EKS: Cluster IAM Policies and Roles

This section guides a DKP user in creating IAM Policies and Instance Profiles that governs who has access to the cluster. The IAM Role is used by the cluster’s control plane and worker nodes using the provided AWS CloudFormation Stack specific to EKS. This CloudFormation Stack has additional permissions that are used to delegate access roles for other users.

Prerequisites from AWS:

The user you delegate from your role must have a minimum set of permissions, see User Roles and Instance Profiles page for AWS.
Create the Cluster IAM Policies in your AWS account.

EKS IAM Artifacts

Policies

controllers-eks.cluster-api-provider-aws.sigs.k8s.io - enumerates the Actions required by the workload cluster to create and modify EKS clusters in the user's AWS Account. It is attached to the existing control-plane.cluster-api-provider-aws.sigs.k8s.io role
eks-nodes.cluster-api-provider-aws.sigs.k8s.io - enumerates the Actions required by the EKS workload cluster’s worker machines. It is attached to the existing nodes.cluster-api-provider-aws.sigs.k8s.io

Roles

eks-controlplane.cluster-api-provider-aws.sigs.k8s.io - is the Role associated with EKS cluster control planes

NOTE: control-plane.cluster-api-provider-aws.sigs.k8s.io and nodes.cluster-api-provider-aws.sigs.k8s.io roles were created by Cluster IAM Policies and Roles in AWS.

Below is a CloudFormation stack that includes IAM policies and roles required to setup EKS Clusters:

CODE

AWSTemplateFormatVersion: 2010-09-09
Parameters:
  existingControlPlaneRole:
    Type: CommaDelimitedList
    Description: 'Names of existing Control Plane Role you want to add to the newly created EKS Managed Policy for AWS cluster API controllers'
    Default: control-plane.cluster-api-provider-aws.sigs.k8s.io
  existingNodeRole:
    Type: CommaDelimitedList
    Description: 'ARN of the Nodes Managed Policy to add to the role for nodes'
    Default: nodes.cluster-api-provider-aws.sigs.k8s.io
Resources:
  AWSIAMManagedPolicyControllersEKS:
    Properties:
      Description: For the Kubernetes Cluster API Provider AWS Controllers
      ManagedPolicyName: controllers-eks.cluster-api-provider-aws.sigs.k8s.io
      PolicyDocument:
        Statement:
          - Action:
              - 'ssm:GetParameter'
            Effect: Allow
            Resource:
              - 'arn:*:ssm:*:*:parameter/aws/service/eks/optimized-ami/*'
          - Action:
              - 'iam:CreateServiceLinkedRole'
            Condition:
              StringLike:
                'iam:AWSServiceName': eks.amazonaws.com
            Effect: Allow
            Resource:
              - >-
                arn:*:iam::*:role/aws-service-role/eks.amazonaws.com/AWSServiceRoleForAmazonEKS
          - Action:
              - 'iam:CreateServiceLinkedRole'
            Condition:
              StringLike:
                'iam:AWSServiceName': eks-nodegroup.amazonaws.com
            Effect: Allow
            Resource:
              - >-
                arn:*:iam::*:role/aws-service-role/eks-nodegroup.amazonaws.com/AWSServiceRoleForAmazonEKSNodegroup
          - Action:
              - 'iam:CreateServiceLinkedRole'
            Condition:
              StringLike:
                'iam:AWSServiceName': eks-fargate.amazonaws.com
            Effect: Allow
            Resource:
              - >-
                arn:aws:iam::*:role/aws-service-role/eks-fargate-pods.amazonaws.com/AWSServiceRoleForAmazonEKSForFargate
          - Action:
              - 'iam:GetRole'
              - 'iam:ListAttachedRolePolicies'
            Effect: Allow
            Resource:
              - 'arn:*:iam::*:role/*'
          - Action:
              - 'iam:GetPolicy'
            Effect: Allow
            Resource:
              - 'arn:aws:iam::aws:policy/AmazonEKSClusterPolicy'
          - Action:
              - 'eks:DescribeCluster'
              - 'eks:ListClusters'
              - 'eks:CreateCluster'
              - 'eks:TagResource'
              - 'eks:UpdateClusterVersion'
              - 'eks:DeleteCluster'
              - 'eks:UpdateClusterConfig'
              - 'eks:UntagResource'
              - 'eks:UpdateNodegroupVersion'
              - 'eks:DescribeNodegroup'
              - 'eks:DeleteNodegroup'
              - 'eks:UpdateNodegroupConfig'
              - 'eks:CreateNodegroup'
              - 'eks:AssociateEncryptionConfig'
              - 'eks:ListIdentityProviderConfigs'
              - 'eks:AssociateIdentityProviderConfig'
              - 'eks:DescribeIdentityProviderConfig'
              - 'eks:DisassociateIdentityProviderConfig'
            Effect: Allow
            Resource:
              - 'arn:*:eks:*:*:cluster/*'
              - 'arn:*:eks:*:*:nodegroup/*/*/*'
          - Action:
              - 'ec2:AssociateVpcCidrBlock'
              - 'ec2:DisassociateVpcCidrBlock'
              - 'eks:ListAddons'
              - 'eks:CreateAddon'
              - 'eks:DescribeAddonVersions'
              - 'eks:DescribeAddon'
              - 'eks:DeleteAddon'
              - 'eks:UpdateAddon'
              - 'eks:TagResource'
              - 'eks:DescribeFargateProfile'
              - 'eks:CreateFargateProfile'
              - 'eks:DeleteFargateProfile'
            Effect: Allow
            Resource:
              - '*'
          - Action:
              - 'iam:PassRole'
            Condition:
              StringEquals:
                'iam:PassedToService': eks.amazonaws.com
            Effect: Allow
            Resource:
              - '*'
          - Action:
              - 'kms:CreateGrant'
              - 'kms:DescribeKey'
            Condition:
              'ForAnyValue:StringLike':
                'kms:ResourceAliases': alias/cluster-api-provider-aws-*
            Effect: Allow
            Resource:
              - '*'
        Version: 2012-10-17
      Roles: !Ref existingControlPlaneRole
    Type: 'AWS::IAM::ManagedPolicy'
  AWSIAMManagedEKSNodesPolicy:
    Properties:
      Description: Additional Policies to nodes role to work for EKS
      ManagedPolicyName: eks-nodes.cluster-api-provider-aws.sigs.k8s.io
      PolicyDocument:
        Statement:
          - Action:
              - "ec2:AssignPrivateIpAddresses"
              - "ec2:AttachNetworkInterface"
              - "ec2:CreateNetworkInterface"
              - "ec2:DeleteNetworkInterface"
              - "ec2:DescribeInstances"
              - "ec2:DescribeTags"
              - "ec2:DescribeNetworkInterfaces"
              - "ec2:DescribeInstanceTypes"
              - "ec2:DetachNetworkInterface"
              - "ec2:ModifyNetworkInterfaceAttribute"
              - "ec2:UnassignPrivateIpAddresses"
            Effect: Allow
            Resource:
              - '*'
          - Action:
              - ec2:CreateTags
            Effect: Allow
            Resource:
              - arn:aws:ec2:*:*:network-interface/*
          - Action:
              - "ec2:DescribeInstances"
              - "ec2:DescribeInstanceTypes"
              - "ec2:DescribeRouteTables"
              - "ec2:DescribeSecurityGroups"
              - "ec2:DescribeSubnets"
              - "ec2:DescribeVolumes"
              - "ec2:DescribeVolumesModifications"
              - "ec2:DescribeVpcs"
              - "eks:DescribeCluster"
            Effect: Allow
            Resource:
              - '*'
        Version: 2012-10-17
      Roles: !Ref existingNodeRole
    Type: 'AWS::IAM::ManagedPolicy'
  AWSIAMRoleEKSControlPlane:
    Properties:
      AssumeRolePolicyDocument:
        Statement:
          - Action:
              - 'sts:AssumeRole'
            Effect: Allow
            Principal:
              Service:
                - eks.amazonaws.com
        Version: 2012-10-17
      ManagedPolicyArns:
        - 'arn:aws:iam::aws:policy/AmazonEKSClusterPolicy'
      RoleName: eks-controlplane.cluster-api-provider-aws.sigs.k8s.io
    Type: 'AWS::IAM::Role'

To create the resources in the CloudFormation stack, copy the contents above into a file and execute the following command after replacing MYFILENAME.yaml and MYSTACKNAME with the intended values:

CODE

 aws cloudformation create-stack --template-body=file://MYFILENAME.yaml --stack-name=MYSTACKNAME --capabilities  CAPABILITY_NAMED_IAM

Add EKS CSI Policy

AWS CloudFormation does not support attaching an existing IAM Policy to an existing IAM Role. Add the necessary IAM policy to your worker instance profile using the aws CLI:

CODE

aws iam attach-role-policy --role-name nodes.cluster-api-provider-aws.sigs.k8s.io --policy-arn arn:aws:iam::aws:policy/service-role/AmazonEBSCSIDriverPolicy

Next Step:

EKS: Create an Image