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Container Service for Kubernetes:Grant RBAC permissions to RAM users or RAM roles

Last Updated:Jan 08, 2024

Role-based access control (RBAC) regulates access to resources based on the roles of users. You can grant multiple permissions to cluster roles and configure different permission policies for different roles. This topic describes how to grant Resource Access Management (RAM) users or RAM roles RBAC permissions on a Container Service for Kubernetes (ACK) cluster.

Table of contents

Configurations

Configuration item

Description

Default permissions

  • By default, only Alibaba Cloud accounts and cluster owners have administrator permissions on Kubernetes resources in ACK clusters.

  • By default, RAM users or RAM roles other than the cluster owners do not have the permissions to access Kubernetes resources in ACK clusters.

Authorization methods

Note

To assign RBAC roles to a RAM user or RAM role, make sure that the RAM user or RAM role is granted at least read-only permissions on the specified cluster in the RAM console.

Authorization models

You can grant permissions to one or more RAM users or RAM roles at a time.

Note

To ensure data security, you are not allowed to modify RAM policies that are attached to your RAM users or RAM roles in the ACK console. You must read the instructions on the authorization page, log on to the RAM console, and then modify the RAM policies.

Grant RBAC permissions to RAM users or RAM roles

  1. Log on to the ACK console. In the left-side navigation pane, click Authorizations.

  2. On the Select RAM User wizard page of the Authorizations page, grant permissions.

    • Grant permissions to a RAM user

      Click the RAM Users tab, find the RAM user that you want to manage in the list, and then click Modify Permissions to open the Permission Management panel.

    • Grant permissions to a RAM role

      Click the RAM Roles tab, specify RAM Role Name, and then click Modify Permissions to open the Permission Management panel.

    Note

    If you want to use a RAM user or RAM role to grant permissions to other RAM users or RAM roles, make sure that the RAM user or RAM role has the required RAM permissions on the cluster that you want to manage. For more information, see Create a custom RAM policy. In addition, the RAM user or RAM role must be assigned the cluster-admin role or administrator role of the cluster.

  3. Click Add Permissions, specify Clusters and Namespace for the RAM user or RAM role, select a predefined role, and then click Submit.

    Note
    • ACK provides the following predefined roles: Administrator, O&M Engineer, Developer, and Restricted User. You can use these roles to regulate access to resources in the ACK console in most scenarios. In addition, you can use custom roles to control permissions on clusters.

    • You can assign one predefined role and multiple custom roles of a cluster or namespace to a RAM user or RAM role.

    • If you want to authorize a RAM user or RAM role to manage all clusters (including newly created clusters), select All Clusters in the Clusters column when you assign a predefined role to the RAM user or RAM role.

    Show the description of predefined roles

    Predefined role

    RBAC permission on cluster resources

    Administrator

    Read and write permissions on resources in all namespaces.

    O&M Engineer

    Read and write permissions on visible Kubernetes resources in the console in all namespaces and read-only permissions on nodes, persistent volumes (PVs), namespaces, and quotas.

    Developer

    Read and write permissions on visible resources in the console in all or specified namespaces.

    Restricted User

    Read-only permissions on visible resources in the console in all or specified namespaces.

    Custom

    The permissions of a custom role are determined by the ClusterRole that you select. Before you select a ClusterRole, check the permissions of the ClusterRole and make sure that you grant only the required permissions to the RAM user or RAM role. The following section describes how to view the permissions of a custom role.

    Important

    After a RAM user or RAM role is assigned the cluster-admin role, the RAM user or RAM role has the same permissions as the Alibaba Cloud account to which the RAM user or RAM role belongs. The RAM user or RAM role has full control over all resources within the cluster. Exercise caution if you want to assign the cluster-admin role to a RAM user or RAM role.

    Show how to view the permissions of a custom role

    Log on to a node and run the following command to view the RBAC roles in the cluster:

    kubectl get clusterrole

    Expected output

    NAME                                                                   AGE
    admin                                                                  13d
    alibaba-log-controller                                                 13d
    alicloud-disk-controller-runner                                        13d
    cluster-admin                                                          13d
    cs:admin                                                               13d
    edit                                                                   13d
    flannel                                                                13d
    kube-state-metrics                                                     22h
    node-exporter                                                          22h
    prometheus-k8s                                                         22h
    prometheus-operator                                                    22h
    system:aggregate-to-admin                                              13d
    ....  
    system:volume-scheduler                                                13d
    view                                                                   13d         

    Run the following command to query the details of a role, for example, the cluster-admin role:

    Important

    After a RAM user or RAM role is assigned the cluster-admin role, the RAM user or RAM role has the same permissions as the Alibaba Cloud account to which the RAM user or RAM role belongs. The RAM user or RAM role has full control over all resources within the cluster. Exercise caution if you want to assign the cluster-admin role to a RAM user or RAM role.

    kubectl get clusterrole cluster-admin -o yaml

    Expected output

    apiVersion: rbac.authorization.k8s.io/v1
    kind: ClusterRole
    metadata:
      annotations:
        rbac.authorization.kubernetes.io/autoupdate: "true"
      creationTimestamp: 2022-12-30T08:31:15Z
      labels:
        kubernetes.io/bootstrapping: rbac-defaults
      name: cluster-admin
      resourceVersion: "57"
      selfLink: /apis/rbac.authorization.k8s.io/v1/clusterroles/cluster-admin
      uid: 2f29f9c5-cdf9-11e8-84bf-00163e0b2f97
    rules:
    - apiGroups:
      - '*'
      resources:
      - '*'
      verbs:
      - '*'
    - nonResourceURLs:
      - '*'
      verbs:
      - '*'
  4. After you click Submit, follow the on-screen instructions.

    • If the page displays that the authorization is complete, the RBAC role is assigned to the RAM user or RAM role.

    After the authorization is complete, you can log on to the ACK console as the RAM user or RAM role to manage the specified cluster.

Use a RAM user or RAM role to grant RBAC permissions to other RAM users or RAM roles

By default, you cannot use a RAM user or RAM role to grant RBAC permissions to other RAM users or RAM roles. If you want to use a RAM user or RAM role to grant RBAC permissions to other RAM users or RAM roles, you must first use the Alibaba Cloud account or a RAM user that is assigned the Administrator role of all clusters to grant the required permissions to the RAM user or RAM role.

RAM permissions

You must attach a RAM policy to the RAM user or RAM role. The RAM policy must provide the following permissions:

  • The permissions to view other RAM users that belong to the same Alibaba Cloud account.

  • The permissions to attach RAM policies to other RAM users or RAM roles.

  • The permissions to view information about ACK clusters.

  • The permissions to view permissions of RBAC roles.

  • The permissions to assign RBAC roles to other RAM users or RAM roles.

Log on to the RAM console, create a RAM policy based on the following content, and then attach the RAM policy to the RAM user or RAM role. For more information, see Create a custom RAM policy.

Note

Replace xxxxxx with the name of the RAM policy you want to authorize the RAM user or RAM role to attach to other RAM users or RAM roles. If you replace xxxxxx with an asterisk (*), the RAM user or RAM role is authorized to attach all RAM policies to other RAM users or RAM roles.

{
    "Statement": [{
            "Action": [
                "ram:Get*",
                "ram:List*",
                "cs:Get*",
                "cs:Describe*",
                "cs:List*",
                "cs:GrantPermission"
            ],
            "Resource": "*",
            "Effect": "Allow"
        },
        {
            "Action": [
                "ram:AttachPolicyToUser",
                "ram:AttachPolicy"
            ],
            "Effect": "Allow",
            "Resource":  [
                "acs:ram:*:*:policy/xxxxxx",
                "acs:*:*:*:user/*"
            ]
        }
    ],
    "Version": "1"
}

After the RAM policy is attached to the RAM user or RAM role, you can use the RAM user or RAM role to attach specified RAM policies to other RAM users or RAM roles.

RBAC permissions

After you attach the preceding RAM policy to the RAM user or RAM role, you must assign the Administrator or cluster-admin role to the RAM user or RAM role to allow them to access the specified cluster or namespace. For more information, see Grant RBAC permissions to RAM users or RAM roles.

Set a RAM user or RAM role as a permission administrator

If you do not want to use an Alibaba Cloud account to assign RBAC roles to RAM users or RAM roles, you can set a RAM user or RAM role as a permission administrator and then use the RAM user or RAM role to grant permissions to other RAM users or RAM roles.

  1. Log on to the RAM console and find the RAM user or RAM role that you want to use.

    • RAM user

      In the left-side navigation pane of the RAM console, choose Identities > Users. Find the RAM user that you want to use and click Add Permissions in the Actions column.

    • RAM role

      In the left-side navigation pane of the RAM console, choose Identities > Roles. Find the RAM role that you want to use and click Add Permissions in the Actions column.

  2. In the Add Permissions panel, specify Authorized Scope, select System Policy, find and click the AliyunRAMReadOnlyAccess and AliyunCSFullAccess system policies to add them to the right-side Selected list, and then click OK. After the policies are attached, click Complete.

  3. Log on to the ACK console with your Alibaba Cloud account and assign the Administrator role of all clusters to the RAM user or RAM role.

    For more information, see Grant RBAC permissions to RAM users or RAM roles.

    After the preceding steps are complete, the RAM user or RAM role is set as a permission administrator. You can use the RAM user or RAM role to grant RAM permissions and RBAC permissions to other RAM users or RAM roles.

Error codes for insufficient permissions

If you do not have the required permissions when you use the ACK console or call the ACK API to perform an operation, the console or API returns an error code that indicates the required permissions. The following table describes the error codes that indicate the required RBAC permissions on the cluster.

Error code or error message

Required RBAC permission on the cluster

ForbiddenCheckControlPlaneLog

Administrator or O&M engineer permissions are required.

ForbiddenHelmUsage

Administrator permissions are required.

ForbiddenRotateCert

Administrator permissions are required.

ForbiddenAttachInstance

Administrator or O&M engineer permissions are required.

ForbiddenUpdateKMSState

Administrator or O&M engineer permissions are required.

Forbidden get trigger

Administrator, O&M engineer, or developer permissions are required.

ForbiddenQueryClusterNamespace

Administrator, O&M engineer, developer, or restricted user permissions are required.

References