EKS managed nodegroups - Eksctl User Guide
Creating managed nodegroupsUpgrading managed nodegroupsHandling parallel upgrades for nodesUpdating managed nodegroupsNodegroup Health issuesManaging LabelsScaling Managed NodegroupsFurther information

EKS managed nodegroups

Amazon EKS managed nodegroups is a feature that automates the provisioning and lifecycle management of nodes (EC2 instances) for Amazon EKS Kubernetes clusters. Customers can provision optimized groups of nodes for their clusters and EKS will keep their nodes up to date with the latest Kubernetes and host OS versions.

An EKS managed node group is an autoscaling group and associated EC2 instances that are managed by AWS for an Amazon EKS cluster. Each node group uses the Amazon EKS-optimized Amazon Linux 2 AMI. Amazon EKS makes it easy to apply bug fixes and security patches to nodes, as well as update them to the latest Kubernetes versions. Each node group launches an autoscaling group for your cluster, which can span multiple AWS VPC availability zones and subnets for high-availability.

NEW Launch Template support for managed nodegroups

Note

The term "unmanaged nodegroups" has been used to refer to nodegroups that eksctl has supported since the beginning (represented via the nodeGroups field). The ClusterConfig file continues to use the nodeGroups field for defining unmanaged nodegroups, and managed nodegroups are defined with the managedNodeGroups field.

Creating managed nodegroups

$ eksctl create nodegroup

New clusters

To create a new cluster with a managed nodegroup, run

eksctl create cluster

To create multiple managed nodegroups and have more control over the configuration, a config file can be used.

Note

Managed nodegroups do not have complete feature parity with unmanaged nodegroups.

# cluster.yaml
# A cluster with two managed nodegroups
---
apiVersion: eksctl.io/v1alpha5
kind: ClusterConfig

metadata:
  name: managed-cluster
  region: us-west-2

managedNodeGroups:
  - name: managed-ng-1
    minSize: 2
    maxSize: 4
    desiredCapacity: 3
    volumeSize: 20
    ssh:
      allow: true
      publicKeyPath: ~/.ssh/ec2_id_rsa.pub
      # new feature for restricting SSH access to certain AWS security group IDs
      sourceSecurityGroupIds: ["sg-00241fbb12c607007"]
    labels: {role: worker}
    tags:
      nodegroup-role: worker
    iam:
      withAddonPolicies:
        externalDNS: true
        certManager: true

  - name: managed-ng-2
    instanceType: t2.large
    minSize: 2
    maxSize: 3

Another example of a config file for creating a managed nodegroup can be found here.

It’s possible to have a cluster with both managed and unmanaged nodegroups. Unmanaged nodegroups do not show up in the AWS EKS console but eksctl get nodegroup will list both types of nodegroups.

# cluster.yaml
# A cluster with an unmanaged nodegroup and two managed nodegroups.
---
apiVersion: eksctl.io/v1alpha5
kind: ClusterConfig

metadata:
  name: managed-cluster
  region: us-west-2

nodeGroups:
  - name: ng-1
    minSize: 2

managedNodeGroups:
  - name: managed-ng-1
    minSize: 2
    maxSize: 4
    desiredCapacity: 3
    volumeSize: 20
    ssh:
      allow: true
      publicKeyPath: ~/.ssh/ec2_id_rsa.pub
      # new feature for restricting SSH access to certain AWS security group IDs
      sourceSecurityGroupIds: ["sg-00241fbb12c607007"]
    labels: {role: worker}
    tags:
      nodegroup-role: worker
    iam:
      withAddonPolicies:
        externalDNS: true
        certManager: true

  - name: managed-ng-2
    instanceType: t2.large
    privateNetworking: true
    minSize: 2
    maxSize: 3

NEW Support for custom AMI, security groups, instancePrefix, instanceName, ebsOptimized, volumeType, volumeName, volumeEncrypted, volumeKmsKeyID, volumeIOPS, maxPodsPerNode, preBootstrapCommands, overrideBootstrapCommand, and disableIMDSv1 

# cluster.yaml
# A cluster with a managed nodegroup with customization.
---
apiVersion: eksctl.io/v1alpha5
kind: ClusterConfig

metadata:
  name: managed-cluster
  region: us-west-2

managedNodeGroups:
  - name: custom-ng
    ami: ami-0e124de4755b2734d
    securityGroups:
      attachIDs: ["sg-1234"]
    maxPodsPerNode: 80
    ssh:
      allow: true
    volumeSize: 100
    volumeName: /dev/xvda
    volumeEncrypted: true
    # defaults to true, which enforces the use of IMDSv2 tokens
    disableIMDSv1: false
    overrideBootstrapCommand: |
      #!/bin/bash
      /etc/eks/bootstrap.sh managed-cluster --kubelet-extra-args '--node-labels=eks.amazonaws.com/nodegroup=custom-ng,eks.amazonaws.com/nodegroup-image=ami-0e124de4755b2734d'

If you are requesting an instance type that is only available in one zone (and the eksctl config requires specification of two) make sure to add the availability zone to your node group request:

# cluster.yaml
# A cluster with a managed nodegroup with "availabilityZones"
---

apiVersion: eksctl.io/v1alpha5
kind: ClusterConfig

metadata:
  name: flux-cluster
  region: us-east-2
  version: "1.23"

availabilityZones: ["us-east-2b", "us-east-2c"]
managedNodeGroups:
  - name: workers
    instanceType: hpc6a.48xlarge
    minSize: 64
    maxSize: 64
    labels: { "fluxoperator": "true" }
    availabilityZones: ["us-east-2b"]
    efaEnabled: true
    placement:
      groupName: eks-efa-testing

This can be true for instance types like the Hpc6 family that are only available in one zone.

Existing clusters

eksctl create nodegroup --managed

Tip : if you are using a ClusterConfig file to describe your whole cluster, describe your new managed node group in the managedNodeGroups field and run:

eksctl create nodegroup --config-file=YOUR_CLUSTER.yaml

Upgrading managed nodegroups

You can update a nodegroup to the latest EKS-optimized AMI release version for the AMI type you are using at any time.

If your nodegroup is the same Kubernetes version as the cluster, you can update to the latest AMI release version for that Kubernetes version of the AMI type you are using. If your nodegroup is the previous Kubernetes version from the cluster’s Kubernetes version, you can update the nodegroup to the latest AMI release version that matches the nodegroup’s Kubernetes version, or update to the latest AMI release version that matches the clusters Kubernetes version. You cannot roll back a nodegroup to an earlier Kubernetes version.

To upgrade a managed nodegroup to the latest AMI release version:

eksctl upgrade nodegroup --name=managed-ng-1 --cluster=managed-cluster

The nodegroup can be upgraded to the latest AMI release for a specified Kubernetes version using:

eksctl upgrade nodegroup --name=managed-ng-1 --cluster=managed-cluster --kubernetes-version=<kubernetes-version>

To upgrade to a specific AMI release version instead of the latest version, pass --release-version:

eksctl upgrade nodegroup --name=managed-ng-1 --cluster=managed-cluster --release-version=1.19.6-20210310
Note

If the managed nodes are deployed using custom AMIs, the following workflow must be followed in order to deploy a new version of the custom AMI.

  • initial deployment of the nodegroup must be done using a launch template. e.g.

    managedNodeGroups:
  - name: launch-template-ng
    launchTemplate:
      id: lt-1234
      version: "2" #optional (uses the default version of the launch template if unspecified)

  • create a new version of the custom AMI (using AWS EKS console).

  • create a new launch template version with the new AMI ID (using AWS EKS console).

  • upgrade the nodes to the new version of the launch template. e.g.

    eksctl upgrade nodegroup --name nodegroup-name --cluster cluster-name --launch-template-version new-template-version

Handling parallel upgrades for nodes

Multiple managed nodes can be upgraded simultaneously. To configure parallel upgrades, define the updateConfig of a nodegroup when creating the nodegroup. An example updateConfig can be found here.

To avoid any downtime to your workloads due to upgrading multiple nodes at once, you can limit the number of nodes that can become unavailable during an upgrade by specifying this in the maxUnavailable field of an updateConfig. Alternatively, use maxUnavailablePercentage, which defines the maximum number of unavailable nodes as a percentage of the total number of nodes.

Note that maxUnavailable cannot be higher than maxSize. Also, maxUnavailable and maxUnavailablePercentage cannot be used simultaneously.

This feature is only available for managed nodes.

Updating managed nodegroups

eksctl allows updating the UpdateConfig section of a managed nodegroup. This section defines two fields. MaxUnavailable and MaxUnavailablePercentage. Your nodegroups are unaffected during the update, thus downtime shouldn’t be expected.

The command update nodegroup should be used with a config file using the --config-file flag. The nodegroup should contain an nodeGroup.updateConfig section. More information can be found here.

Nodegroup Health issues

EKS Managed Nodegroups automatically checks the configuration of your nodegroup and nodes for health issues and reports them through the EKS API and console. To view health issues for a nodegroup:

eksctl utils nodegroup-health --name=managed-ng-1 --cluster=managed-cluster

Managing Labels

EKS Managed Nodegroups supports attaching labels that are applied to the Kubernetes nodes in the nodegroup. This is specified via the labels field in eksctl during cluster or nodegroup creation.

To set new labels or updating existing labels on a nodegroup:

eksctl set labels --cluster managed-cluster --nodegroup managed-ng-1 --labels kubernetes.io/managed-by=eks,kubernetes.io/role=worker

To unset or remove labels from a nodegroup:

eksctl unset labels --cluster managed-cluster --nodegroup managed-ng-1 --labels kubernetes.io/managed-by,kubernetes.io/role

To view all labels set on a nodegroup:

eksctl get labels --cluster managed-cluster --nodegroup managed-ng-1

Scaling Managed Nodegroups

eksctl scale nodegroup also supports managed nodegroups. The syntax for scaling a managed or unmanaged nodegroup is the same.

eksctl scale nodegroup --name=managed-ng-1 --cluster=managed-cluster --nodes=4 --nodes-min=3 --nodes-max=5

Further information