Comment 1 for bug 1866869

Looks like the flannel charm is removing files from /opt/cni/bin/ during its stop hook: https://github.com/charmed-kubernetes/charm-flannel/blob/f79f180a4f8c3f19652f77596537cd9ca359b402/reactive/flannel.py#L312-L314

It shouldn't do that. Those files are installed by kubernetes-worker, not by flannel. And kubernetes-worker doesn't know it's happening, so those files never get re-installed when the new flannel subordinate is deployed.

I think if we remove those three lines, that should fix the issue.