Kubernetes Gateway API Graduates to Beta

Authors: Shane Utt (Kong), Rob Scott (Google), Nick Young (VMware), Jeff Apple (HashiCorp)

We are excited to announce the v0.5.0 release of Gateway API. For the first time, several of our most important Gateway API resources are graduating to beta. Additionally, we are starting a new initiative to explore how Gateway API can be used for mesh and introducing new experimental concepts such as URL rewrites. We'll cover all of this and more below.

What is Gateway API?

Gateway API is a collection of resources centered around Gateway resources (which represent the underlying network gateways / proxy servers) to enable robust Kubernetes service networking through expressive, extensible and role-oriented interfaces that are implemented by many vendors and have broad industry support.

Originally conceived as a successor to the well known Ingress API, the benefits of Gateway API include (but are not limited to) explicit support for many commonly used networking protocols (e.g. HTTP, TLS, TCP, UDP) as well as tightly integrated support for Transport Layer Security (TLS). The Gateway resource in particular enables implementations to manage the lifecycle of network gateways as a Kubernetes API.

If you're an end-user interested in some of the benefits of Gateway API we invite you to jump in and find an implementation that suits you. At the time of this release there are over a dozen implementations for popular API gateways and service meshes and guides are available to start exploring quickly.

Getting started

Gateway API is an official Kubernetes API like Ingress. Gateway API represents a superset of Ingress functionality, enabling more advanced concepts. Similar to Ingress, there is no default implementation of Gateway API built into Kubernetes. Instead, there are many different implementations available, providing significant choice in terms of underlying technologies while providing a consistent and portable experience.

Take a look at the API concepts documentation and check out some of the Guides to start familiarizing yourself with the APIs and how they work. When you're ready for a practical application open the implementations page and select an implementation that belongs to an existing technology you may already be familiar with or the one your cluster provider uses as a default (if applicable). Gateway API is a Custom Resource Definition (CRD) based API so you'll need to install the CRDs onto a cluster to use the API.

If you're specifically interested in helping to contribute to Gateway API, we would love to have you! Please feel free to open a new issue on the repository, or join in the discussions. Also check out the community page which includes links to the Slack channel and community meetings.

Release highlights

Graduation to beta

The v0.5.0 release is particularly historic because it marks the growth in maturity to a beta API version (v1beta1) release for some of the key APIs:

• GatewayClass
• Gateway
• HTTPRoute

This achievement was marked by the completion of several graduation criteria:

• API has been widely implemented.
• Conformance tests provide basic coverage for all resources and have multiple implementations passing tests.
• Most of the API surface is actively being used.
• Kubernetes SIG Network API reviewers have approved graduation to beta.

For more information on Gateway API versioning, refer to the official documentation. To see what's in store for future releases check out the next steps section.

Release channels

This release introduces the experimental and standard release channels which enable a better balance of maintaining stability while still enabling experimentation and iterative development.

The standard release channel includes:

• resources that have graduated to beta
• fields that have graduated to standard (no longer considered experimental)

The experimental release channel includes everything in the standard release channel, plus:

• alpha API resources
• fields that are considered experimental and have not graduated to standard channel

Release channels are used internally to enable iterative development with quick turnaround, and externally to indicate feature stability to implementors and end-users.

For this release we've added the following experimental features:

• Routes can attach to Gateways by specifying port numbers
• URL rewrites and path redirects

Other improvements

For an exhaustive list of changes included in the v0.5.0 release, please see the v0.5.0 release notes.

Gateway API for service mesh: the GAMMA Initiative

Some service mesh projects have already implemented support for the Gateway API. Significant overlap between the Service Mesh Interface (SMI) APIs and the Gateway API has inspired discussion in the SMI community about possible integration.

We are pleased to announce that the service mesh community, including representatives from Cilium Service Mesh, Consul, Istio, Kuma, Linkerd, NGINX Service Mesh and Open Service Mesh, is coming together to form the GAMMA Initiative, a dedicated workstream within the Gateway API subproject focused on Gateway API for Mesh Management and Administration.

This group will deliver enhancement proposals consisting of resources, additions, and modifications to the Gateway API specification for mesh and mesh-adjacent use-cases.

This work has begun with an exploration of using Gateway API for service-to-service traffic and will continue with enhancement in areas such as authentication and authorization policy.

Next steps

As we continue to mature the API for production use cases, here are some of the highlights of what we'll be working on for the next Gateway API releases:

• GRPCRoute for gRPC traffic routing
• Route delegation
• Layer 4 API maturity: Graduating TCPRoute, UDPRoute and TLSRoute to beta
• GAMMA Initiative - Gateway API for Service Mesh

If there's something on this list you want to get involved in, or there's something not on this list that you want to advocate for to get on the roadmap please join us in the #sig-network-gateway-api channel on Kubernetes Slack or our weekly community calls.