Windows Worker Nodes¶
From version 1.14, Amazon EKS supports Windows Nodes that allow running Windows containers.
In addition to having Windows nodes, a Linux node in the cluster is required to run the VPC resource controller and CoreDNS, as Microsoft doesn't support host-networking mode yet. Thus, a Windows EKS cluster will be a mixed-mode cluster containing Windows nodes and at least one Linux node.
The Linux nodes are critical to the functioning of the cluster, and thus, for a production-grade cluster, it's recommended to have at least two t2.large Linux nodes for HA.
eksctl provides a flag to install the VPC resource controller as part of cluster creation, and a command to install it after a cluster has been created.
Creating a new Windows cluster¶
The config file syntax allows creating a fully-functioning Windows cluster in a single command:
# cluster.yaml
# An example of ClusterConfig containing Windows and Linux node groups to support Windows workloads
---
apiVersion: eksctl.io/v1alpha5
kind: ClusterConfig
metadata:
name: windows-cluster
region: us-west-2
nodeGroups:
- name: windows-ng
amiFamily: WindowsServer2019FullContainer
minSize: 2
maxSize: 3
- name: linux-ng
instanceType: t2.large
minSize: 2
maxSize: 3
eksctl create cluster -f cluster.yaml --install-vpc-controllers
To create a new cluster without using a config file, issue the following commands:
eksctl create cluster --name=windows-cluster --node-ami-family=WindowsServer2019CoreContainer
eksctl create nodegroup --cluster=windows-cluster --node-ami-family=AmazonLinux2 --nodes-min=2 --node-type=t2.large
eksctl utils install-vpc-controllers --cluster=windows-cluster --approve
Adding Windows support to an existing Linux cluster¶
To enable running Windows workloads on an existing cluster with Linux nodes (AmazonLinux2 AMI family), you need to add a Windows node group and install the Windows VPC controller:
eksctl create nodegroup --cluster=existing-cluster --node-ami-family=WindowsServer2019CoreContainer
eksctl utils install-vpc-controllers --cluster=existing-cluster --approve
To ensure workloads are scheduled on the right OS, they must have a nodeSelector targeting the OS it must run on:
# Targeting Windows
nodeSelector:
beta.kubernetes.io/os: windows
beta.kubernetes.io/arch: amd64
# Targeting Linux
nodeSelector:
beta.kubernetes.io/os: linux
beta.kubernetes.io/arch: amd64