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When your fancy observability tools have failed you there’s still trusty tpcdump

The was done on Ubuntu. YMMV on other distros.

Exec into a pod

kubectl exec -it my-pod-name sh

Run

cat /sys/class/net/eth0/iflink
> 588 # container eth id

It should return a number, the container eth id

Now run

kubectl describe po my-pod-name | grep Node

To find out the node it’s running on

SSH into the node then run below to find the eni id

ip link | grep 588
> eni89aabc12345

Now use tcpdump to sniff the requests coming in

tcpdump -A -i eni89aabc12345

To capture a specific header

tcpdump -A -i eni89aabc12345 | grep -i X-Real-IP -C 5