Evolving Kubernetes Connectivity

Mastering Service Evolution in Kubernetes: A Journey from Userspace to IPVS

Navigating Through the Modes of kube-proxy and Leveraging Dynamic Labels for Seamless Service Updates

Photo by Annie Spratt on Unsplash

Kubernetes services play a crucial role in application connectivity and service discovery within a cluster.

Services Diagram

The kube-proxy running on cluster nodes watches the API server service resources. It presents a type of virtual IP address for services other than ExternalName. The mode for this process has changed over versions of Kubernetes.

In v1.0, services ran in userspace mode as TCP/UDP over IP or Layer 4. In the v1.1 release, the iptables proxy was added and became the default mode starting with v1.2.

In the iptables proxy mode, kube-proxy continues to monitor the API server for changes in Service and Endpoint objects, and updates rules for each object when created or removed.