updating_a_cluster.md

This gist provides some additional information referenced in the Ask an OpenShift Admin livestream on January 12th, 2022.

Updating OpenShift Clusters

Triggering an update to the cluster is done the same way, whether you're doing an update between z-streams (e.g. 4.9.8 -> 4.9.13) or an upgrade between y-releases (e.g. 4.8.z -> 4.9.z). There are three primary options:

1. Use the webconsole This is pretty straightforward, browse to the Administration panel, then click the update button. If you're upgrading between y-releases, you may need to change the release stream.

2. Use the CLI If you need to update the channel, you'll need to oc patch the clusterversion object:

   oc patch clusterversion version --type merge -p '{"spec": {"channel": "stable-4.8"}}'

   Once that's done, trigger the update via the oc adm upgrade command:

   # update to the latest version available in the channel
   oc adm upgrade --to-latest=true
   
   # update to a specific version
   oc adm upgrade --to=$version
   
   # update to a specific release image
   oc adm release info quay.io/openshift-release-dev/ocp-release:4.9.12-x86_64
   oc adm upgrade --allow-explicit-upgrade --to-image $IMAGE

3. Use a YAML file This is particularly helpful if you're using GitOps to manage your cluster.

   apiVersion: config.openshift.io/v1
   kind: ClusterVersion
   metadata:
     name: version
   spec:
     channel: stable-4.9
     clusterID: <id>
     desiredUpdate:
         version: 4.9.12

   You can change both the channel and the specific release using this method.