sockets - ipvsadm 在 kubeadm 集群中未显示任何条目

Question

我已经安装了 kubeadm 并创建了服务和 pod:

packet@test:~$ kubectl get pod
NAME                                   READY     STATUS    RESTARTS   AGE
udp-server-deployment-6f87f5c9-466ft   1/1       Running   0          5m
udp-server-deployment-6f87f5c9-5j9rt   1/1       Running   0          5m
udp-server-deployment-6f87f5c9-g9wrr   1/1       Running   0          5m
udp-server-deployment-6f87f5c9-ntbkc   1/1       Running   0          5m
udp-server-deployment-6f87f5c9-xlbjq   1/1       Running   0          5m    

packet@test:~$ kubectl get service
NAME                 TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)           AGE
kubernetes           ClusterIP   10.96.0.1       <none>        443/TCP           1h
udp-server-service   NodePort    10.102.67.0     <none>        10001:30001/UDP   6m

但我仍然无法访问 udp-server pod:

packet@test:~$ curl http://192.168.43.161:30001
curl: (7) Failed to connect to 192.168.43.161 port 30001: Connection refused 

在调试时，我可以看到 kube-proxy 正在运行但 IPVS 中没有条目:

root@test:~# ps auxw | grep kube-proxy
root      4050  0.5  0.7  44340 29952 ?        Ssl  14:33   0:25 /usr/local/bin/kube-proxy --config=/var/lib/kube-proxy/config.conf
root      6094  0.0  0.0  14224   968 pts/1    S+   15:48   0:00 grep --color=auto kube-proxy

root@test:~# ipvsadm -ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn

似乎 ipvsadm 中没有条目导致连接超时。

问候，兰吉斯

Answer 1

来自this issue (抛开负载均衡器部分)，

Both externalIPs and status.loadBalancer.ingress[].ip seem to be ignored by kube-proxy in IPVS mode, so external traffic is completely unrouteable.

In contrast, kube-proxy in iptables mode creates DNAT/SNAT rules for external and loadbalancer IPs.

因此请检查添加网络插件( flannel 、 Calico 、...)是否会改善这种情况。

或者查看cloudnativelabs/kube-router ，也是基于ipvs的。

A lean yet powerful alternative to several network components used in typical Kubernetes clusters.
All this from a single DaemonSet/Binary. It doesn't get any easier.