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7.2.6. Creating the Kubernetes manifest and Ignition config files

Because you must modify some cluster definition files and manually start the cluster machines, you must generate the Kubernetes manifest and Ignition config files that the cluster needs to make its machines.

重要

The Ignition config files that the installation program generates contain certificates that expire after 24 hours, which are then renewed at that time. If the cluster is shut down before renewing the certificates and the cluster is later restarted after the 24 hours have elapsed, the cluster automatically recovers the expired certificates. The exception is that you must manually approve the pending node-bootstrapper certificate signing requests (CSRs) to recover kubelet certificates. See the documentation for Recovering from expired control plane certificates for more information.

Prerequisites

  • Obtain the OpenShift Container Platform installation program. For a restricted network installation, these files are on your mirror host.
  • Create the install-config.yaml installation configuration file.

Procedure

  1. Generate the Kubernetes manifests for the cluster:

    $ ./openshift-install create manifests --dir=<installation_directory> 1

    Example output

    INFO Consuming Install Config from target directory
    WARNING Making control-plane schedulable by setting MastersSchedulable to true for Scheduler cluster settings

    1
    For <installation_directory>, specify the installation directory that contains the install-config.yaml file you created.

    Because you create your own compute machines later in the installation process, you can safely ignore this warning.

  2. Remove the Kubernetes manifest files that define the control plane machines:

    $ rm -f <installation_directory>/openshift/99_openshift-cluster-api_master-machines-*.yaml

    By removing these files, you prevent the cluster from automatically generating control plane machines.

  3. Optional: If you do not want the cluster to provision compute machines, remove the Kubernetes manifest files that define the worker machines:

    $ rm -f <installation_directory>/openshift/99_openshift-cluster-api_worker-machineset-*.yaml

    Because you create and manage the worker machines yourself, you do not need to initialize these machines.

  4. Modify the <installation_directory>/manifests/cluster-scheduler-02-config.yml Kubernetes manifest file to prevent pods from being scheduled on the control plane machines:

    1. Open the <installation_directory>/manifests/cluster-scheduler-02-config.yml file.
    2. Locate the mastersSchedulable parameter and set its value to False.
    3. Save and exit the file.
  5. Optional: If you do not want the Ingress Operator to create DNS records on your behalf, remove the privateZone and publicZone sections from the <installation_directory>/manifests/cluster-dns-02-config.yml DNS configuration file:

    apiVersion: config.openshift.io/v1
    kind: DNS
    metadata:
      creationTimestamp: null
      name: cluster
    spec:
      baseDomain: example.openshift.com
      privateZone: 1
        id: mycluster-100419-private-zone
      publicZone: 2
        id: example.openshift.com
    status: {}
    1 2
    Remove this section completely.

    If you do so, you must add ingress DNS records manually in a later step.

  6. Obtain the Ignition config files:

    $ ./openshift-install create ignition-configs --dir=<installation_directory> 1
    1
    For <installation_directory>, specify the same installation directory.

    The following files are generated in the directory:

    .
    ├── auth
    │   ├── kubeadmin-password
    │   └── kubeconfig
    ├── bootstrap.ign
    ├── master.ign
    ├── metadata.json
    └── worker.ign