$ OKD_VERSION=<okd_version> (1)
You can install single-node OKD using the Assisted Service or you can generate an installation ISO using openshift-installer
.
To install single-node OKD with the Assisted Service, please refer to the following documentation: * Install OKD using Assisted Service
To install OKD on a single node, first generate the installation ISO, and then boot the server from the ISO. You can monitor the installation using the openshift-install
installation program.
Installing OKD on a single node requires an installation ISO, which you can generate with the following procedure.
Install podman
.
See "Requirements for installing OpenShift on a single node" for networking requirements, including DNS records. |
Set the OKD version:
$ OKD_VERSION=<okd_version> (1)
1 | Replace <okd_version> with the current version, for example, 4.14.0-0.okd-2024-01-26-175629 |
Set the host architecture:
$ ARCH=<architecture> (1)
1 | Replace <architecture> with the target host architecture, for example, aarch64 or x86_64 . |
Download the OKD client (oc
) and make it available for use by entering the following commands:
$ curl -L https://github.com/okd-project/okd/releases/download/$OKD_VERSION/openshift-client-linux-$OKD_VERSION.tar.gz -o oc.tar.gz
$ tar zxf oc.tar.gz
$ chmod +x oc
Download the OKD installer and make it available for use by entering the following commands:
$ curl -L https://github.com/okd-project/okd/releases/download/$OKD_VERSION/openshift-install-linux-$OKD_VERSION.tar.gz -o openshift-install-linux.tar.gz
$ tar zxvf openshift-install-linux.tar.gz
$ chmod +x openshift-install
Retrieve the FCOS 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 FCOS ISO:
$ curl -L $ISO_URL -o fcos-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)
1 | Add the cluster domain name. |
2 | Set the compute replicas to 0 . This makes the control plane node schedulable. |
3 | Set the controlPlane replicas to 1 . In conjunction with the previous compute setting, this setting ensures the cluster runs on a single node. |
4 | Set the metadata name to the cluster name. |
5 | Set the networking details. OVN-Kubernetes is the only allowed network plugin type for single-node clusters. |
6 | Set the cidr value to match the subnet of the single-node OKD cluster. |
7 | Set the path to the installation disk drive, for example, /dev/disk/by-id/wwn-0x64cd98f04fde100024684cf3034da5c2 . |
8 | Copy the pull secret from Red Hat OpenShift Cluster Manager and add the contents to this configuration setting. |
9 | Add the public SSH key from the administration host so that you can log in to the cluster after installation. |
Generate OKD assets by running the following commands:
$ mkdir sno
$ cp install-config.yaml sno
$ ./openshift-install --dir=sno create single-node-ignition-config
Embed the ignition data into the FCOS 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 sno/bootstrap-in-place-for-live-iso.ign fcos-live.iso
See Requirements for installing OpenShift on a single node for more information about installing OKD on a single node.
See Cluster capabilities for more information about enabling cluster capabilities that were disabled before installation.
See Optional cluster capabilities in OKD 4.16 for more information about the features provided by each capability.
Use openshift-install
to monitor the progress of the single-node cluster installation.
Attach the modified FCOS 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=sno wait-for install-complete
The server restarts several times while deploying the control plane.
After the installation is complete, check the environment by running the following command:
$ export KUBECONFIG=sno/auth/kubeconfig
$ oc get nodes
NAME STATUS ROLES AGE VERSION
control-plane.example.com Ready master,worker 10m v1.27.9+e36e183
The documentation for installer-provisioned installation on cloud providers is based on a high availability cluster consisting of three control plane nodes. When referring to the documentation, consider the differences between the requirements for a single-node OKD cluster and a high availability cluster.
A high availability cluster requires a temporary bootstrap machine, three control plane machines, and at least two compute machines. For a single-node OKD cluster, you need only a temporary bootstrap machine and one cloud instance for the control plane node and no worker nodes.
The minimum resource requirements for high availability cluster installation include a control plane node with 4 vCPUs and 100GB of storage. For a single-node OKD cluster, you must have a minimum of 8 vCPU cores and 120GB of storage.
The controlPlane.replicas
setting in the install-config.yaml
file should be set to 1
.
The compute.replicas
setting in the install-config.yaml
file should be set to 0
.
This makes the control plane node schedulable.
The following table contains a list of supported cloud providers and CPU architectures.
Cloud provider | CPU architecture |
---|---|
Amazon Web Service (AWS) |
x86_64 and AArch64 |
Microsoft Azure |
x86_64 |
Google Cloud Platform (GCP) |
x86_64 and AArch64 |
Installing a single-node cluster on AWS requires installer-provisioned installation using the "Installing a cluster on AWS with customizations" procedure.
Installing a single node cluster on Azure requires installer-provisioned installation using the "Installing a cluster on Azure with customizations" procedure.
You can install software using a bootable USB drive that contains an ISO image. Booting the server with the USB drive prepares the server for the software installation.
On the administration host, insert a USB drive into a USB port.
Create a bootable USB drive, for example:
# dd if=<path_to_iso> of=<path_to_usb> status=progress
where:
is the relative path to the downloaded ISO file, for example, fcos-live.iso
.
is the location of the connected USB drive, for example, /dev/sdb
.
After the ISO is copied to the USB drive, you can use the USB drive to install software on the server.