Launching self-managed Amazon Linux nodes - Amazon EKS

Launching self-managed Amazon Linux nodes

This topic describes how you can launch Auto Scaling groups 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. If you need to launch nodes on AWS Outposts, see Launching self-managed Amazon Linux nodes on an Outpost.

Prerequisites

eksctl

Prerequisite

Version 0.112.0 or later of the eksctl command line tool installed on your device or AWS CloudShell. To install or update eksctl, see Installing or updating 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 for Kubernetes to use IAM roles for service accounts.

  2. The following command creates a node group in an existing cluster. Replace al-nodes with a name for your node group. The name can contain only alphanumeric characters (case-sensitive) and hyphens. It must start with an alphabetic character and can't be longer than 100 characters.. Replace my-cluster with the name of your cluster. The name can contain only alphanumeric characters (case-sensitive) and hyphens. It must start with an alphabetic character and can't be longer than 100 characters.. Replace the remaining example value with your own values. The nodes are created with the same Kubernetes version as the control plane, by default.

    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, Wavelength, or Local Zone 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:

    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 example 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. 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
  2. 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.

  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, and then choose Next:

    • Stack name: Choose a stack name for your AWS CloudFormation stack. For example, you can call it my-cluster-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 100 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 Networking tab.

      4. Use the Additional security groups 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:

    • 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. You can see which subnets are private by opening each subnet link from the Networking tab of your cluster.

      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 cluster requirements.

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

  7. Select your desired choices on the Configure stack options page, and then choose Next.

  8. Select the check box to the left of I acknowledge that AWS CloudFormation might create IAM resources., and then choose Create stack.

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

  10. 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. In the aws-auth-cm.yaml file, set the rolearn to the value that you recorded in the previous procedure. You can do this with a text editor, or by replacing my-node-instance-role and running the following command:

      sed -i.bak -e 's|<ARN of instance role (not instance profile)>|my-node-instance-role|' aws-auth-cm.yaml
    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

    Enter Ctrl+C to return to a shell prompt.

  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 for Kubernetes 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.