Launching self-managed Amazon Linux nodes - Amazon EKS

Launching self-managed Amazon Linux nodes

This topic describes how you can launch an Auto Scaling group of Linux nodes that register with your Amazon EKS cluster. After the nodes join the cluster, you can deploy Kubernetes applications to them. You can also launch self-managed Amazon Linux 2 nodes with eksctl or the AWS Management Console.

Prerequisites

eksctl

Prerequisite

Version 0.97.0 or later of the eksctl command line tool installed on your computer or AWS CloudShell. To install or update eksctl, see Installing eksctl.

To launch self-managed Linux nodes using eksctl

  1. (Optional) If the AmazonEKS_CNI_Policy managed IAM policy is attached to your Amazon EKS node IAM role, we recommend assigning it to an IAM role that you associate to the Kubernetes aws-node service account instead. For more information, see Configuring the Amazon VPC CNI plugin to use IAM roles for service accounts.

  2. The following command creates a node group in an existing cluster. Replace every example-value with your own values. The nodes are created with the same Kubernetes version as the control plane, by default.

    For a complete list of supported values for --node-type, see amazon-eks-nodegroup.yaml on GitHub. Before choosing a value for --node-type, review Choosing an Amazon EC2 instance type.

    Replace my-key with the name of your Amazon EC2 key pair or public key. This key is used to SSH into your nodes after they launch. If you don't already have an Amazon EC2 key pair, you can create one in the AWS Management Console. For more information, see Amazon EC2 key pairs in the Amazon EC2 User Guide for Linux Instances.

    Create your node group with the following command.

    Important

    If you want to deploy a node group to AWS Outposts, AWS Wavelength, or AWS Local Zones subnets, there are additional considerations:

    eksctl create nodegroup \ --cluster my-cluster \ --name al-nodes \ --node-type t3.medium \ --nodes 3 \ --nodes-min 1 \ --nodes-max 4 \ --ssh-access \ --managed=false \ --ssh-public-key my-key

    To deploy a node group that allows your instance to assign a significantly higher number of IP addresses to pods, assign IP addresses to pods from a different CIDR block than that of the instance. Then, enable the containerd runtime you must deploy the node group using a config file. For more information, see Increase the amount of available IP addresses for your Amazon EC2 nodes, CNI custom networking, and Enable the containerd runtime bootstrap flag. For instructions on how to deploy a private node group without outbound internet access, see Private clusters. For a complete list of all available options and defaults, enter the following command.

    eksctl create nodegroup --help

    If nodes fail to join the cluster, then see Nodes fail to join cluster in the Troubleshooting guide.

    The output is as follows. Several lines are output while the nodes are created. One of the last lines of output is the following example line.

    [✔] created 1 nodegroup(s) in cluster "my-cluster"
  3. We recommend blocking pod access to IMDS if the following conditions are true:

    • You plan to assign IAM roles to all of your Kubernetes service accounts so that pods only have the minimum permissions that they need.

    • No pods in the cluster require access to the Amazon EC2 instance metadata service (IMDS) for other reasons, such as retrieving the current AWS Region.

    For more information, see Restrict access to the instance profile assigned to the worker node.

AWS Management Console

Step 1: To launch self-managed Linux nodes using the AWS Management Console

  1. Wait for your cluster status to show as ACTIVE. If you launch your nodes before the cluster is active, the nodes fail to register with the cluster and you will have to relaunch them.

  2. Download the latest version of the AWS CloudFormation template.

    curl -o amazon-eks-nodegroup.yaml https://s3.us-west-2.amazonaws.com/amazon-eks/cloudformation/2020-10-29/amazon-eks-nodegroup.yaml
  3. Open the AWS CloudFormation console at https://console.aws.amazon.com/cloudformation.

  4. Choose Create stack and then select With new resources (standard).

  5. For Specify template, select Upload a template file and then select Choose file. Select the amazon-eks-nodegroup.yaml file that you downloaded in step 2 and then select Next.

  6. On the Specify stack details page, enter the following parameters accordingly:

    • Stack name: Choose a stack name for your AWS CloudFormation stack. For example, you can call it cluster-name-nodes. The name can contain only alphanumeric characters (case-sensitive) and hyphens. It must start with an alphabetic character and can't be longer than 128 characters.

    • ClusterName: Enter the name that you used when you created your Amazon EKS cluster. This name must equal the cluster name or your nodes can't join the cluster.

    • ClusterControlPlaneSecurityGroup: Choose the SecurityGroups value from the AWS CloudFormation output that you generated when you created your VPC.

      The following steps show one operation to retrieve the applicable group.

      1. Open the Amazon EKS console at https://console.aws.amazon.com/eks/home#/clusters.

      2. Choose the name of the cluster.

      3. Choose the Configuration tab.

      4. Choose the Networking tab.

      5. Use the Additional Security Group value as a reference when selecting from the ClusterControlPlaneSecurityGroup dropdown list.

    • NodeGroupName: Enter a name for your node group. This name can be used later to identify the Auto Scaling node group that's created for your nodes.

    • NodeAutoScalingGroupMinSize: Enter the minimum number of nodes that your node Auto Scaling group can scale in to.

    • NodeAutoScalingGroupDesiredCapacity: Enter the desired number of nodes to scale to when your stack is created.

    • NodeAutoScalingGroupMaxSize: Enter the maximum number of nodes that your node Auto Scaling group can scale out to.

    • NodeInstanceType: Choose an instance type for your nodes. For more information, see Choosing an Amazon EC2 instance type.

    • NodeImageIdSSMParam: Pre-populated with the Amazon EC2 Systems Manager parameter of a recent Amazon EKS optimized Amazon Linux AMI ID for a Kubernetes version. To use a different Kubernetes minor version supported with Amazon EKS, replace 1.x with a different supported version. We recommend specifying the same Kubernetes version as your cluster.

      To use the Amazon EKS optimized accelerated AMI, replace amazon-linux-2 with amazon-linux-2-gpu. To use the Amazon EKS optimized Arm AMI, replace amazon-linux-2 with amazon-linux-2-arm64.

      Note

      The Amazon EKS node AMI is based on Amazon Linux 2. You can track security or privacy events for Amazon Linux 2 at the Amazon Linux Security Center or subscribe to the associated RSS feed. Security and privacy events include an overview of the issue, what packages are affected, and how to update your instances to correct the issue.

    • NodeImageId: (Optional) If you're using your own custom AMI (instead of the Amazon EKS optimized AMI), enter a node AMI ID for your AWS Region. If you specify a value here, it overrides any values in the NodeImageIdSSMParam field.

    • NodeVolumeSize: Specify a root volume size for your nodes, in GiB.

    • KeyName: Enter the name of an Amazon EC2 SSH key pair that you can use to connect using SSH into your nodes with after they launch. If you don't already have an Amazon EC2 key pair, you can create one in the AWS Management Console. For more information, see Amazon EC2 key pairs in the Amazon EC2 User Guide for Linux Instances.

      Note

      If you don't provide a key pair here, the AWS CloudFormation stack creation fails.

    • BootstrapArguments: Specify any optional arguments to pass to the node bootstrap script, such as extra kubelet arguments. For more information, view the bootstrap script usage information on GitHub. To deploy a node group that allows your instance to assign a significantly higher number of IP addresses to pods, assign IP addresses to pods from a different CIDR block than that of the instance. Then, enable the containerd runtime or deploy a private cluster without outbound internet access. For information about arguments to add, see Increase the amount of available IP addresses for your Amazon EC2 nodes, CNI custom networking, Enable the containerd runtime bootstrap flag, and Private clusters.

    • DisableIMDSv1: By default, each node supports the Instance Metadata Service Version 1 (IMDSv1) and IMDSv2. You can disable IMDSv1. To prevent future nodes and pods in the node group from using MDSv1, set DisableIMDSv1 to true. For more information about IMDS, see Configuring the instance metadata service. For more information about restricting access to it on your nodes, see Restrict access to the instance profile assigned to the worker node.

    • VpcId: Enter the ID for the VPC that you created.

    • Subnets: Choose the subnets that you created for your VPC. If you created your VPC using the steps that are described in Creating a VPC for your Amazon EKS cluster, specify only the private subnets within the VPC for your nodes to launch into.

      Important
      • If any of the subnets are public subnets, then they must have the automatic public IP address assignment setting enabled. If the setting isn't enabled for the public subnet, then any nodes that you deploy to that public subnet won't be assigned a public IP address and won't be able to communicate with the cluster or other AWS services. If the subnet was deployed before March 26, 2020 using either of the Amazon EKS AWS CloudFormation VPC templates, or by using eksctl, then automatic public IP address assignment is disabled for public subnets. For information about how to enable public IP address assignment for a subnet, see Modifying the Public IPv4 Addressing Attribute for Your Subnet. If the node is deployed to a private subnet, then it's able to communicate with the cluster and other AWS services through a NAT gateway.

      • If the subnets don't have internet access, make sure that you're aware of the considerations and extra steps in Private clusters.

      • If you're deploying the nodes in a 1.18 or earlier cluster, make sure that the subnets you select are tagged with the cluster name. Replace my-cluster with the name of your cluster. Then, run the following command to see a list of the subnets currently tagged with your cluster name.

        aws ec2 describe-subnets --filters Name=tag:kubernetes.io/cluster/my-cluster,Values=shared | grep SubnetId

        If the subnet you want to select isn't returned in the output from the previous command, manually add the tag to the subnet. For more information, see Subnet tagging.

      • If you select AWS Outposts, AWS Wavelength, or AWS Local Zones subnets, the subnets must not have been passed in when you created the cluster.

  7. Acknowledge that the stack might create IAM resources, and then choose Create stack.

  8. When your stack has finished creating, select it in the console and choose Outputs.

  9. Record the NodeInstanceRole for the node group that was created. You need this when you configure your Amazon EKS nodes.

Step 2: To enable nodes to join your cluster

Note

If you launched nodes inside a private VPC without outbound internet access, make sure to enable nodes to join your cluster from within the VPC.

  1. Download, edit, and apply the AWS IAM Authenticator configuration map.

    1. Download the configuration map using the following command.

      curl -o aws-auth-cm.yaml https://s3.us-west-2.amazonaws.com/amazon-eks/cloudformation/2020-10-29/aws-auth-cm.yaml
    2. Open the file with your text editor. Replace the ARN of instance role (not instance profile) snippet with the NodeInstanceRole value that you recorded in the previous procedure, and save the file.

      Important

      Don't modify any other lines in this file.

      apiVersion: v1 kind: ConfigMap metadata: name: aws-auth namespace: kube-system data: mapRoles: | - rolearn: ARN of instance role (not instance profile) username: system:node:{{EC2PrivateDNSName}} groups: - system:bootstrappers - system:nodes
    3. Apply the configuration. This command may take a few minutes to finish.

      kubectl apply -f aws-auth-cm.yaml
      Note

      If you receive any authorization or resource type errors, see Unauthorized or access denied (kubectl) in the troubleshooting section.

      If nodes fail to join the cluster, then see Nodes fail to join cluster in the Troubleshooting guide.

  2. Watch the status of your nodes and wait for them to reach the Ready status.

    kubectl get nodes --watch
  3. (GPU nodes only) If you chose a GPU instance type and the Amazon EKS optimized accelerated AMI, you must apply the NVIDIA device plugin for Kubernetes as a DaemonSet on your cluster with the following command.

    kubectl apply -f https://raw.githubusercontent.com/NVIDIA/k8s-device-plugin/v0.9.0/nvidia-device-plugin.yml
  4. (Optional) Deploy a sample application to test your cluster and Linux nodes.

  5. (Optional) If the AmazonEKS_CNI_Policy managed IAM policy (if you have an IPv4 cluster) or the AmazonEKS_CNI_IPv6_Policy (that you created yourself if you have an IPv6 cluster) is attached to your Amazon EKS node IAM role, we recommend assigning it to an IAM role that you associate to the Kubernetes aws-node service account instead. For more information, see Configuring the Amazon VPC CNI plugin to use IAM roles for service accounts.

  6. We recommend blocking pod access to IMDS if the following conditions are true:

    • You plan to assign IAM roles to all of your Kubernetes service accounts so that pods only have the minimum permissions that they need.

    • No pods in the cluster require access to the Amazon EC2 instance metadata service (IMDS) for other reasons, such as retrieving the current AWS Region.

    For more information, see Restrict access to the instance profile assigned to the worker node.