kube-proxy downgrade job applies 1.8 ADMISSION_CONTROL env on 1.7 master causes apiserver crashes looping #52226
Description
Is this a BUG REPORT or FEATURE REQUEST?:
/kind bug
What happened:
From kube-proxy downgrade test suite: https://k8s-testgrid.appspot.com/sig-network#gci-gce-latest-downgrade-kube-proxy-ds&width=20.
After downgrade, test always fails on "Waiting for new master to respond to API requests".
Checked apiserver's log, found below error (sample log):
failed to initialize admission: Unknown admission plugin: Priority
What you expected to happen:
How to reproduce it (as minimally and precisely as possible):
Downgrade master from 1.8+ to 1.7.X.
@kubernetes/sig-api-machinery-bugs
(Hoping I'm pinging the right group.)