kubespray/docs/cni.md

CNI

This network plugin only unpacks CNI plugins version cni_version into /opt/cni/bin and instructs kubelet to use cni, that is adds following cli params:

KUBELET_NETWORK_PLUGIN="--network-plugin=cni --cni-conf-dir=/etc/cni/net.d --cni-bin-dir=/opt/cni/bin"

It's intended usage is for custom CNI configuration, e.g. manual routing tables + bridge + loopback CNI plugin outside kubespray scope. Furthermore, it's used for non-kubespray supported CNI plugins which you can install afterward.

You are required to fill /etc/cni/net.d with valid CNI configuration after using kubespray.