Understand Amazon EKS created RBAC roles and users - Amazon EKS

Understand Amazon EKS created RBAC roles and users

When you create a Kubernetes cluster, several default Kubernetes identities are created on that cluster for the proper functioning of Kubernetes. Amazon EKS creates Kubernetes identities for each of its default components. The identities provide Kubernetes role-based authorization control (RBAC) for the cluster components. For more information, see Using RBAC Authorization in the Kubernetes documentation.

When you install optional Amazon EKS add-onsadd-ons to your cluster, additional Kubernetes identities might be added to your cluster. For more information about identities not addressed by this topic, see the documentation for the add-on.

You can view the list of Amazon EKS created Kubernetes identities on your cluster using the AWS Management Console or kubectl command line tool. All of the user identities appear in the kube audit logs available to you through Amazon CloudWatch.

AWS Management Console

.Prerequisite The IAM principal that you use must have the permissions described in Required permissionsRequired permissions.

  1. Open the Amazon EKS console.

  2. In the Clusters list, choose the cluster that contains the identities that you want to view.

  3. Choose the Resources tab.

  4. Under Resource types, choose Authorization.

  5. Choose, ClusterRoles, ClusterRoleBindings, Roles, or RoleBindings. All resources prefaced with eks are created by Amazon EKS. Additional Amazon EKS created identity resources are:

    • The ClusterRole and ClusterRoleBinding named aws-node. The aws-node resources support the Amazon VPC CNIAmazon VPC CNI plugin for Kubernetes, which Amazon EKS installs on all clusters.

    • A ClusterRole named vpc-resource-controller-role and a ClusterRoleBinding named vpc-resource-controller-rolebinding. These resources support the Amazon VPC resource controller, which Amazon EKS installs on all clusters.

In addition to the resources that you see in the console, the following special user identities exist on your cluster, though they’re not visible in the cluster’s configuration:

+

  • eks:cluster-bootstrap – Used for kubectl operations during cluster bootstrap.

  • eks:support-engineer – Used for cluster management operations.

    1. Choose a specific resource to view details about it. By default, you’re shown information in Structured view. In the top-right corner of the details page you can choose Raw view to see all information for the resource.

Kubectl

.Prerequisite The entity that you use (AWS Identity and Access Management (IAM) or OpenID Connect (OIDC)) to list the Kubernetes resources on the cluster must be authenticated by IAM or your OIDC identity provider. The entity must be granted permissions to use the Kubernetes get and list verbs for the Role, ClusterRole, RoleBinding, and ClusterRoleBinding resources on your cluster that you want the entity to work with. For more information about granting IAM entities access to your cluster, see Grant IAM users and roles access to Kubernetes APIs. For more information about granting entities authenticated by your own OIDC provider access to your cluster, see Grant users access to Kubernetes with an external OIDC provider. .To view Amazon EKS created identities using kubectl Run the command for the type of resource that you want to see. All returned resources that are prefaced with eks are created by Amazon EKS. In addition to the resources returned in the output from the commands, the following special user identities exist on your cluster, though they’re not visible in the cluster’s configuration:

  • eks:cluster-bootstrap – Used for kubectl operations during cluster bootstrap.

  • eks:support-engineer – Used for cluster management operations.

    ClusterRoles – ClusterRoles are scoped to your cluster, so any permission granted to a role applies to resources in any Kubernetes namespace on the cluster.

    The following command returns all of the Amazon EKS created Kubernetes ClusterRoles on your cluster.

    kubectl get clusterroles | grep eks

    In addition to the ClusterRoles returned in the output that are prefaced with, the following ClusterRoles exist.

  • aws-node – This ClusterRole supports the Amazon VPC CNIAmazon VPC CNI plugin for Kubernetes, which Amazon EKS installs on all clusters.

  • vpc-resource-controller-role – This ClusterRole supports the Amazon VPC resource controller, which Amazon EKS installs on all clusters.

    To see the specification for a ClusterRole, replace eks:k8s-metrics in the following command with a ClusterRole returned in the output of the previous command. The following example returns the specification for the eks:k8s-metrics ClusterRole.

    kubectl describe clusterrole eks:k8s-metrics

    An example output is as follows.

    Name:         eks:k8s-metrics
Labels:       <none>
Annotations:  <none>
PolicyRule:
  Resources         Non-Resource URLs  Resource Names  Verbs
  ---------         -----------------  --------------  -----
                    [/metrics]         []              [get]
  endpoints         []                 []              [list]
  nodes             []                 []              [list]
  pods              []                 []              [list]
  deployments.apps  []                 []              [list]

    ClusterRoleBindings – ClusterRoleBindings are scoped to your cluster.

    The following command returns all of the Amazon EKS created Kubernetes ClusterRoleBindings on your cluster.

    kubectl get clusterrolebindings | grep eks

    In addition to the ClusterRoleBindings returned in the output, the following ClusterRoleBindings exist.

  • aws-node – This ClusterRoleBinding supports the Amazon VPC CNIAmazon VPC CNI plugin for Kubernetes, which Amazon EKS installs on all clusters.

  • vpc-resource-controller-rolebinding – This ClusterRoleBinding supports the Amazon VPC resource controller, which Amazon EKS installs on all clusters.

To see the specification for a ClusterRoleBinding, replace eks:k8s-metrics in the following command with a ClusterRoleBinding returned in the output of the previous command. The following example returns the specification for the eks:k8s-metrics ClusterRoleBinding.

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kubectl describe clusterrolebinding eks:k8s-metrics

+ An example output is as follows.

+

Name:         eks:k8s-metrics
Labels:       <none>
Annotations:  <none>
Role:
  Kind:  ClusterRole
  Name:  eks:k8s-metrics
Subjects:
  Kind  Name             Namespace
  ----  ----             ---------
  User  eks:k8s-metrics

+ Roles – Roles are scoped to a Kubernetes namespace. All Amazon EKS created Roles are scoped to the kube-system namespace.

+ The following command returns all of the Amazon EKS created Kubernetes Roles on your cluster.

+

kubectl get roles -n kube-system | grep eks

+ To see the specification for a Role, replace eks:k8s-metrics in the following command with the name of a Role returned in the output of the previous command. The following example returns the specification for the eks:k8s-metrics Role.

+

kubectl describe role eks:k8s-metrics -n kube-system

+ An example output is as follows.

+

Name:         eks:k8s-metrics
Labels:       <none>
Annotations:  <none>
PolicyRule:
  Resources         Non-Resource URLs  Resource Names             Verbs
  ---------         -----------------  --------------             -----
  daemonsets.apps   []                 [aws-node]                 [get]
  deployments.apps  []                 [vpc-resource-controller]  [get]

+ RoleBindings – RoleBindings are scoped to a Kubernetes namespace. All Amazon EKS created RoleBindings are scoped to the kube-system namespace.

+ The following command returns all of the Amazon EKS created Kubernetes RoleBindings on your cluster.

+

kubectl get rolebindings -n kube-system | grep eks

+ To see the specification for a RoleBinding, replace eks:k8s-metrics in the following command with a RoleBinding returned in the output of the previous command. The following example returns the specification for the eks:k8s-metrics RoleBinding.

+

kubectl describe rolebinding eks:k8s-metrics -n kube-system

+ An example output is as follows.

+

Name:         eks:k8s-metrics
Labels:       <none>
Annotations:  <none>
Role:
  Kind:  Role
  Name:  eks:k8s-metrics
Subjects:
  Kind  Name             Namespace
  ----  ----             ---------
  User  eks:k8s-metrics