/pod-gke-NAT

Problem

  • pod GKE can not connect to VPN network

Reason

  • Pod GKE is not using NAT when going out of GKE worker

Solution

  • Using a daemonSet with "Priviledge: true" toi check & apply NAT on Iptables for every 60s
iptables -A POSTROUTING -d 10.60.0.0/16 -m comment --    comment "NAT-VPN: SNAT for outbound traffic through VPN" -m addrtype ! --  dst-type LOCAL -j MASQUERADE -t nat

Verification

  • ssh to GKE workers
- "iptables-save | grep NAT" => you'll see NAT rules added
  • In the pod, now you can reach VPN network (10.60.0.0/16)

Reference: https://blog.mrtrustor.net/post/iptables-kubernetes/