In my project, Istio and Applications are managed by different teams. During Istio upgrade, Istio team typically rolling restart all Pods so they are injected with new version of sidecar. However, in some scenario, application team doesn’t want their Pods to be restarted, hence it blocks Istio team from doing necessary maintenance.
My question is if Istio team upgraded the control plane to latest version, eg 1.8.0, can we leave Pods running 1.7.5 sidecar and let Application team to decide when to restart them? I know it likely works, but is there official confirmation from Istio that this use case is supported for production use?
Kubernetes has very detailed version skew support policy document. But I can’t find anything for Istio.