Current situation

Kubernetes tries to write files to /usr/libexec/kubernetes/kubelet-plugins/volume/exec/ which fails on Flatcar.
Workarounds were bind mounts or a sysext with a symlink.

Impact

Does not work by default.

Ideal future situation

/usr/libexec/kubernetes/kubelet-plugins/volume/exec is a symlink to /var/kubernetes/kubelet-plugins/volume/exec in the generic image. A tmpfile rule creates the symlink during image build time and also the target at runtime.