People generally keep their kubernetes spec files in Git. Be it either the kubernetes .yaml files they apply directly, or helm charts. These files can idempote

People generally keep their kubernetes spec files in Git. Be it either the kubernetes .yaml files they apply directly, or helm charts. These files can idempotently be re-applied to a cluster to restore, or upgrade, the running applications. When you lose your cluster and you restore to a new cluster, you will of course initially deploy the same version of kubernetes as you were using previously. Then once you choose to upgrade to a new version of kubernetes, it can happen that some of the APIs you were using have now been deprecated/removed. This is a very slow process, so you had plenty of time to upgrade ahead of time before being forced to. But let's say you ignore all that, and have chosen to upgrade to a new kubernetes major version and are now forced to upgrade all your yamls. This happens rarely, and recently only because a few BETA APIs have become STABLE and people are now expected to use the STABLE versions. So you go ahead and make those few changes, re-run your deploy and you're done.