Auto Mode

About Auto Mode

Amazon EKS Auto Mode automates Kubernetes cluster management by handling tasks such as node provisioning, scaling, and upgrades. It eliminates manual node group configuration, ensuring clusters are cost-efficient, secure, and optimized for performance.

For more details, visit Amazon EKS Auto Mode.

Why EKS Auto Mode?

EKS Auto Mode simplifies operations by leveraging AWS best practices for resource utilization and security. It uses Karpenter for automatic node provisioning and scaling, while managing infrastructure tasks like node scaling and automatic upgrades every 21 days.

Auto Mode can be enabled on Day 0 during new cluster creation, where it provisions and scales nodes automatically. For Day 2, existing clusters can be converted to Auto Mode, retaining previously configured node groups. Users can decide to keep or remove original node groups based on requirements.

For a deeper dive into how EKS Auto Mode works, read this AWS blog.

Did you know ?

EKS Auto Mode can be managed through various methods:

• API
• UI
• CLI
• Terraform
• GitOps

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Pre-requisite

The following permissions are required for enabling the EKS Auto Mode, divided into ClusterRole and NodeRole permissions.

ClusterRole Permissions:

• AmazonEKSComputePolicy
• AmazonEKSBlockStoragePolicy
• AmazonEKSLoadBalancingPolicy
• AmazonEKSNetworkingPolicy
• AmazonEKSClusterPolicy

NodeRole Permissions:

• AmazonEKSWorkerNodeMinimalPolicy
• AmazonEC2ContainerRegistryPullOnly

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Day-0 Support

On Day 0, EKS Auto Mode can be enabled during cluster creation, allowing automatic node provisioning and scaling with minimal configuration. This simplifies cluster setup, ensuring optimal resource management aligned with AWS best practices.

Enable Auto Node via UI

• During cluster creation, after selecting the General settings, enable Use EKS Auto Mode under Cluster settings
• Select the Node Pool type from the drop-down: either general-purpose or system or both
• Provide the Node Role ARN. If no Node Role ARN is provided, default policies will be automatically applied to the nodes

Enable Auto Node via RCTL

To enable auto node via RCTL, add the autoModeConfig parameters to the EKS Cluster Config Spec as given in the below example

autoModeConfig:
  enabled: true
  nodeRoleARN: arn:aws:iam::200143372387:role/rafay-demouser1-auto-01-cluster-AutoModeNodeRole-65AagDXNwCps
  nodePools:
  - general-purpose
  - system

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Day-2 Support

Users have the ability to enable EKS Auto Mode post-cluster creation if it was not initially enabled. As part of Day 2 support, users can convert an existing cluster to use the EKS Auto Mode configuration. Once Auto Mode is enabled, users can modify cluster settings, update scaling configurations, and manage node upgrades. It is also possible to disable Auto Mode and revert to manual node management when needed.

To enable auto mode,

• Select the desired cluster from the Clusters page
• Click on the settings gear icon and select Enable/Disable Auto Mode

• Enable Use EKS Auto Mode and choose the Node Pool(s): either system, general-purpose, or both
• Optionally, enter the Node Role ARN and click Save

A message appears stating "EKS Auto Mode updated successfully.

EKS Auto on Existing Clusters

Before enabling EKS Auto Mode on an existing cluster, ensure you're running Karpenter v1.1 or later to avoid API conflicts. For detailed prerequisites and migration steps, see the AWS documentation.

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