The goal of OpenShift 4 is to make upgrades seamless and risk free.
To improve the upgrade success we should be able to detect if the new version is compatible with the existing version before running the actual upgrade.

As OpenShift V4 is composed of many operators, we need to give the operators ability to run some checks before the upgrade to find out if the new incoming version is compatible with the existing version.

Goals:

• A framework for preflight checks and discusses the CVO side implementation of that framework.
• Administrators will be able to run preflight checks without running the upgrade.
• Give Operators (CVO managed) ability to add checks to check if they can safely upgrade to a given release.
• Preflight checks would be idempotent in nature.
• Downloading and verification of images associated with release payload to which the administrator is trying to upgrade should be part of preflight check.