Spotlight on SIG Network

Networking is one of the core pillars of Kubernetes, and the Special Interest Group for Networking (SIG Network) is responsible for developing and maintaining the networking features of Kubernetes. It covers all aspects to ensure Kubernetes provides a reliable and scalable network infrastructure for containerized applications.

In this SIG Network spotlight, Sujay Dey talked with Shane Utt, Software Engineer at Kong, chair of SIG Network and maintainer of Gateway API, on different aspects of the SIG, what are the exciting things going on and how anyone can get involved and contribute here.

Sujay: Hello, and first of all, thanks for the opportunity of learning more about SIG Network. I would love to hear your story, so could you please tell us a bit about yourself, your role, and how you got involved in Kubernetes, especially in SIG Network?

Shane: Hello! Thank you for reaching out.

My Kubernetes journey started while I was working for a small data centre: we were early adopters of Kubernetes and focused on using Kubernetes to provide SaaS products. That experience led to my next position developing a distribution of Kubernetes with a focus on networking. During this period in my career, I was active in SIG Network (predominantly as a consumer).

When I joined Kong my role in the community changed significantly, as Kong actively encourages upstream participation. I greatly increased my engagement and contributions to the Gateway API project during those years, and eventually became a maintainer.

I care deeply about this community and the future of our technology, so when a chair position for the SIG became available, I volunteered my time immediately. I’ve enjoyed working on Kubernetes over the better part of a decade and I want to continue to do my part to ensure our community and technology continues to flourish.

Sujay: I have to say, that was a truely inspiring journey! Now, let us talk a bit more about SIG Network. Since we know it covers a lot of ground, could you please highlight its scope and current focus areas?

Shane: For those who may be uninitiated: SIG Network is responsible for the components, interfaces, and APIs which expose networking capabilities to Kubernetes users and workloads. The charter is a pretty good indication of our scope, but I can add some additional highlights on some of our current areas of focus (this is a non-exhaustive list of sub-projects):

kube-proxy & KPNG

Those familiar with Kubernetes will know the Service API, which enables exposing a group of pods over a network. The current standard implementation of Service is known as kube-proxy, but what may be unfamiliar to people is that there are a growing number of disparate alternative implementations on the rise in recent years. To try and give provisions to these implementations (and also provide some areas of alignment so that implementations do not become too disparate from each other) upstream Kubernetes efforts are underway to create a more modular public interface for kube-proxy. The intention is for implementations to join in around a common set of libraries and speak a common language. This area of focus is known as the KPNG project, and if this sounds interesting to you, please join us in the KPNG community meetings and #sig-network-kpng on Kubernetes Slack.


Today one of the primary requirements for Kubernetes networking is to achieve connectivity between pods in a cluster, satisfying a large number of Kubernetes end-users. However, some use cases require isolated networks and special interfaces for performance-oriented needs (e.g. AF_XDP, memif, SR-IOV). There’s a growing need for special networking configurations in Kubernetes in general. The Multi-Network project exists to improve the management of multiple different networks for pods: anyone interested in some of the lower-level details of pod networking (or anyone having relevant use cases) can join us in the Multi-Network community meetings and #sig-network-multi-network on Kubernetes Slack.

Network Policy

The NetworkPolicy API sub-group was formed to address network security beyond the well-known version 1 of the NetworkPolicy resource. We’ve also been working on the AdminNetworkPolicy resource (previously known as ClusterNetworkPolicy) to provide cluster administrator-focused functionality. The network policy sub-project is a great place to join in if you’re particularly interested in security and CNI, please feel free to join our community meetings and the #sig-network-policy-api channel on Kubernetes Slack.

Gateway API

If you’re specially interested in ingress or mesh networking the Gateway API may be a sub-project you would enjoy. In Gateway API , we’re actively developing the successor to the illustrious Ingress API, which includes a Gateway resource which defines the addresses and listeners of the gateway and various routing types (e.g. HTTPRoute, GRPCRoute, TLSRoute, TCPRoute, UDPRoute, etc.) that attach to Gateways. We also have an initiative within this project called GAMMA, geared towards using Gateway API resources in a mesh network context. There are some up-and-coming side projects within Gateway API as well, including ingress2gateway which is a tool for compiling existing Ingress objects to equivalent Gateway API resources, and Blixt, a Layer4 implementation of Gateway API using Rust/eBPF for the data plane, intended as a testing and reference implementation. If this sounds interesting, we would love to have readers join us in our Gateway API community meetings and #sig-network-gateway-api on Kubernetes Slack.

Sujay: Couldn’t agree more! That was a very informative description, thanks for highlighting them so nicely. As you have already mentioned about the SIG channels to get involved, would you like to add anything about where people like beginners can jump in and contribute?

Shane: For help getting started Kubernetes Slack is a great place to talk to community members and includes several #sig-network-<project> channels as well as our main #sig-network channel. Also, check for issues labelled good-first-issue if you prefer to just dive right into the repositories. Let us know how we can help you!

Sujay: What skills are contributors to SIG Network likely to learn?

Shane: To me, it feels limitless. Practically speaking, it’s very much up to the individual what they want to learn. However, if you just intend to learn as much as you possibly can about networking, SIG Network is a great place to join in and grow your knowledge.

If you’ve ever wondered how Kubernetes Service API works or wanted to implement an ingress controller, this is a great place to join in. If you wanted to dig down deep into the inner workings of CNI, or how the network interfaces at the pod level are configured, you can do that here as well.

We have an awesome and diverse community of people from just about every kind of background you can imagine. This is a great place to share ideas and raise proposals, improving your skills in design, as well as alignment and consensus building.

There’s a wealth of opportunities here in SIG Network. There are lots of places to jump in, and the learning opportunities are boundless.

Sujay: Thanks a lot! It was a really great discussion, we got to know so many great things about SIG Network. I’m sure that many others will find this just as useful as I did.