K8S IPTABLES

最近处理一个现场，80端口正常开放，但是从外部curl无法访问，pod内部是没问题的

初步判断时k8s内部的转发出了问题

https://www.tkng.io/services/clusterip/dataplane/iptables/
https://kubernetes.io/blog/2022/09/07/iptables-chains-not-api/
https://dustinspecker.com/posts/iptables-how-kubernetes-services-direct-traffic-to-pods/
https://medium.com/swlh/manage-iptables-firewall-for-docker-kubernetes-daa5870aca4d
https://livebook.manning.com/concept/kubernetes/iptable
https://serenafeng.github.io/2020/03/26/kube-proxy-in-iptables-mode/
https://jimmysong.io/en/blog/understanding-iptables/
https://blog.csdn.net/cloudvtech/article/details/79728920