For the time being I've decided to exploit shared mounts to make
`/opt/cni` and `/etc/cni` work as expected. We need these directories
to appear writable on the host, and allow Weave Net pod to bind-mount
out them in order to install plugin binaries, and allow for vanilla
CNI plugins to be also accessible to kubelet.
Signed-off-by: Ilya Dmitrichenko <errordeveloper@gmail.com>
