Set an upgrade window for production clusters
When we release an upgrade (like we're going to do tomorrow), services will go down. Mostly because rolling upgrades are not possible for StatefulSets, and we have 1 replica running for most apps. WordPress has a particularly slow upgrade process because it runs the initContainer again. In any case: services will go down for a few minutes.
I'd like to be able to push these upgrades during daytime, but there's no reason why Flux would have to apply them in the hour it is pushed. The original Stackspin proposal also included setting an upgrade window. Preferably the upgrade window would be configurable by the dashboard in the future, but for now I'd just include it in the stackspin-cluster-variables or something (and include a default so we don't have to wait for a major release to be able to push the change).