server

type Callbacks interface {
	// OnStreamOpen is called once an xDS stream is open with a stream ID and the type URL (or "" for ADS).
	// Returning an error will end processing and close the stream. OnStreamClosed will still be called.
	OnStreamOpen(context.Context, int64, string) error
	// OnStreamClosed is called immediately prior to closing an xDS stream with a stream ID.
	OnStreamClosed(int64)
	// OnStreamRequest is called once a request is received on a stream.
	// Returning an error will end processing and close the stream. OnStreamClosed will still be called.
	OnStreamRequest(int64, *v2.DiscoveryRequest) error
	// OnStreamResponse is called immediately prior to sending a response on a stream.
	OnStreamResponse(int64, *v2.DiscoveryRequest, *v2.DiscoveryResponse)
	// OnFetchRequest is called for each Fetch request. Returning an error will end processing of the
	// request and respond with an error.
	OnFetchRequest(context.Context, *v2.DiscoveryRequest) error
	// OnFetchResponse is called immediately prior to sending a response.
	OnFetchResponse(*v2.DiscoveryRequest, *v2.DiscoveryResponse)
}

type HTTPGateway struct {
	// Log is an optional log for errors in response write
	Log log.Logger

	// Server is the underlying gRPC server
	Server Server
}

type Server interface {
	v2grpc.EndpointDiscoveryServiceServer
	v2grpc.ClusterDiscoveryServiceServer
	v2grpc.RouteDiscoveryServiceServer
	v2grpc.ListenerDiscoveryServiceServer
	discoverygrpc.AggregatedDiscoveryServiceServer
	discoverygrpc.SecretDiscoveryServiceServer
	discoverygrpc.RuntimeDiscoveryServiceServer

	// Fetch is the universal fetch method.
	Fetch(context.Context, *v2.DiscoveryRequest) (*v2.DiscoveryResponse, error)
}