Kubernetes 101 iptables? #3

I wanted to do some digging about how services work within the nodes , that is how packets are forwarded from the outside , evil and relentless world to the container through bridges etc.

So step 1 , find what port has the service bound to:

port is 30235 , apparently , now let’s look into iptables inside the node.

Notice that is doing a -j (jump) to another chain/extension , in this case KUBE-SVC-URRHIARQWDHNXJTW

lets look into that now:

Cool so lets dig on that chain then “KUBE-SEP-RYFM2HXHC6IPPMAX”:

We see it’s forwarding traffic to 172.17.0.3 , so the only bit left would be to check if we actually have a docker container with address:

Magical!