Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

Customize Amazon EKS launch templates

Amazon Batch on Amazon EKS supports launch templates. There are constraints on what your launch template can do.

Add kubelet extra arguments

Amazon Batch supports adding extra arguments to the kubelet command. For the list of supported parameters, see kubelet in the Kubernetes documentation. In the following example for EKS AL2 AMIs, --node-labels mylabel=helloworld is added to the kubelet command line.

MIME-Version: 1.0
      Content-Type: multipart/mixed; boundary="==MYBOUNDARY=="

      --==MYBOUNDARY==
      Content-Type: text/x-shellscript; charset="us-ascii"

      #!/bin/bash
      mkdir -p /etc/aws-batch

      echo AWS_BATCH_KUBELET_EXTRA_ARGS=\"--node-labels mylabel=helloworld\" >> /etc/aws-batch/batch.config

      --==MYBOUNDARY==--

For EKS AL2023 AMIs the file format is YAML. For the list of supported parameters, see NodeConfigSpec in the Kubernetes documentation. In the following example for EKS AL2023 AMIs, --node-labels mylabel=helloworld is added to the kubelet command line.

MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="==MYBOUNDARY=="

--==MYBOUNDARY==
Content-Type: application/node.eks.aws

apiVersion: node.eks.aws/v1alpha1
kind: NodeConfig
spec:
  kubelet:
    flags:
    - --node-labels=mylabel=helloworld

--==MYBOUNDARY==--

Configure the container runtime

You can use the Amazon Batch CONTAINER_RUNTIME environment variable to configure the container runtime on a managed node. The following example sets the container runtime to containerd when bootstrap.sh runs. For more information, see containerd in the Kubernetes documentation.

If you are using an optimized EKS_AL2023 or EKS_AL2023_NVIDIA AMI you do not need to specify the container runtime as only containerd is supported.

MIME-Version: 1.0
      Content-Type: multipart/mixed; boundary="==MYBOUNDARY=="

      --==MYBOUNDARY==
      Content-Type: text/x-shellscript; charset="us-ascii"

      #!/bin/bash
      mkdir -p /etc/aws-batch

      echo CONTAINER_RUNTIME=containerd >> /etc/aws-batch/batch.config

      --==MYBOUNDARY==--

Mount an Amazon EFS volume

You can use launch templates to mount volumes to the node. In the following example, the cloud-config packages and runcmd settings are used. For more information, see Cloud config examples in the cloud-init documentation.

MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="==MYBOUNDARY=="

--==MYBOUNDARY==
Content-Type: text/cloud-config; charset="us-ascii"

packages:
- amazon-efs-utils

runcmd:
- file_system_id_01=fs-abcdef123
- efs_directory=/mnt/efs

- mkdir -p ${efs_directory}
- echo "${file_system_id_01}:/ ${efs_directory} efs _netdev,noresvport,tls,iam 0 0" >> /etc/fstab
- mount -t efs -o tls ${file_system_id_01}:/ ${efs_directory}

--==MYBOUNDARY==--

To use this volume in the job, it must be added in the eksProperties parameter to RegisterJobDefinition. The following example is a large portion of the job definition.

{
    "jobDefinitionName": "MyJobOnEks_EFS",
    "type": "container",
    "eksProperties": {
        "podProperties": {
            "containers": [
                {
                    "image": "public.ecr.aws/amazonlinux/amazonlinux:2",
                    "command": ["ls", "-la", "/efs"],
                    "resources": {
                        "limits": {
                            "cpu": "1",
                            "memory": "1024Mi"
                        }
                    },
                    "volumeMounts": [
                        {
                            "name": "efs-volume",
                            "mountPath": "/efs"
                        }
                    ]
                }
            ],
            "volumes": [
                {
                    "name": "efs-volume",
                    "hostPath": {
                        "path": "/mnt/efs"
                    }
                }
            ]
        }
    }
}

In the node, the Amazon EFS volume is mounted in the /mnt/efs directory. In the container for the Amazon EKS job, the volume is mounted in the /efs directory.

IPv6 support

Amazon Batch supports Amazon EKS clusters that have IPv6 addresses. No customizations are required for Amazon Batch support. However, before you begin, we recommend that you review the considerations and conditions that are outlined in Assigning IPv6 addresses to pods and services in the Amazon EKS User Guide.