You can add more compute machines to your Azure Red Hat OpenShift cluster on VMware vSphere.


Creating more Red Hat Enterprise Linux CoreOS (RHCOS) machines in vSphere

You can create more compute machines for your cluster that uses user-provisioned infrastructure on VMware vSphere.

  • Obtain the Base64-encoded Ignition file for your compute machines.

  • You have access to the vSphere template that you created for your cluster.

  1. After the template deploys, deploy a VM for a machine in the cluster.

    1. Right-click the template’s name and click CloneClone to Virtual Machine.

    2. On the Select a name and folder tab, specify a name for the VM. You might include the machine type in the name, such as compute-1.

    3. On the Select a name and folder tab, select the name of the folder that you created for the cluster.

    4. On the Select a compute resource tab, select the name of a host in your datacenter.

    5. Optional: On the Select storage tab, customize the storage options.

    6. On the Select clone options, select Customize this virtual machine’s hardware.

    7. On the Customize hardware tab, click VM OptionsAdvanced.

      • From the Latency Sensitivity list, select High.

      • Click Edit Configuration, and on the Configuration Parameters window, click Add Configuration Params. Define the following parameter names and values:

        • Paste the contents of the Base64-encoded compute Ignition config file for this machine type.

        • Specify base64.

        • disk.EnableUUID: Specify TRUE.

    8. In the Virtual Hardware panel of the Customize hardware tab, modify the specified values as required. Ensure that the amount of RAM, CPU, and disk storage meets the minimum requirements for the machine type. Also, make sure to select the correct network under Add network adapter if there are multiple networks available.

    9. Complete the configuration and power on the VM.

  2. Continue to create more compute machines for your cluster.

Approving the CSRs for your machines

When you add machines to a cluster, two pending certificate signing requests (CSRs) are generated for each machine that you added. You must confirm that these CSRs are approved or, if necessary, approve them yourself.

  • You added machines to your cluster.

  1. Confirm that the cluster recognizes the machines:

    $ oc get nodes
    master-0  Ready     master  63m  v1.16.2
    master-1  Ready     master  63m  v1.16.2
    master-2  Ready     master  64m  v1.16.2
    worker-0  NotReady  worker  76s  v1.16.2
    worker-1  NotReady  worker  70s  v1.16.2

    The output lists all of the machines that you created.

  2. Review the pending CSRs and ensure that you see a client and server request with the Pending or Approved status for each machine that you added to the cluster:

    $ oc get csr
    NAME        AGE     REQUESTOR                                                                   CONDITION
    csr-8b2br   15m     system:serviceaccount:openshift-machine-config-operator:node-bootstrapper   Pending (1)
    csr-8vnps   15m     system:serviceaccount:openshift-machine-config-operator:node-bootstrapper   Pending
    csr-bfd72   5m26s                       Pending (2)
    csr-c57lv   5m26s                       Pending
    1 A client request CSR.
    2 A server request CSR.

    In this example, two machines are joining the cluster. You might see more approved CSRs in the list.

  3. If the CSRs were not approved, after all of the pending CSRs for the machines you added are in Pending status, approve the CSRs for your cluster machines:

    Because the CSRs rotate automatically, approve your CSRs within an hour of adding the machines to the cluster. If you do not approve them within an hour, the certificates will rotate, and more than two certificates will be present for each node. You must approve all of these certificates. After you approve the initial CSRs, the subsequent node client CSRs are automatically approved by the cluster kube-controller-manager. You must implement a method of automatically approving the kubelet serving certificate requests.

    • To approve them individually, run the following command for each valid CSR:

      $ oc adm certificate approve <csr_name> (1)
      1 <csr_name> is the name of a CSR from the list of current CSRs.
    • To approve all pending CSRs, run the following command:

      $ oc get csr -o go-template='{{range .items}}{{if not .status}}{{}}{{"\n"}}{{end}}{{end}}' | xargs oc adm certificate approve
Additional information