Gateway API Glossary

Consumer Route

A Route bound to a workload's Service by a consumer of a given workload, refining the specific consumer's use of the workload.

Gateway Controller

A gateway controller is software that manages the infrastructure associated with routing traffic across contexts using Gateway API, analogous to the earlier ingress controller concept. Gateway controllers often, but not always, run in the cluster where they're managing infrastructure.

East/West traffic

Traffic from workload to workload within a cluster.

Endpoint routing

Endpoint routing is sending requests to a specific Service directly to one of the endpoints of the Service backend, bypassing routing decisions which might be made by the underlying network infrastructure. This is commonly necessary for advanced routing cases like sticky sessions, where the gateway will need to guarantee that every request for a specific session goes to the same endpoint.

North/South traffic

Traffic from outside a cluster to inside a cluster (and vice versa).

Producer Route

A Route bound to a workload's Service by the creator of a given workload, defining what is acceptable use of the workload. Producer routes must always be in the same Namespace as their workload's Service.

Service backend

The part of a Kubernetes Service resource that is a set of endpoints associated with Pods and their IPs. Some east/west traffic happens by having workloads direct requests to specific endpoints within a Service backend.

Service frontend

The part of a Kubernetes Service resource that allocates a DNS record and a cluster IP. East/west traffic often - but not always - works by having workloads direct requests to a Service frontend.

Service mesh

A service mesh is software that manages infrastructure providing security, reliability, and observability for communications between workloads (east/west traffic). Service meshes generally work by intercepting communications between workloads at a very low level, often (though not always) by inserting proxies next to the workload's Pods.

Service routing

Service routing is sending requests to a specific Service to the service frontend, allowing the underlying network infrastructure (usually kube-proxy or a service mesh) to choose the specific endpoint to which the request is routed.

Workload

An instance of computation that provides a function within a cluster, comprising the Pods providing the compute, and the Deployment/Job/ReplicaSet/etc which owns those Pods.