Upgrading Red Hat OpenShift

IBM Cloud Pak® for Integration 16.1.1 supports Red Hat OpenShift 4.14, 4.15, 4.16, 4.17, and 4.18. There is no required upgrade of OpenShift beyond version 4.14, but you do have the option to upgrade beyond OpenShift 4.14.

Note: If you are running your cluster on managed OpenShift, such as IBM Cloud, refer to your managed service provider's documentation for OpenShift upgrades, instead of the guidance here.

Important: These operators are not supported on version 4.18: IBM API Connect, IBM DataPower Gateway, and IBM Aspera HSTS. Do not upgrade to 4.18 if using these operators.

Important: Before upgrading Red Hat OpenShift to 4.17 or 4.18, confirm that you have applied the latest fix packs for the 16.1.1 release to all operators and instances. For more information on applying fix packs, see Applying fix packs between major releases.

Before you begin

Review these requirements and prerequisites before proceeding with the upgrade of OpenShift.

This task must be performed by an OpenShift cluster administrator. For more information, see OpenShift roles and permissions.
The OpenShift upgrade process requires users to transition through the intermediate OpenShift versions, for example, when upgrading OpenShift from 4.12 to 4.14, you must upgrade through each OpenShift version (4.12 > 4.13 > 4.14).
- Each intermediate upgrade may take a few hours, so plan accordingly.
- The Red Hat OpenShift Container Platform Update Graph has a tool that provides the appropriate minor versions to use through the intermediate updates. Click the Update Path tile to access. You need Red Hat customer account credentials to get access to the tool.
Cloud Pak for Integration will continue to be supported as the cluster goes through the process of upgrading OpenShift versions. However, the expectation is that you will complete the upgrade within a reasonable period of time, and that the cluster will not run on an intermediate version (such as OpenShift 4.13) indefinitely.
You need to upgrade your storage solutions, including—if you are using it—Red Hat® OpenShift® Data Foundation (ODF), as you upgrade the OCP versions. For example, an upgrade to OpenShift 4.13 should be followed by an upgrade of ODF to 4.13. For each transition, see the following links to the Openshift documentation. To upgrade from:
- ODF 4.12 to 4.13, Red Hat Openshift Data Foundation docs 4.13.
- ODF 4.13 to 4.14, Red Hat Openshift Data Foundation docs 4.14.
  Tip: For OpenShift Data Foundation in a production environment, the optimal minimum deployment is 4 storage nodes, with 3 Object Storage Daemons (OSDs) on each node. This provides much greater data resiliency in the event of any OSD failures.

Upgrading to OpenShift version 4.14

To upgrade OpenShift to version 4.14, follow the procedure in Updating a cluster by using the web console or Updating a cluster by using the CLI.

Troubleshooting

imageContentSource policies are lost during upgrade of OpenShift on IBM Cloud

Symptom: Upgrading OpenShift removes image content source policies.

Cause: ImageContentSourcePolicy (ICSP) holds cluster-wide information about how to handle registry mirror rules. When multiple policies are defined, the outcome of the behavior is defined on each field. For more information, see ImageContentSourcePolicy in the Red Hat OpenShift documentation.

Debugging and solution:
1. Create an ImageContentSourcePolicy on the OpenShift cluster, so that theImageContentSourcePolicy is propagated to the nodes.
2. On each node, log in and search for this file:
```
cat /host/etc/containers/registries.conf
```
  If this file exists on the node but contains only a subset of the rules that are defined in the ImageContentSourcePolicy, reapply the ICSPs.