Adding Nodes to a Cluster
Learn how to add extra nodes to a Red Hat OpenShift cluster deployed in OCI.
Prerequisites
Before you begin, ensure you have the following:
-
A functioning OpenShift cluster in OCI.
-
Access to the OpenShift Console and the cluster provisioned in OCI, including its
kubeconfigfile. -
An ISO image for booting the nodes added to the target cluster. Note that this image must be generated for the add nodes operation and differs from the image used for the initial cluster creation.
- Assisted Installer clusters: If you used the Assisted Installer to create your cluster, you can use either the Red Hat Hybrid Cloud Console or the OpenShift CLI (oc) version 4.17 or later to create the image. See Adding hosts with the web console and Use the OpenShift CLI (oc) to generate an ISO image (Red Hat documentation) for instructions.
- Agent-based Installer clusters: If you used the agent-based installer to create your cluster, you must use the OpenShift CLI (oc) version 4.17 or later to create the image. See Use the OpenShift CLI (oc) to generate an ISO image for details.
-
Permissions to manage OCI Compute instances and load balancers. See the Overview of IAM and Common Policies for more information.
Part 1: Provision Compute Nodes in OCI
Follow the instructions in this section to provision OCI
Compute nodes using the add-nodes-v1.x.x.zip file in the Resource Manager service.
-
Navigate to the oci-openshift-releases page in GitHub. From the Assets section of the release, download the
add-nodes-v1.x.x.zipfile, where "1.x.x" refers to the release number. For example, release 1.0.0 of the file is namedadd-nodes-v1.0.0.zip - Sign in to the OCI Console. If you need instructions, see Sign In to the Console in the OCI Getting Started guide.
- Open the navigation menu and select Developer Services. Under Resource Manager, select Stacks.
- Select Create stack
-
In the Stack information section, select the My configuration. Select .Zip file and upload the
add-nodes.zipfile. After specifying the configuration source, select Next. - Specify the requested values in the OpenShift Cluster Configuration section. You will need the OCIDs for your OCI tenancy, the compartment that contains your OpenShift cluster. For the OpenShift Image Source URI, paste in the pre-authenticated request value for the ISO image for adding nodes that you uploaded to OCI Object Storage. See Prerequisites in this topic for more information on generating this image.
- For the Control Plane Node Configuration section, specify the details for the control plane nodes you want to add to the cluster. For details on the node variables, including shape, ocpu, memory, boot volume size, and volume performance units (VPUs), see the Creating OpenShift Container Platform Infrastructure topic.
- For the Compute Node Configuration section, specify the details for the compute nodes you want to add to the cluster.
- Select Create to create the stack. The Console redirects to the stack details page for the new stack.
-
On the stack details page, select Apply to create an apply job and provision the new nodes for the cluster. After running an apply job, get the job's details to check its status. Succeeded (
SUCCEEDED) indicates that the job has completed.
Part 2: Add Nodes to Cluster
After you complete the steps in Provision Compute Nodes for an OpenShift Cluster section, your new nodes are ready to be added to your OpenShift cluster. Follow the instructions based on your cluster type.
Assisted Installer Cluster Instructions (Console)
If you created your cluster with the Assisted installer, you can use the Red Hat Hybrid Cloud Console and the cluster console to add your new nodes to the cluster and approve their certificate signing requests (CRSs).
Alternately, you can perform these tasks using the OpenShift CLI (oc) version 4.17 or later. To use the CLI, follow the instructions in Add nodes to a cluster with the CLI.
-
Select Compute, then select Nodes to navigate to the list of nodes available to your cluster.
-
In the Certificate approval required dialog, select Approve to add the node to your cluster. If the node has a pending server certificated signing request, the node status changes to Not Ready.
-
For nodes in the "not ready" state, select the Not Ready link to open the Node status dialog. Review the signing request information, then select Approve to complete the signing process and let the node take workloads within cluster.
Agent-based Installer Cluster Instructions (CLI)
If you created your cluster with the Agent-based installer, you must use the OpenShift CLI (oc) version 4.17 or later to add your new nodes to the cluster and approve their certificate signing requests (CRSs). Note that you will need your kubeconfig file to connect to your target cluster with the CLI. See Adding nodes to your cluster in the Red Hat OpenShift CLI (oc) documentation for more information.
- Create an active connection to your target cluster in the CLI.
-
Confirm that the nodes are booted and ready to be added to the cluster by running the following command:
$ oc adm node-image monitor --ip-addresses <ip_addresses>where
<ip_addresses>specifies a list of the IP addresses of the nodes that are being added. -
Approve the CSRs by running the following command for each CSR:
$ oc adm certificate approve <csr_name>If you need information about pending CSRs, run the following command:
$ oc get csr