Managing Role-based Access Control | Cluster Administration

Overview
Viewing roles and bindings
Managing role bindings

Overview

You can use the CLI to view RBAC resources and the administrator CLI to manage the roles and bindings.

Dedicated cluster administrators can view but not manage cluster roles. They can manage cluster role bindings and manage local roles and bindings.

Viewing roles and bindings

Roles can be used to grant various levels of access both cluster-wide as well as at the project-scope. users and groups can be associated with, or bound to, multiple roles at the same time. You can view details about the roles and their bindings using the oc describe command.

users with the dedicated-cluster-admin role can view but not manage cluster roles. They can manage cluster role bindings and manage local roles and bindings. users with the admin default cluster role bound locally can manage roles and bindings in that project.

Review a full list of verbs in the Evaluating Authorization section.

Viewing cluster roles

Viewing cluster role bindings

To view the current set of cluster role bindings, which show the users and groups that are bound to various roles:

$ oc describe clusterrolebinding.rbac

Viewing local roles and bindings

All of the default cluster roles can be bound locally to users or groups.

The local role bindings are also viewable.

To view the current set of local role bindings, which show the users and groups that are bound to various roles:

$ oc describe rolebinding.rbac

By default, the current project is used when viewing local role bindings. Alternatively, a project can be specified with the -n flag. This is useful for viewing the local role bindings of another project, if the user already has the admin default cluster role in it.

$ oc describe rolebinding.rbac -n joe-project
Name:		admin
Labels:		<none>
Annotations:	<none>
Role:
  Kind:	ClusterRole
  Name:	admin
Subjects:
  Kind	Name	Namespace
  ----	----	---------
  user	joe


Name:		system:deployers
Labels:		<none>
Annotations:	<none>
Role:
  Kind:	ClusterRole
  Name:	system:deployer
Subjects:
  Kind			Name		Namespace
  ----			----		---------
  ServiceAccount	deployer	joe-project


Name:		system:image-builders
Labels:		<none>
Annotations:	<none>
Role:
  Kind:	ClusterRole
  Name:	system:image-builder
Subjects:
  Kind			Name	Namespace
  ----			----	---------
  ServiceAccount	builder	joe-project


Name:		system:image-pullers
Labels:		<none>
Annotations:	<none>
Role:
  Kind:	ClusterRole
  Name:	system:image-puller
Subjects:
  Kind	Name					Namespace
  ----	----					---------
  Group	system:serviceaccounts:joe-project

Managing role bindings

Adding, or binding, a role to users or groups gives the user or group the relevant access granted by the role. You can add and remove roles to and from users and groups using oc adm policy commands.

When managing a user or group’s associated roles for local role bindings using the following operations, a project may be specified with the -n flag. If it is not specified, then the current project is used.

Table 1. Local role binding operations
Command	Description
`$ oc adm policy who-can <verb> <resource>`	Indicates which users can perform an action on a resource.
`$ oc adm policy add-role-to-user <role> <username>`	Binds a given role to specified users in the current project.
`$ oc adm policy remove-role-from-user <role> <username>`	Removes a given role from specified users in the current project.
`$ oc adm policy remove-user <username>`	Removes specified users and all of their roles in the current project.
`$ oc adm policy add-role-to-group <role> <groupname>`	Binds a given role to specified groups in the current project.
`$ oc adm policy remove-role-from-group <role> <groupname>`	Removes a given role from specified groups in the current project.
`$ oc adm policy remove-group <groupname>`	Removes specified groups and all of their roles in the current project.
`--rolebinding-name=`	Can be used with `oc adm policy` commands to retain the rolebinding name assigned to a user or group.

For example, you can add the admin role to the alice user in joe-project by running:

$ oc adm policy add-role-to-user admin alice -n joe-project

You can then view the local role bindings and verify the addition in the output:

$ oc describe rolebinding.rbac -n joe-project
Name:		admin
Labels:		<none>
Annotations:	<none>
Role:
  Kind:	ClusterRole
  Name:	admin
Subjects:
  Kind	Name	Namespace
  ----	----	---------
  user	joe


Name:		admin-0 (1)
Labels:		<none>
Annotations:	<none>

Role:
  Kind:  ClusterRole
  Name:  admin
Subjects:
  Kind  Name   Namespace
  ----  ----   ---------
  user  alice (2)


Name:		system:deployers
Labels:		<none>
Annotations:	<none>
Role:
  Kind:	ClusterRole
  Name:	system:deployer
Subjects:
  Kind			Name		Namespace
  ----			----		---------
  ServiceAccount	deployer	joe-project


Name:		system:image-builders
Labels:		<none>
Annotations:	<none>
Role:
  Kind:	ClusterRole
  Name:	system:image-builder
Subjects:
  Kind			Name	Namespace
  ----			----	---------
  ServiceAccount	builder	joe-project


Name:		system:image-pullers
Labels:		<none>
Annotations:	<none>
Role:
  Kind:	ClusterRole
  Name:	system:image-puller
Subjects:
  Kind	Name					Namespace
  ----	----					---------
  Group	system:serviceaccounts:joe-project

1	A new role binding is created with a default name, incremented as necessary. To specify an existing role binding to modify, use the `--rolebinding-name` option when adding the role to the user.
2	The user alice is added.

Managing Role-based Access Control (RBAC)