Red Hat OpenShift - Windows compute nodes
Wed, 06 Dec 2023 10:35:35 -0000
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Red Hat OpenShift - Windows compute nodes
Red Hat® OpenShift® Container Platform is an industry-leading Kubernetes platform that enables a cloud-native development environment together with a cloud operations experience, giving you the ability to choose where you build, deploy, and run applications, all through a consistent interface. Powered by the open source-based OpenShift Kubernetes Engine, Red Hat OpenShift provides cluster management, platform services for managing workloads, application services for building cloud-native applications, and developer services for enhancing developer productivity.
Support for Windows containers
OpenShift Container Platform enables you to host and run Windows-based workloads on Windows compute nodes alongside the traditional Linux workloads that are hosted on Red Hat Enterprise Linux CoreOS (RHCOS) or Red Hat Enterprise Linux compute nodes. For more information, see Red Hat OpenShift support for Windows Containers.
As a prerequisite for installing Widows workloads, the Windows Machine Config Operator must be installed on a cluster that is configured with hybrid networking using OVN-Kubernetes. The operator configures Windows compute nodes and orchestrates the process of deploying and managing Windows workloads on a cluster.
Open Virtual Network (OVN) is the only supported networking configuration for installing Windows compute nodes. OpenShift Container Platform uses the OVN-Kubernetes network plug-in as its default network provider. You can configure the OpenShift Networking OVN-Kubernetes network plug-in to enable Linux and Windows nodes to host Linux and Windows workloads respectively. For more information, see About the OVN-Kubernetes network plugin.
Adding a Windows node
You will need an already installed cluster, built using the IPI installation method or the Assisted Installer. For more information about deploying an OpenShift cluster on Dell bare-metal servers, see the Red Hat OpenShift Container Platform 4.12 on Dell Infrastructure Implementation Guide.
Create a custom manifest file to configure the Hybrid OVN-Kubernetes network during the cluster deployment by running the following commands:
cat cluster-network-03-config.yml
apiVersion: operator.openshift.io/v1
kind: Network
metadata:
name: cluster
spec:
defaultNetwork:
ovnKubernetesConfig:
hybridOverlayConfig:
hybridClusterNetwork:
- cidr: 10.132.0.0/14
hostPrefix: 23
To add the server to the cluster as a worker node, you need bare-metal server with a Windows operating system. For the supported Windows versions, see Red Hat OpenShift 4.13 support for Windows Containers release notes.
- Open ports 22 and 10250 for SSH and for log collection on the Windows server.
- Create an administrator user. The administrator user’s private key is used in the secret as an authorized SSH key and to enable password-less authentication to the Windows server.
- Install the Windows Machine Config Operator on the cluster.
- In the openshift-windows-machine-config-operator namespace, create the secret from the administrator user’s private key.
- Describe the IPv4 or DNS address of the Windows instance and the administrator user in the configmap.
The WMCO operator scans for the secret created during boot, and creates another user data secret with the data that is required to interact with the Windows server using the SSH protocol. After the SSH connection is established, the operator starts processing the Windows servers that are listed in the configmap and begins to transfer files and configure the nodes. The CSRs that are generated are auto-approved, and the Windows instance is added to the cluster.
Environment overview
OpenShift Container platform is hosted on Dell PowerEdge R650 servers, enabling hybrid networking with OVN-Kubernetes. The Dell-validated environment consisted of three compute nodes. The validation team added a Windows instance to the cluster as a fourth node. The following table shows the cluster version information:
OpenShift cluster version | 4.13.21 |
Kubernetes version | 1.26.9 |
WCMO operator version | 8.1.0+0.1699557880.p |
Windows instance version | Windows server 2019 (Version 1809) |
References
Configuring hybrid networking - OVN-Kubernetes network plugin