Why my Kubernetes pod network traffic does not go through the iptables NAT table?

Question

我需要在 K8s pod 中根据某些条件将 iptables 规则写入 SNAT 数据包，但网络流量永远不会通过 NAT 表

Answer 1

Why my Kubernetes pod network traffic does not go through the iptables NAT table?

Ans :

Because Kubernetes Dictates so to all CNI. Following is from Kubernetes Documentation

Kubernetes imposes the following fundamental requirements on any networking 
implementation (barring any intentional network segmentation policies):

- pods on a node can communicate with all pods on all nodes without NAT
- agents on a node (e.g. system daemons, kubelet) can communicate with all pods on 
  that node. 
  Note: For those platforms that support Pods running in the host network 
  (e.g. Linux):
  - pods in the host network of a node can communicate with all pods on all nodes 
    without NAT