File /proc/sys/net/bridge/bridge-nf-call-iptables not existing

[HarimbolaSantatra]

Description

When deploying flannel, it produces an error:

Failed to check br_netfilter: stat /proc/sys/net/bridge/bridge-nf-call-iptables: no such file or directory

Steps to reproduce

• kubectl apply -f https://github.com/flannel-io/flannel/releases/latest/download/kube-flannel.yml
• The logs of the container - kubectl logs kube-flannel-ds-zg58f -n kube-flannel (The name of the container may vary) will yield:

Failed to check br_netfilter: stat /proc/sys/net/bridge/bridge-nf-call-iptables: no such file or directory

[HarimbolaSantatra]

So according to this discussion, the br_netfilter module is required. Enable it with:

modprobe br_netfilter

Related issue:

• Required br_netfilter module, not mentioned. #2068
• Kubeadm removed preflight checks