Chapter 1. Updating clusters overview

Understanding the OpenShift Update Service: For clusters with internet accessibility, Red Hat provides over-the-air updates through an OpenShift Update Service as a hosted service located behind public APIs.

Installing and configuring the OpenShift Update Service: For clusters with internet accessibility, Red Hat provides over-the-air updates through an OpenShift Container Platform update service as a hosted service located behind public APIs. If you are on a restricted network where disconnected clusters cannot access the public APIs, you can install the OpenShift Update Service locally. For more information, see the following procedures:

Understanding upgrade channels and releases: Upgrade channels allow you to choose an upgrade strategy. Upgrade channels are specific to a minor version of OpenShift Container Platform. The openshift-install binary file for a specific version of OpenShift Container Platform always installs that minor version. In addition to the minor version, you can select from the candidate, fast, stable and eus channel tiers to enable an update strategy that suits the needs of your environment. For more information, see the following:

Updating a cluster using the web console: You can update an OpenShift Container Platform cluster by using the web console. The following steps update a cluster within a minor version. You can use the same instructions for updating a cluster between minor versions.

Updating a cluster using the CLI: You can update an OpenShift Container Platform cluster within a minor version by using the OpenShift CLI (oc). The following steps update a cluster within a minor version. You can use the same instructions for updating a cluster between minor versions.

Updating a cluster that includes RHEL compute machines: If your cluster contains Red Hat Enterprise Linux (RHEL) machines, you must perform additional steps to update those machines. You can review the following sections:

Updating a restricted network cluster: A restricted network environment is one in which your cluster nodes cannot access the internet. You can update a restricted network cluster by using the OpenShift CLI (oc). In a restricted network environment, you can configure your OpenShift Container Platform clusters to receive updates using a local OpenShift Update Service instance. If your mirror host cannot access both the internet and the cluster, you can mirror the images to a file system that is disconnected from that environment and then bring that host or removable media across that gap. If the local container registry and the cluster are connected to the host of the mirror registry, you can directly push the release images to the local registry. For more information, see the following items: