Mirroring images for an air-gapped OpenShift cluster

Background

In production, it is common to have an OpenShift cluster that does not have internet access. You can install IBM Cloud Pak for Integration, other IBM Cloud Pak® solutions, and OpenShift Container Platform in an air-gapped (otherwise known as offline or disconnected) cluster environment. Air-gapped installations require that you mirror a typical online installation by using images in your own registry.

The following diagram provides an overview of air-gapped installation scenarios for portable compute, portable storage, and bastion hosts:

All of these scenarios use operator package files to mirror content from a source to a target.

You can store the product code and images in a file system (such as a portable compute device or portable storage device), or in a bastion host, and then transfer them to a local air-gapped network. If you are using a file system, you don't need a bastion host to install in your air-gapped environment.

Sizing for operator packages

Before you begin installation, add the total size for all operator packages that you intend to export. This total is the amount of space that you need to have available on the image registry.