Installing OpenShift on a single node

On the administration host, open a browser and navigate to Red Hat OpenShift Cluster Manager.

Click Create Cluster to create a new cluster.

In the Cluster name field, enter a name for the cluster.

In the Base domain field, enter a base domain. For example:

example.com

<cluster-name>.example.com

Select Install single node OpenShift (SNO) and complete the rest of the wizard steps. Download the discovery ISO.

Make a note of the discovery ISO URL for installing with virtual media.

Attach the RHCOS discovery ISO to the target host.

Configure the boot drive order in the server BIOS settings to boot from the attached discovery ISO and then reboot the server.

On the administration host, return to the browser. Wait for the host to appear in the list of discovered hosts. If necessary, reload the Assisted Clusters page and select the cluster name.

Complete the install wizard steps. Add networking details, including a subnet from the available subnets. Add the SSH public key if necessary.

Monitor the installation’s progress. Watch the cluster events. After the installation process finishes writing the operating system image to the server’s hard disk, the server restarts.

Remove the discovery ISO, and reset the server to boot from the installation drive.

Set the OpenShift Container Platform version:

$ OCP_VERSION=<ocp_version> (1)

Set the host architecture:

$ ARCH=<architecture> (1)

Download the OpenShift Container Platform client (oc) and make it available for use by entering the following commands:

$ curl -k https://mirror.openshift.com/pub/openshift-v4/clients/ocp/$OCP_VERSION/openshift-client-linux.tar.gz -o oc.tar.gz

$ tar zxf oc.tar.gz

$ chmod +x oc

Download the OpenShift Container Platform installer and make it available for use by entering the following commands:

$ curl -k https://mirror.openshift.com/pub/openshift-v4/clients/ocp/$OCP_VERSION/openshift-install-linux.tar.gz -o openshift-install-linux.tar.gz

$ tar zxvf openshift-install-linux.tar.gz

$ chmod +x openshift-install

Retrieve the RHCOS ISO URL by running the following command:

$ ISO_URL=$(./openshift-install coreos print-stream-json | grep location | grep $ARCH | grep iso | cut -d\" -f4)

Download the RHCOS ISO:

$ curl -L $ISO_URL -o rhcos-live.iso

Prepare the install-config.yaml file:

apiVersion: v1
baseDomain: <domain> (1)
compute:
- name: worker
  replicas: 0 (2)
controlPlane:
  name: master
  replicas: 1 (3)
metadata:
  name: <name> (4)
networking: (5)
  clusterNetwork:
  - cidr: 10.128.0.0/14
    hostPrefix: 23
  machineNetwork:
  - cidr: 10.0.0.0/16 (6)
  networkType: OVNKubernetes
  serviceNetwork:
  - 172.30.0.0/16
platform:
  none: {}
bootstrapInPlace:
  installationDisk: /dev/disk/by-id/<disk_id> (7)
pullSecret: '<pull_secret>' (8)
sshKey: |
  <ssh_key> (9)

Generate OpenShift Container Platform assets by running the following commands:

$ mkdir ocp

$ cp install-config.yaml ocp

$ ./openshift-install --dir=ocp create single-node-ignition-config

Embed the ignition data into the RHCOS ISO by running the following commands:

$ alias coreos-installer='podman run --privileged --pull always --rm \
        -v /dev:/dev -v /run/udev:/run/udev -v $PWD:/data \
        -w /data quay.io/coreos/coreos-installer:release'

$ coreos-installer iso ignition embed -fi ocp/bootstrap-in-place-for-live-iso.ign rhcos-live.iso

Attach the modified RHCOS installation ISO to the target host.

Configure the boot drive order in the server BIOS settings to boot from the attached discovery ISO and then reboot the server.

On the administration host, monitor the installation by running the following command:

$ ./openshift-install --dir=ocp wait-for install-complete