Rancher Release v2.3.0-alpha3 - Preview Of Windows Containers



We are announcing the preview of Windows Server 2019 containers with Kubernetes 1.14 in Rancher.

As many users may know, Rancher 2.1.0 supported Windows containers in experimental mode. Now that Microsoft has announced the general availability of containers in Windows Server 2019 with Kubernetes 1.14, we have upgraded Rancher to both support the latest version of Windows containers (and Kubernetes) and after the preview is over, make it generally available.

As always, we truly value our users’ feedback and input on the Previews and strive to incorporate as much of it as possible prior to a GA release. Thank you all for your support!

Major Features and Enhancements

  • Support for Windows Server Containers 1809/2019 [#19173] - Ability to add Windows worker nodes to the clusters - With Rancher 2.3.0 Preview 1, users can create Kubernetes 1.14 clusters (type = custom) and add Windows or Linux worker nodes to their clusters. The option to use Flannel in VXLAN and host-gw mode is also available. While most capabilities will work as they work in Linux only clusters, there are some significant limitations and challenges that users should be aware of. We have listed them under Major Known Issues section below.
    Users should note that with this preview release, the older experimental support for Windows in Rancher 2.1.0 will no longer be maintained or upgraded.


  1. Windows Server 2019, Docker EE-basic 18.09, Kubernetes 1.14 and Rancher 2.3.0 Preview 1
  2. Only “custom” clusters are supported
  3. Etcd and Control plane nodes can be Linux only. You also need at least 1 Linux worker node for the cluster to function properly
  4. Flannel is the only supported network plugin in for Windows clusters

Major known issues

  1. For Windows nodes the host image must match the container base image (this is a Microsoft limitation). This means that every major upgrade of the host OS image will require you to recreate your container images or the container may not function properly
  2. Rancher’s inbuilt Prometheus based monitoring won’t work for Windows
  3. Dynamic PVC and static PV with Azure cloud provider need additional steps [#20124] - Please refer to our documentation for more details.
  4. Support for vSphere and AWS cloud provider has not been fully tested and may not work


NOTE - Image Name Changes: Please note that as of v2.0.0, our images will be rancher/rancher and rancher/rancher-agent. If you are using v1.6, please continue to use rancher/server and rancher/agent.


  • rancher/rancher:v2.3.0-alpha3
  • rancher/rancher-agent:v2.3.0-alpha3

NOTE - We’ve introduced a new helm repository to facilitate the deployment of alpha releases. For more details, see our installation documentation.



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