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You can create a Windows MachineSet object to serve a specific purpose in your OpenShift Container Platform cluster on VMware vSphere. For example, you might create infrastructure Windows machine sets and related machines so that you can move supporting Windows workloads to the new Windows machines.

Prerequisites

  • You installed the Windows Machine Config Operator (WMCO) using Operator Lifecycle Manager (OLM).

  • You are using a supported Windows Server as the operating system image.

Machine API overview

The Machine API is a combination of primary resources that are based on the upstream Cluster API project and custom OpenShift Container Platform resources.

For OpenShift Container Platform 4.17 clusters, the Machine API performs all node host provisioning management actions after the cluster installation finishes. Because of this system, OpenShift Container Platform 4.17 offers an elastic, dynamic provisioning method on top of public or private cloud infrastructure.

The two primary resources are:

Machines

A fundamental unit that describes the host for a node. A machine has a providerSpec specification, which describes the types of compute nodes that are offered for different cloud platforms. For example, a machine type for a compute node might define a specific machine type and required metadata.

Machine sets

MachineSet resources are groups of compute machines. Compute machine sets are to compute machines as replica sets are to pods. If you need more compute machines or must scale them down, you change the replicas field on the MachineSet resource to meet your compute need.

Control plane machines cannot be managed by compute machine sets.

Control plane machine sets provide management capabilities for supported control plane machines that are similar to what compute machine sets provide for compute machines.

For more information, see “Managing control plane machines".

The following custom resources add more capabilities to your cluster:

Machine autoscaler

The MachineAutoscaler resource automatically scales compute machines in a cloud. You can set the minimum and maximum scaling boundaries for nodes in a specified compute machine set, and the machine autoscaler maintains that range of nodes.

The MachineAutoscaler object takes effect after a ClusterAutoscaler object exists. Both ClusterAutoscaler and MachineAutoscaler resources are made available by the ClusterAutoscalerOperator object.

Cluster autoscaler

This resource is based on the upstream cluster autoscaler project. In the OpenShift Container Platform implementation, it is integrated with the Machine API by extending the compute machine set API. You can use the cluster autoscaler to manage your cluster in the following ways:

  • Set cluster-wide scaling limits for resources such as cores, nodes, memory, and GPU

  • Set the priority so that the cluster prioritizes pods and new nodes are not brought online for less important pods

  • Set the scaling policy so that you can scale up nodes but not scale them down

Machine health check

The MachineHealthCheck resource detects when a machine is unhealthy, deletes it, and, on supported platforms, makes a new machine.

In OpenShift Container Platform version 3.11, you could not roll out a multi-zone architecture easily because the cluster did not manage machine provisioning. Beginning with OpenShift Container Platform version 4.1, this process is easier. Each compute machine set is scoped to a single zone, so the installation program sends out compute machine sets across availability zones on your behalf. And then because your compute is dynamic, and in the face of a zone failure, you always have a zone for when you must rebalance your machines. In global Azure regions that do not have multiple availability zones, you can use availability sets to ensure high availability. The autoscaler provides best-effort balancing over the life of a cluster.

Preparing your vSphere environment for Windows container workloads

You must prepare your vSphere environment for Windows container workloads by creating the vSphere Windows VM golden image and enabling communication with the internal API server for the WMCO.

Creating the vSphere Windows VM golden image

Create a vSphere Windows virtual machine (VM) golden image.

Prerequisites
  • You have created a private/public key pair, which is used to configure key-based authentication in the OpenSSH server. The private key must also be configured in the Windows Machine Config Operator (WMCO) namespace. This is required to allow the WMCO to communicate with the Windows VM. See the "Configuring a secret for the Windows Machine Config Operator" section for more details.

You must use Microsoft PowerShell commands in several cases when creating your Windows VM. PowerShell commands in this guide are distinguished by the PS C:\> prefix.

Procedure
  1. Select a compatible Windows Server version. Currently, the Windows Machine Config Operator (WMCO) stable version supports Windows Server 2022 Long-Term Servicing Channel with the OS-level container networking patch KB5012637.

  2. Create a new VM in the vSphere client using the VM golden image with a compatible Windows Server version. For more information about compatible versions, see the "Windows Machine Config Operator prerequisites" section of the "Red Hat OpenShift support for Windows Containers release notes."

    The virtual hardware version for your VM must meet the infrastructure requirements for OpenShift Container Platform. For more information, see the "VMware vSphere infrastructure requirements" section in the OpenShift Container Platform documentation. Also, you can refer to VMware’s documentation on virtual machine hardware versions.

  3. Install and configure VMware Tools version 11.0.6 or greater on the Windows VM. See the VMware Tools documentation for more information.

  4. After installing VMware Tools on the Windows VM, verify the following:

    1. The C:\ProgramData\VMware\VMware Tools\tools.conf file exists with the following entry:

      exclude-nics=

      If the tools.conf file does not exist, create it with the exclude-nics option uncommented and set as an empty value.

      This entry ensures the cloned vNIC generated on the Windows VM by the hybrid-overlay is not ignored.

    2. The Windows VM has a valid IP address in vCenter:

      C:\> ipconfig
    3. The VMTools Windows service is running:

      PS C:\> Get-Service -Name VMTools | Select Status, StartType
  5. Install and configure the OpenSSH Server on the Windows VM. See Microsoft’s documentation on installing OpenSSH for more details.

  6. Set up SSH access for an administrative user. See Microsoft’s documentation on the Administrative user to do this.

    The public key used in the instructions must correspond to the private key you create later in the WMCO namespace that holds your secret. See the "Configuring a secret for the Windows Machine Config Operator" section for more details.

  7. You must create a new firewall rule in the Windows VM that allows incoming connections for container logs. Run the following PowerShell command to create the firewall rule on TCP port 10250:

    PS C:\> New-NetFirewallRule -DisplayName "ContainerLogsPort" -LocalPort 10250 -Enabled True -Direction Inbound -Protocol TCP -Action Allow -EdgeTraversalPolicy Allow
  8. Clone the Windows VM so it is a reusable image. Follow the VMware documentation on how to clone an existing virtual machine for more details.

  9. In the cloned Windows VM, run the Windows Sysprep tool:

    C:\> C:\Windows\System32\Sysprep\sysprep.exe /generalize /oobe /shutdown /unattend:<path_to_unattend.xml> (1)
    1 Specify the path to your unattend.xml file.

    There is a limit on how many times you can run the sysprep command on a Windows image. Consult Microsoft’s documentation for more information.

    An example unattend.xml is provided, which maintains all the changes needed for the WMCO. You must modify this example; it cannot be used directly.

    Example unattend.xml
    <?xml version="1.0" encoding="UTF-8"?>
    <unattend xmlns="urn:schemas-microsoft-com:unattend">
       <settings pass="specialize">
          <component xmlns:wcm="http://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" name="Microsoft-Windows-International-Core" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS">
             <InputLocale>0409:00000409</InputLocale>
             <SystemLocale>en-US</SystemLocale>
             <UILanguage>en-US</UILanguage>
             <UILanguageFallback>en-US</UILanguageFallback>
             <UserLocale>en-US</UserLocale>
          </component>
          <component xmlns:wcm="http://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" name="Microsoft-Windows-Security-SPP-UX" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS">
             <SkipAutoActivation>true</SkipAutoActivation>
          </component>
          <component xmlns:wcm="http://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" name="Microsoft-Windows-SQMApi" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS">
             <CEIPEnabled>0</CEIPEnabled>
          </component>
          <component xmlns:wcm="http://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" name="Microsoft-Windows-Shell-Setup" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS">
             <ComputerName>winhost</ComputerName> (1)
          </component>
       </settings>
       <settings pass="oobeSystem">
          <component xmlns:wcm="http://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" name="Microsoft-Windows-Shell-Setup" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS">
             <AutoLogon>
                <Enabled>false</Enabled> (2)
             </AutoLogon>
             <OOBE>
                <HideEULAPage>true</HideEULAPage>
                <HideLocalAccountScreen>true</HideLocalAccountScreen>
                <HideOEMRegistrationScreen>true</HideOEMRegistrationScreen>
                <HideOnlineAccountScreens>true</HideOnlineAccountScreens>
                <HideWirelessSetupInOOBE>true</HideWirelessSetupInOOBE>
                <NetworkLocation>Work</NetworkLocation>
                <ProtectYourPC>1</ProtectYourPC>
                <SkipMachineOOBE>true</SkipMachineOOBE>
                <SkipUserOOBE>true</SkipUserOOBE>
             </OOBE>
             <RegisteredOrganization>Organization</RegisteredOrganization>
             <RegisteredOwner>Owner</RegisteredOwner>
             <DisableAutoDaylightTimeSet>false</DisableAutoDaylightTimeSet>
             <TimeZone>Eastern Standard Time</TimeZone>
             <UserAccounts>
                <AdministratorPassword>
                   <Value>MyPassword</Value> (3)
                   <PlainText>true</PlainText>
                </AdministratorPassword>
             </UserAccounts>
          </component>
       </settings>
    </unattend>
    1 Specify the ComputerName, which must follow the Kubernetes' names specification. These specifications also apply to Guest OS customization performed on the resulting template while creating new VMs.
    2 Disable the automatic logon to avoid the security issue of leaving an open terminal with Administrator privileges at boot. This is the default value and must not be changed.
    3 Replace the MyPassword placeholder with the password for the Administrator account. This prevents the built-in Administrator account from having a blank password by default. Follow Microsoft’s best practices for choosing a password.

    After the Sysprep tool has completed, the Windows VM will power off. You must not use or power on this VM anymore.

  10. Convert the Windows VM to a template in vCenter.

Enabling communication with the internal API server for the WMCO on vSphere

The Windows Machine Config Operator (WMCO) downloads the Ignition config files from the internal API server endpoint. You must enable communication with the internal API server so that your Windows virtual machine (VM) can download the Ignition config files, and the kubelet on the configured VM can only communicate with the internal API server.

Prerequisites
  • You have installed a cluster on vSphere.

Procedure
  • Add a new DNS entry for api-int.<cluster_name>.<base_domain> that points to the external API server URL api.<cluster_name>.<base_domain>. This can be a CNAME or an additional A record.

The external API endpoint was already created as part of the initial cluster installation on vSphere.

Sample YAML for a Windows MachineSet object on vSphere

This sample YAML defines a Windows MachineSet object running on VMware vSphere that the Windows Machine Config Operator (WMCO) can react upon.

apiVersion: machine.openshift.io/v1beta1
kind: MachineSet
metadata:
  labels:
    machine.openshift.io/cluster-api-cluster: <infrastructure_id> (1)
  name: <windows_machine_set_name> (2)
  namespace: openshift-machine-api
spec:
  replicas: 1
  selector:
    matchLabels:
      machine.openshift.io/cluster-api-cluster: <infrastructure_id> (1)
      machine.openshift.io/cluster-api-machineset: <windows_machine_set_name> (2)
  template:
    metadata:
      labels:
        machine.openshift.io/cluster-api-cluster: <infrastructure_id> (1)
        machine.openshift.io/cluster-api-machine-role: worker
        machine.openshift.io/cluster-api-machine-type: worker
        machine.openshift.io/cluster-api-machineset: <windows_machine_set_name> (2)
        machine.openshift.io/os-id: Windows (3)
    spec:
      metadata:
        labels:
          node-role.kubernetes.io/worker: "" (4)
      providerSpec:
        value:
          apiVersion: vsphereprovider.openshift.io/v1beta1
          credentialsSecret:
            name: vsphere-cloud-credentials
          diskGiB: 128 (5)
          kind: VSphereMachineProviderSpec
          memoryMiB: 16384
          network:
            devices:
            - networkName: "<vm_network_name>" (6)
          numCPUs: 4
          numCoresPerSocket: 1
          snapshot: ""
          template: <windows_vm_template_name> (7)
          userDataSecret:
            name: windows-user-data (8)
          workspace:
             datacenter: <vcenter_data_center_name> (9)
             datastore: <vcenter_datastore_name> (10)
             folder: <vcenter_vm_folder_path> (11)
             resourcePool: <vsphere_resource_pool> (12)
             server: <vcenter_server_ip> (13)
1 Specify the infrastructure ID that is based on the cluster ID that you set when you provisioned the cluster. You can obtain the infrastructure ID by running the following command:
$ oc get -o jsonpath='{.status.infrastructureName}{"\n"}' infrastructure cluster
2 Specify the Windows compute machine set name. The compute machine set name cannot be more than 9 characters long, due to the way machine names are generated in vSphere.
3 Configure the compute machine set as a Windows machine.
4 Configure the Windows node as a compute machine.
5 Specify the size of the vSphere Virtual Machine Disk (VMDK).

This parameter does not set the size of the Windows partition. You can resize the Windows partition by using the unattend.xml file or by creating the vSphere Windows virtual machine (VM) golden image with the required disk size.

6 Specify the vSphere VM network to deploy the compute machine set to. This VM network must be where other Linux compute machines reside in the cluster.
7 Specify the full path of the Windows vSphere VM template to use, such as golden-images/windows-server-template. The name must be unique.

Do not specify the original VM template. The VM template must remain off and must be cloned for new Windows machines. Starting the VM template configures the VM template as a VM on the platform, which prevents it from being used as a template that compute machine sets can apply configurations to.

8 The windows-user-data is created by the WMCO when the first Windows machine is configured. After that, the windows-user-data is available for all subsequent compute machine sets to consume.
9 Specify the vCenter data center to deploy the compute machine set on.
10 Specify the vCenter datastore to deploy the compute machine set on.
11 Specify the path to the vSphere VM folder in vCenter, such as /dc1/vm/user-inst-5ddjd.
12 Optional: Specify the vSphere resource pool for your Windows VMs.
13 Specify the vCenter server IP or fully qualified domain name.

Creating a compute machine set

In addition to the compute machine sets created by the installation program, you can create your own to dynamically manage the machine compute resources for specific workloads of your choice.

Prerequisites
  • Deploy an OpenShift Container Platform cluster.

  • Install the OpenShift CLI (oc).

  • Log in to oc as a user with cluster-admin permission.

  • In disconnected environments, the image specified in the MachineSet custom resource (CR) must have the OpenSSH server v0.0.1.0 installed.

Procedure
  1. Create a new YAML file that contains the compute machine set custom resource (CR) sample and is named <file_name>.yaml.

    Ensure that you set the <clusterID> and <role> parameter values.

  2. Optional: If you are not sure which value to set for a specific field, you can check an existing compute machine set from your cluster.

    1. To list the compute machine sets in your cluster, run the following command:

      $ oc get machinesets -n openshift-machine-api
      Example output
      NAME                                DESIRED   CURRENT   READY   AVAILABLE   AGE
      agl030519-vplxk-worker-us-east-1a   1         1         1       1           55m
      agl030519-vplxk-worker-us-east-1b   1         1         1       1           55m
      agl030519-vplxk-worker-us-east-1c   1         1         1       1           55m
      agl030519-vplxk-worker-us-east-1d   0         0                             55m
      agl030519-vplxk-worker-us-east-1e   0         0                             55m
      agl030519-vplxk-worker-us-east-1f   0         0                             55m
    2. To view values of a specific compute machine set custom resource (CR), run the following command:

      $ oc get machineset <machineset_name> \
        -n openshift-machine-api -o yaml
      Example output
      apiVersion: machine.openshift.io/v1beta1
      kind: MachineSet
      metadata:
        labels:
          machine.openshift.io/cluster-api-cluster: <infrastructure_id> (1)
        name: <infrastructure_id>-<role> (2)
        namespace: openshift-machine-api
      spec:
        replicas: 1
        selector:
          matchLabels:
            machine.openshift.io/cluster-api-cluster: <infrastructure_id>
            machine.openshift.io/cluster-api-machineset: <infrastructure_id>-<role>
        template:
          metadata:
            labels:
              machine.openshift.io/cluster-api-cluster: <infrastructure_id>
              machine.openshift.io/cluster-api-machine-role: <role>
              machine.openshift.io/cluster-api-machine-type: <role>
              machine.openshift.io/cluster-api-machineset: <infrastructure_id>-<role>
          spec:
            providerSpec: (3)
              ...
      1 The cluster infrastructure ID.
      2 A default node label.

      For clusters that have user-provisioned infrastructure, a compute machine set can only create worker and infra type machines.

      3 The values in the <providerSpec> section of the compute machine set CR are platform-specific. For more information about <providerSpec> parameters in the CR, see the sample compute machine set CR configuration for your provider.
  3. Create a MachineSet CR by running the following command:

    $ oc create -f <file_name>.yaml
Verification
  • View the list of compute machine sets by running the following command:

    $ oc get machineset -n openshift-machine-api
    Example output
    NAME                                       DESIRED   CURRENT   READY   AVAILABLE   AGE
    agl030519-vplxk-windows-worker-us-east-1a  1         1         1       1           11m
    agl030519-vplxk-worker-us-east-1a          1         1         1       1           55m
    agl030519-vplxk-worker-us-east-1b          1         1         1       1           55m
    agl030519-vplxk-worker-us-east-1c          1         1         1       1           55m
    agl030519-vplxk-worker-us-east-1d          0         0                             55m
    agl030519-vplxk-worker-us-east-1e          0         0                             55m
    agl030519-vplxk-worker-us-east-1f          0         0                             55m

    When the new compute machine set is available, the DESIRED and CURRENT values match. If the compute machine set is not available, wait a few minutes and run the command again.

Additional resources