You can alternatively apply the following YAML to grant permission to impersonate system:admin:

    apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: <any_valid_name>
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: sudoer
subjects:
- apiGroup: rbac.authorization.k8s.io
  kind: User
  name: <username>

Impersonating the system:admin group

To impersonate a user who has cluster administration privileges through group membership, you must specify both the user and the associated groups in the impersonation command.

Procedure

  • To grant a user permission to impersonate a system:admin by impersonating the associated cluster administration groups, run the following command:

    $ oc create clusterrolebinding <any_valid_name> --clusterrole=sudoer --as=<user> \
--as-group=<group1> --as-group=<group2>

Adding unauthenticated groups to cluster roles

Grant unauthenticated users access to specific cluster roles to enable features that require cluster access without authentication, such as external webhooks or automated token management.

You can add unauthenticated users to the following cluster roles:

  • system:scope-impersonation

  • system:webhook

  • system:oauth-token-deleter

  • self-access-reviewer

Always verify compliance with your organization’s security standards when modifying unauthenticated access.
Prerequisites

  • You have access to the cluster as a user with the cluster-admin role.

  • You have installed the OpenShift CLI (oc).

Procedure

  1. Create a YAML file named add-<cluster_role>-unauth.yaml and add the following content:

    apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
 annotations:
   rbac.authorization.kubernetes.io/autoupdate: "true"
 name: <cluster_role>access-unauthenticated
roleRef:
 apiGroup: rbac.authorization.k8s.io
 kind: ClusterRole
 name: <cluster_role>
subjects:
 - apiGroup: rbac.authorization.k8s.io
   kind: Group
   name: system:unauthenticated

  2. Apply the configuration by running the following command:

    $ oc apply -f add-<cluster_role>.yaml

Additional resources