Kubernetes Cookbook - Second Edition

How it works...

On the network protocol stack, the Kubernetes Service relies on the transport layer, working together with the overlay network and kube-proxy. The overlay network of Kubernetes builds up a cluster network by allocating a subnet lease out of a pre-configured address space and storing the network configuration in etcd; on the other hand, kube-proxy helps to forward traffic from the endpoints of Services to the Pods through iptables settings.

Proxy-mode and Service kube-proxy  currently has three modes with different implementation methods: userspace, iptables, and ipvs. The modes affect how the requests of clients reach to certain Pods through the Kubernete Service:

• userspace: kube-proxy opens a random port, called a proxy ...