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 with the Docker-formatted container runtime add-on enabled.

Currently, the Docker-formatted container runtime is used in Windows nodes. Kubernetes is deprecating Docker as a container runtime; you can reference the Kubernetes documentation for more information on Docker deprecation. Containerd will be the new supported container runtime for Windows nodes in a future release of Kubernetes.

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 4.7 clusters, the Machine API performs all node host provisioning management actions after the cluster installation finishes. Because of this system, OpenShift Container Platform 4.7 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 worker node on Amazon Web Services (AWS) might define a specific machine type and required metadata.

Machine sets

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

The following custom resources add more capabilities to your cluster:

Machine autoscaler

The MachineAutoscaler resource automatically scales machines in a cloud. You can set the minimum and maximum scaling boundaries for nodes in a specified 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 machine set API. You can set cluster-wide scaling limits for resources such as cores, nodes, memory, GPU, and so on. You can set the priority so that the cluster prioritizes pods so that new nodes are not brought online for less important pods. You can also 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 machine set is scoped to a single zone, so the installation program sends out 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. 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 installed a cluster on vSphere configured with hybrid networking using OVN-Kubernetes.

  • You have defined a custom VXLAN port in your hybrid networking configuration to work around the pod-to-pod connectivity issue between hosts.

Procedure
  1. Create the VM from an updated version of the Windows Server 1909 VM image that includes the Microsoft patch KB4565351. This patch is required to set the VXLAN UDP port, which is required for clusters installed on vSphere. This patch is not available for the Windows Server 2019 VM image.

  2. Create the C:\Users\Administrator\.ssh\authorized_keys file in the Windows VM containing the public key that corresponds to the private key that resides in the secret you created in the openshift-windows-machine-config-operator namespace. The private key of the secret was created when first installing the Windows Machine Config Operator (WMCO) to give OpenShift Container Platform access to Windows VMs. The authorized_keys file is used to configure SSH in the Windows VM.

  3. Configure SSH on the Windows VM by running the following Powershell script:

    # Powershell script to configure SSH on vSphere Windows VMs
    Add-WindowsCapability -Online -Name OpenSSH.Server~~~~0.0.1.0
    $firewallRuleName = "ContainerLogsPort"
    $containerLogsPort = "10250"
    New-NetFirewallRule -DisplayName $firewallRuleName -Direction Inbound -Action Allow -Protocol TCP -LocalPort $containerLogsPort -EdgeTraversalPolicy Allow
    Install-PackageProvider -Name NuGet -MinimumVersion 2.8.5.201 -Force
    Install-Module -Force OpenSSHUtils
    Set-Service -Name ssh-agent -StartupType 'Automatic'
    Set-Service -Name sshd -StartupType 'Automatic'
    Start-Service ssh-agent
    Start-Service sshd
    $pubKeyConf = (Get-Content -path C:\ProgramData\ssh\sshd_config) -replace '#PubkeyAuthentication yes','PubkeyAuthentication yes'
    $pubKeyConf | Set-Content -Path C:\ProgramData\ssh\sshd_config
    $passwordConf = (Get-Content -path C:\ProgramData\ssh\sshd_config) -replace '#PasswordAuthentication yes','PasswordAuthentication yes'
    $passwordConf | Set-Content -Path C:\ProgramData\ssh\sshd_config
    $authFileConf = (Get-Content -path C:\ProgramData\ssh\sshd_config) -replace 'AuthorizedKeysFile __PROGRAMDATA__/ssh/administrators_authorized_keys','#AuthorizedKeysFile __PROGRAMDATA__/ssh/administrators_authorized_keys'
    $authFileConf | Set-Content -Path C:\ProgramData\ssh\sshd_config
    $pubKeyLocationConf = (Get-Content -path C:\ProgramData\ssh\sshd_config) -replace 'Match Group administrators','#Match Group administrators'
    $pubKeyLocationConf | Set-Content -Path C:\ProgramData\ssh\sshd_config
    Restart-Service sshd
    New-item -Path $env:USERPROFILE -Name .ssh -ItemType Directory -force
  4. Install and configure VMware Tools version 11.0.6 or greater on the Windows VM. See the VMware Tools documentation for more information.

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

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

      exclude-nics=

      This entry ensures the following:

      • The cloned vNIC generated on the Windows VM by the hybrid-overlay is not ignored.

      • The VM has an IP address in vCenter.

    2. The VMTools Windows service is running.

  6. Pull all of the required Windows container base images needed for your applications. The images you pull are dependent on the Windows kernel you are using. See Microsoft’s documentation on pulling Windows container base images for more information.

  7. Run the Windows Sysprep tool on the Windows VM:

    C:\> sysprep.exe /generalize /oobe /shutdown /unattend:<path_to_unattend.xml>

    An example unattend.xml is provided, which maintains all the changes needed for the WMCO. For example, the unattend.xml file must ensure the Administrator’s home directory stays intact with the SSH public key. You must customize the example to fit your needs.

    Example unattend.xml
    <?xml version="1.0" encoding="UTF-8"?>
    <!--A sample unattend.xml which helps in setting admin password and running scripts on first boot-->
    <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>windows-host</ComputerName>
             <ProductKey>My_Product_key</ProductKey>
          </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>
                <Password>
                   <Value>MyPassword</Value>
                   <PlainText>true</PlainText>
                </Password>
                <Enabled>true</Enabled>
                <Username>Administrator</Username>
             </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>
                   <PlainText>true</PlainText>
                </AdministratorPassword>
                <LocalAccounts>
                   <LocalAccount wcm:action="add">
                      <Description>Administrator</Description>
                      <DisplayName>Administrator</DisplayName>
                      <Group>Administrators</Group>
                      <Name>Administrator</Name>
                   </LocalAccount>
                </LocalAccounts>
             </UserAccounts>
          </component>
       </settings>
    </unattend>

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
          kind: VSphereMachineProviderSpec
          memoryMiB: 16384
          network:
            devices:
            - networkName: "<vm_network_name>" (5)
          numCPUs: 4
          numCoresPerSocket: 1
          snapshot: ""
          template: <windows_vm_template_name> (6)
          userDataSecret:
            name: windows-user-data (7)
          workspace:
             datacenter: <vcenter_datacenter_name> (8)
             datastore: <vcenter_datastore_name> (9)
             folder: <vcenter_vm_folder_path> (10)
             resourcePool: <vsphere_resource_pool> (11)
             server: <vcenter_server_ip> (12)
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 machine set name. The machine set name cannot be more than 9 characters long, due to the way machine names are generated in vSphere.
3 Configure the machine set as a Windows machine.
4 Configure the Windows node as a compute machine.
5 Specify the vSphere VM network to deploy the machine set to.
6 Specify the full path of the Windows vSphere VM template to use, such as /Datacenter/vm/ocp4-llplx/windows-golden-image. The name must be unique.

Do not specify the original VM template. The VM template must remain off and must be cloned for new RHCOS 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 machine sets can apply configurations to.

7 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 machine sets to consume.
8 Specify the vCenter Datacenter to deploy the machine set on.
9 Specify the vCenter Datastore to deploy the machine set on.
10 Specify the path to the vSphere VM folder in vCenter, such as /dc1/vm/user-inst-5ddjd.
11 Optional: Specify the vSphere resource pool for your Windows VMs.
12 Specify the vCenter server IP or fully qualified domain name.

Creating a machine set

In addition to the ones created by the installation program, you can create your own machine sets 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.

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

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

    1. If you are not sure about which value to set for a specific field, you can check an existing machine set from your cluster.

      $ 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. Check values of a specific machine set:

      $ oc get machineset <machineset_name> -n \
           openshift-machine-api -o yaml
      Example output
      ...
      template:
          metadata:
            labels:
              machine.openshift.io/cluster-api-cluster: agl030519-vplxk (1)
              machine.openshift.io/cluster-api-machine-role: worker (2)
              machine.openshift.io/cluster-api-machine-type: worker
              machine.openshift.io/cluster-api-machineset: agl030519-vplxk-worker-us-east-1a
      1 The cluster ID.
      2 A default node label.
  2. Create the new MachineSet CR:

    $ oc create -f <file_name>.yaml
  3. View the list of machine sets:

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

Additional resources

  • For more information on managing machine sets, see the Machine management section.