:Authorization overview

ACS authorization system

The authorization system of ACS consists of RAM authorization for computing resources and RBAC authorization for ACS clusters. The following figure shows the ACS authorization system.

• RAM authorization involves cluster O&M operations. ACS clusters are a type of Container Service for Kubernetes (ACK) Serverless cluster, and you must call the ACK API to perform O&M operations on ACS clusters. Therefore, you must acquire permissions to call the API operations of ACK and other Alibaba Cloud services. You can call these API operations to perform the following O&M operations:

  • Create, view, and delete clusters.

  • Manage RBAC authorization.

  • Monitor clusters and manage logs and events.

• RBAC authorization is used to grant namespace-level or cluster-wide permissions on Kubernetes resources in ACS clusters. This allows you to grant the permissions to create, delete, modify, and view the following types of Kubernetes resources:

  • Workload resources: such as Deployment, StatefulSet, Job, CronJob, pod, ReplicaSet, and HorizontalPodAutoscaler (HPA).

  • Network resources: such as Service, Ingress, and NetworkPolicy.

  • Storage resources: such as persistent volume (PV), persistent volume claim (PVC), and StorageClass.

  • Namespace, ConfigMap, and Secret.

RAM authorization

When an enterprise interfaces its system with RAM, the O&M engineer needs to use a RAM user or RAM role to manage cloud resources. By default, RAM users or RAM roles do not have permissions to call the APIs of cloud services. You must first grant the required permissions to the RAM user or RAM role.

You can perform RAM authorization by using one of the following methods:

• Attach system policies: You can use this method to grant a RAM user or RAM role the read and write permissions on global resources. We recommend that you use system policies to grant O&M permissions on all clusters that belong to your Alibaba Cloud. For more information, see Grant permissions to a RAM user or RAM role.

  The following table describes the commonly used system policies related to ACS. You can select system policies based on your requirements.

  System policy	Description
  AliyunCSFullAccess	This policy provides RAM users or RAM roles with permissions to call all ACK API operations when creating an ACS cluster. Important The scope of this permission includes all ACK clusters except for ACS clusters. Use this policy with caution. This policy involves only RAM authorization for ACK API operations. If you want to manage applications in an ACS cluster, you must perform RBAC authorization. For more information, see RBAC authorization.
  AliyunCSReadOnlyAccess	This policy provides RAM users or RAM roles with permissions to call all read-only API operations of ACK. The scope of this permission includes all ACK clusters except for ACS clusters. Use this policy with caution.
  AliyunACCFullAccess	This policy provides RAM users or RAM roles with access permissions for all ACS API operations.
  AliyunACCReadOnlyAccess	This policy provides RAM users or RAM roles with read-only permissions for all ACS API operations.
  AliyunVPCReadOnlyAccess	This policy provides RAM users or RAM roles with permissions to specify a virtual private cloud (VPC) for an ACS cluster to be created.
  AliyunContainerRegistryFullAccess	This policy provides RAM users or RAM roles with permissions for business images within the Alibaba Cloud account.
  AliyunLogReadOnlyAccess	This policy provides RAM users or RAM roles with permissions to select an existing log project to store the audit logs of an ACS cluster to be created or view the configuration inspection information of an ACS cluster.
  AliyunRAMFullAccess	This policy provides RAM users or RAM roles with permissions to manage global authorization within an Alibaba Cloud account.
  AliyunEBSFullAccess	This policy provides RAM users or RAM roles with permissions to use all features of the disk storage service.
  AliyunARMSReadOnlyAccess	This policy provides RAM users or RAM roles with permissions to view the monitoring data of the Managed Service for Prometheus plug-in.
  AliyunKMSReadOnlyAccess	This policy provides RAM users or RAM roles with permissions to view keys in the Key Management Service (KMS) for an ACS cluster to be created.

• Attach custom policies: You can use this method to control the permissions of a RAM user or RAM role on cloud resources in a fine-grained manner. If the RAM user or RAM role needs to develop applications based on SDKs, you can use custom policies to control permissions on API operations.

  • To enforce application-level access control, you can use RAM Roles for Service Accounts (RRSA) to authorize different pods to access different cloud services. For more information, see Use RRSA to authorize different pods to access different cloud services.

  For example, you can use the following policy to grant read permissions to a RAM user or RAM role on an Object Storage Service (OSS) bucket:

  {
      "Version": "1",
      "Statement": [
          {
              "Effect": "Allow",
              "Action": [
                        "oss:ListBuckets",
                        "oss:GetBucketStat",
                        "oss:GetBucketInfo",
                        "oss:GetBucketTagging",
                        "oss:GetBucketAcl" 
                        ],    
              "Resource": "acs:oss:*:*:*"
          },
          {
              "Effect": "Allow",
              "Action": [
                  "oss:ListObjects",
                  "oss:GetBucketAcl"
              ],
              "Resource": "acs:oss:*:*:myphotos"
          },
          {
              "Effect": "Allow",
              "Action": [
                  "oss:GetObject",
                  "oss:GetObjectAcl"
              ],
              "Resource": "acs:oss:*:*:myphotos/*"
          }
      ]
  }

Roles and ClusterRoles

A Role or ClusterRole in RBAC contains rules that represent a set of permissions. These permissions are additive and do not contain rules that forbid operations.

A Role is a namespaced resource and defines permissions within a particular namespace. When you create a Role, you must specify the namespace to which the Role belongs.

A ClusterRole is a non-namespaced resource and defines cluster-wide permissions. The two types of roles have different names because a Kubernetes object must be either namespaced or non-namespaced.

For more information about how to create a Kubernetes ClusterRole or Role, see Customize an RBAC role.

RBAC-based access control

To authorize a RAM user or RAM role to manage the specified Kubernetes resources in a cluster, such as obtaining the pod and node information, go to the authorization page of the ACS console and grant the RAM user or RAM role permissions on data plane resources.