Add an Elastic Kubernetes Service Instance Profile - User Impersonation Cluster

This guide describes how to manage access to an Elastic Kubernetes Service (EKS) Instance Profile - User Impersonation cluster via the StrongDM Admin UI. This cluster type supports AWS IAM role authentication for EKS resources and gateways running in EC2. EKS clusters are added and managed in both the Admin UI and the AWS Management Console.

Prerequisites

Before you begin, ensure that the EKS endpoint you are connecting is accessible from one of your StrongDM gateways or relays. See our  Nodes  guide for more information. It is recommended to have the Audit and Authentication logs enabled for the EKS cluster, as these logs can be very helpful in troubleshooting any connection issues that you may encounter.

Credentials-reading order

During authentication with your AWS resource, the system looks for credentials in the following places in this order:

1. Environment variables (if the Enable Environment Variables box is checked)
2. Shared credentials file
3. EC2 role or ECS profile

As soon as the relay or gateway finds credentials, it stops searching and uses them. Due to this behavior, we recommend that all similar AWS resources with these authentication options use the same method when added to StrongDM.

For example, if you are using environment variables for AWS Management Console and using EC2 role authentication for an EKS cluster, when users attempt to connect to the EKS cluster through the gateway or relay, the environment variables are found and used in an attempt to authenticate with the EKS cluster, which then fails. We recommend using the same type for all such resources to avoid this problem at the gateway or relay level. Alternatively, you can segment your network by creating subnets with their own relays and sets of resources, so that the relays can be configured to work correctly with just those resources.

Cluster Setup

You can find information about your cluster in the AWS Management Console on your EKS cluster’s general configuration page.

Manage the IAM Role

1. In the AWS Management Console, go to Identity and Access Management (IAM) > Roles.
2. Create a role to be used for accessing the cluster, or select an existing role to be used.
3. Attach or set the role to what you are using to run your relay (for example, an EC2 instance, ECS task, EKS pod, and so forth). See AWS documentation for information on how to  attach roles to EC2 instances,  set the role of an ECS task,  and  set the role of a pod in EKS.
4. Copy the Role ARN (the Amazon Resource Name specifying the role).

Grant the Role the Ability to Interact With the Cluster

1. To create a ClusterRole/ClusterRoleBinding with minimum privileges require for healthcheck and user impersonation. Create a new yaml file named readOnly.yml with the following contents (you can change the names of the ClusterRole/CluserRoleBindings to fit your naming conventions).

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: k8s-read
rules:
- apiGroups:
  - '*'
  resources:
  - deployments
  - pods
  - namespaces
  verbs:
  - get
  - describe
- apiGroups:
  - ""
  resources:
  - "users"
  - "groups"
  verbs:
  - impersonate
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: k8s-read
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: k8s-read
subjects:
- apiGroup: rbac.authorization.k8s.io
  kind: Group
  name: k8s-read

2. Ensure your kubectl context is set to the the intended EKS cluster, then add the ClusterRole/ClusterRoleBinding by running

kubectl apply -f readOnly.yml

3. While authenticated to the cluster using your existing connection method, run the following command to edit the aws-auth ConfigMap (YAML file) within Kubernetes:

kubectl edit -n kube-system configmap/aws-auth

      4. Copy the following snippet and paste it into the file under the data: heading, as shown:

data:

  mapRoles: |

    - rolearn: <ARN_OF_INSTANCE_ROLE>

      username: <USERNAME>

      groups:

        - <GROUP>

      5.In that snippet, do the following:

• Replace <ARN_OF_INSTANCE_ROLE> with the ARN of the instance role.
• Under groups:, replace <GROUP> with the appropriate group for the permissions level you want this StrongDM connection to have (see  Kubernetes Roles  for more details).

  Example:

data:

  mapRoles: |

    - rolearn: arn:aws:iam::123456789012:role/Example

      username: sdm-user

      groups:

        - k8s-read

The name under groups: in the mapRoles block must match the subject name in the desired ClusterRoleBinding, not the name of the ClusterRoleBinding itself. Save the file and exit your text editor.

Add Your EKS Instance Profile Cluster in the StrongDM Admin UI

1. Log in to the  Admin UI  and go to Infrastructure > Clusters.
2. Click the Add cluster button.
3. Select Elastic Kubernetes Service (instance profile) as the Cluster Type and set other  resource properties to configure how the StrongDM relay connects.

Add Your EKS Instance Profile Cluster in the StrongDM Admin UI

1. Log in to the  Admin UI  and go to Infrastructure > Clusters.
2. Click the Add cluster button.
3. Select Elastic Kubernetes Service (instance profile - User Impersonation) as the Cluster Type and set other  resource properties  to configure how the StrongDM relay connects.

Elastic Kubernetes Service Instance Profile - User Impersonation Cluster Setup in Admin UI

4. Click Create to save the resource.

The Admin UI updates and shows your new cluster in a green or yellow state. Green indicates a successful connection. If it is yellow, click the pencil icon to the right of the server to reopen the Connection Details screen. Then click Diagnostics to determine where the connection is failing.

Resource Properties

Configuration properties are visible when you add a Cluster Type or when you click to view the cluster’s settings. The following table describes the settings available for your EKS Instance Profile cluster.

Display name

Some Kubernetes management interfaces, such as Visual Studio Code, do not function properly with cluster names containing spaces. If you run into problems, please choose a Display Name without spaces.

Client credentials

When your users connect to this cluster, they have exactly the rights permitted by this AWS key pair. See  AWS documentation  for more information.

Server CA

How to get the Server CA from your kube config file:

1. Open the CLI and type cat ~/.kube/config to view the contents of the file.
2. In the file, under - cluster, copy the certificate-authority-data value. That is the server certificate in Base64 encoding.

  - cluster:

  certificate-authority-data: ... SERVER CERT BASE64 ...

Secret Store options

By default, server credentials are stored in StrongDM. However, these credentials can also be saved in a secrets management tool.

Non-StrongDM options appear in the Secret Store dropdown menu if they are created under  Network > Secret Stores . When you select another Secret Store type, its unique properties display. For more details, see  Configure Secret Store Integrations.

RBAC Configuration

You can now create RBAC Roles to grant permissions that will be applicable based on the StrongDM role(s) assigned to the StrongDM users.

Example of RBAC configuration to limit StrongDMole “developer” to a namespace “dev”

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: sdm-developer
rules:
- apiGroups:
  - ""
  resources:
  - "*"
  verbs:
  - get
  - list
  - watch
- apiGroups:
  - extensions
  resources:
  - "*"
  verbs:
  - get
  - list
  - watch
- apiGroups:
  - apps
  resources:
  - "*"
  verbs:
  - get
  - list
  - watch
- apiGroups:
  - "authorization.k8s.io"
  resources:
  - selfsubjectaccessreviews
  verbs:
  - create
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: sdm-developer
  namespace: dev
subjects:
- kind: Group
  name: developer # Name of the StrongDM role
  apiGroup: rbac.authorization.k8s.io
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: sdm-developer # Name of the cluster role you want that StrongDM role to have

After the role is created, you can check the access works as intended, for example:

$ kubectl auth can-i --as=* --as-group=developer get pods -n dev

yes

$ k auth can-i --as=* --as-group=developer get pods

no