Windows Container Support for Red Hat OpenShift release notes

The release notes for Red Hat OpenShift for Windows Containers tracks the development of the WMCO, which provides all Windows container workload capabilities in OKD.

You must have a subscription to receive support for the Red Hat WMCO. Deploying Windows container workloads in production clusters is not supported without a subscription. If you do not have a subscription, you can use the community WMCO, a distribution that lacks official support. Request support through the Red Hat Customer Portal.

Issued: 2021-09-21

The WMCO 3.1.0 is now available with bug fixes and a new feature. The components of the WMCO were released in .

Using Bring-Your-Own-Host (BYOH) Windows instances

You can now add an existing Windows instance to an OKD cluster as a compute node. This requires creating a config map in the WMCO namespace.

BYOH Windows instances are supported with installer-provisioned infrastructure for the following platforms:

• Amazon Web Services (AWS)

• Microsoft Azure

BYOH Windows instances are supported with user-provisioned infrastructure, only when the field is set in the install-config.yaml file, for the following platforms:

• VMware vSphere

• bare metal

For more information on how to configure BYOH Windows instances, see .

Bug fixes

• For clusters installed on VMware vSphere, the WMCO ignored the Deleting phase notification event, leaving incorrect node information in the metrics endpoint. This resulted in an invalid mapping for the Prometheus metrics endpoint. This bug has been fixed; the WMCO now recognizes the Deleting phase notification event and maps the Prometheus metrics endpoint appropriately. ()

Known issues

• When installing a BYOH Windows instance using a DNS name entry in the config map, the WMCO configures the instance twice before marking it as a Ready node. This will be fixed in a future release of the WMCO. ()

This release of the WMCO provides bug fixes and enhancements for running Windows compute nodes in an OKD cluster. The components of the WMCO 3.0.0 were released in RHSA-2021:3001.

The following information details the supported platform versions, Windows Server versions, and networking configurations for the Windows Machine Config Operator. See the vSphere documentation for any information that is relevant to only that platform.

Supported platforms based on OKD and WMCO versions

1. This installation type is only supported when the field is set in the install-config.yaml file during cluster installation.

Supported Windows Server versions

The following table lists the supported based on the applicable platform. Any unlisted Windows Server version is not supported and will cause errors. To prevent these errors, only use the appropriate version according to the platform in use.

Supported networking

Hybrid networking with OVN-Kubernetes is the only supported networking configuration. See the additional resources below for more information on this functionality. The following tables outline the type of networking configuration and Windows Server versions to use based on your platform. You must specify the network configuration when you install the cluster. Be aware that OpenShift SDN networking is the default network for OKD clusters. However, OpenShift SDN is not supported by WMCO.

Supported installation method

The installer-provisioned infrastructure installation method is the only supported installation method. This is consistent across all supported platforms. The user-provisioned infrastructure installation method is Tech Preview for all supported platforms.

Version 3.x of the WMCO is only compatible with OKD 4.8.

This release adds the following new features and improvements.

Clarified limits on custom VXLAN port selection

Users must not select a custom VXLAN port when using the latest version of Windows server.

Bug fixes

• Previously, the load balancer service would become unstable when the backing deployment had multiple pods scheduled on different Windows nodes. This issue has been fixed. (BZ#1905950)

• Previously, WMCO added the public key annotation windowsmachineconfig.openshift.io/pub-key-hash to Linux nodes. Now, WMCO no longer adds an annotation to Linux nodes. ()

• Previously, when users provided an invalid private key, the WMCO would fail. With this update, the WMCO produces an error alerting the user of an invalid key. (BZ#1929579)

• Previously, the kube-proxy service would crash upon the creation of a load balancer service when the backing development had multiple pods scheduled on different Windows nodes. This issue has now been fixed. ()

RHSA-2021:3001 - Windows Container support for OKD security update

As part of the previously noted bug fix (), an update for Windows kube-proxy is now available for Red Hat Windows Machine Config Operator 2.0.1. Details of the update are documented in the RHSA-2021:2130 advisory.

Known issues