如何将 Cilium Host Routing 由 Legacy 改为 BPF

在 k8s 集群上安装 cilium 之后，发现 Host Routing 为 Legacy，怎么改为 BPF？

$ kubectl exec -it -n kube-system ds/cilium -- cilium status
Host Routing:           Legacy

回答

查看日志发现是因为启用了 enable-endpoint-routes

$ kubectl logs --since 5m ds/cilium -n kube-system | grep legacy                                                                                                    
level=info msg="  --enable-host-legacy-routing='false'" subsys=daemon
level=info msg="BPF host routing is currently not supported with enable-endpoint-routes. Falling back to legacy host routing (enable-host-legacy-routing=true)." subsys=daemon

修改 configmap，改为 enable-endpoint-routes: "false"

kubectl edit cm cilium-config -n kube-system

日志变为

level=info msg="BPF host routing requires kernel 5.10 or newer. Falling back to legacy host routing (enable-host-legacy-routing=true)." subsys=daemon

原来是 linux 内核版本不够，服务器操作系统用的是 Ubuntu 20.04.4，内核版本是 5.4