Gateway

The `Gateway` resource is GA and has been part of the Standard Channel since
`v0.5.0`. For more information on release channels, refer to our [versioning
guide](../concepts/versioning).

A Gateway is 1:1 with the lifecycle of the configuration of infrastructure. When a user creates a Gateway, some load balancing infrastructure is provisioned or configured (see below for details) by the GatewayClass controller. Gateway is the resource that triggers actions in this API. Other resources in this API are configuration snippets until a Gateway has been created to link the resources together.

The Gateway spec defines the following:

• GatewayClassName- Defines the name of a GatewayClass object used by this Gateway.
• Listeners- Define the hostnames, ports, protocol, termination, TLS settings and which routes can be attached to a listener.
• Addresses- Define the network addresses requested for this gateway.

If the desired configuration specified in Gateway spec cannot be achieved, the Gateway will be in an error state with details provided by status conditions.

Deployment models

Depending on the GatewayClass, the creation of a Gateway could do any of the following actions:

• Use cloud APIs to create an LB instance.
• Spawn a new instance of a software LB (in this or another cluster).
• Add a configuration stanza to an already instantiated LB to handle the new routes.
• Program the SDN to implement the configuration.
• Something else we haven’t thought of yet…

The API does not specify which one of these actions will be taken.

Gateway Status

GatewayStatus is used to surface the status of a Gateway relative to the desired state represented in spec. GatewayStatus consists of the following:

• Addresses- Lists the IP addresses that have actually been bound to the Gateway.
• Listeners- Provide status for each unique listener defined in spec.
• Conditions- Describe the current status conditions of the Gateway.

Both Conditions and Listeners.conditions follow the conditions pattern used elsewhere in Kubernetes. This is a list that includes a type of condition, the status of the condition and the last time this condition changed.