Add Support for User-Defined Gateway Addresses

[danehans]

#352 adds support for managing gateway status addresses. However, this PR does not support user-defined Gateway addresses. Therefore, EG should compare the status address of the Gateway's associated service against the user-defined address and surface the proper Gateway status condition.

[shawnh2]

hi, is this issue still available? i'd like to working on it.

[Xunzhuo]

Great, thanks @shawnh2

[shawnh2]

hi guys, running through few things.

• EG should compare the status address of the Gateway's associated service against the user-defined address and surface the proper Gateway status condition.

  How to define proper?

• I couldn't see any operations on GatewaySpec.Addresses for now in EG, so what's troubling me most is WHAT is our implementation or purpose on this field? FYI, I checked out Contour, it only support a single address, and that address should also be appeared in statusAddresses.

[arkodg]

@shawnh2 the Gateway API allows the user to define a custom address at the Gateway level
https://github.com/kubernetes-sigs/gateway-api/blob/a78e09220feec7947eb1a08b658b45f3b4182d7f/apis/v1beta1/gateway_types.go#L142
we need to first figure out if we / Envoy Gateway can support this feature or not i.e. can we set these addresses on the K8s Service or not.

If that is possible, we will also need to read those values and update the status

gateway/internal/status/gateway.go

Line 25 in f81c011

func UpdateGatewayStatusProgrammedCondition(gw *gwapiv1b1.Gateway, svc *corev1.Service, deployment *appsv1.Deployment) {