Remove unused are hosts set check (#16691)

* Remove unused are hosts set check

* Remove all traces of unused 'AreHostsSet' parameter

* Remove unused Hosts attribute

* Remove commented out use of snap.APIGateway.Hosts

agent/proxycfg/api_gateway.go

@@ -392,8 +392,6 @@ func (h *handlerAPIGateway) handleRouteConfigUpdate(ctx context.Context, u Updat
 		snap.APIGateway.Upstreams.set(ref, listener, set)
 	}
 	snap.APIGateway.UpstreamsSet.set(ref, seenUpstreamIDs)
-	// snap.APIGateway.Hosts = TODO
-	snap.APIGateway.AreHostsSet = true
 
 	// Stop watching any upstreams and discovery chains that have become irrelevant
 	for upstreamID, cancelDiscoChain := range snap.APIGateway.WatchedDiscoveryChains {

agent/proxycfg/proxycfg.deepcopy.go

@@ -255,10 +255,6 @@ func (o *configSnapshotAPIGateway) DeepCopy() *configSnapshotAPIGateway {
 	if o.BoundGatewayConfig != nil {
 		cp.BoundGatewayConfig = o.BoundGatewayConfig.DeepCopy()
 	}
-	if o.Hosts != nil {
-		cp.Hosts = make([]string, len(o.Hosts))
-		copy(cp.Hosts, o.Hosts)
-	}
 	if o.Upstreams != nil {
 		cp.Upstreams = make(map[structs.ResourceReference]listenerUpstreamMap, len(o.Upstreams))
 		for k2, v2 := range o.Upstreams {

agent/proxycfg/snapshot.go

@@ -666,8 +666,10 @@ func (r routeUpstreamSet) delete(route structs.ResourceReference) {
 	delete(r, route)
 }
 
-type listenerUpstreamMap map[APIGatewayListenerKey]structs.Upstreams
-type listenerRouteUpstreams map[structs.ResourceReference]listenerUpstreamMap
+type (
+	listenerUpstreamMap    map[APIGatewayListenerKey]structs.Upstreams
+	listenerRouteUpstreams map[structs.ResourceReference]listenerUpstreamMap
+)
 
 func (l listenerRouteUpstreams) set(route structs.ResourceReference, listener APIGatewayListenerKey, upstreams structs.Upstreams) {
 	if _, ok := l[route]; !ok {
@@ -705,13 +707,9 @@ type configSnapshotAPIGateway struct {
 	BoundGatewayConfigLoaded bool
 	BoundGatewayConfig       *structs.BoundAPIGatewayConfigEntry
 
-	// Hosts is the list of extra host entries to add to our leaf cert's DNS SANs
-	Hosts       []string
-	AreHostsSet bool
-
 	// LeafCertWatchCancel is a CancelFunc to use when refreshing this gateway's
 	// leaf cert watch with different parameters.
-	//LeafCertWatchCancel context.CancelFunc
+	// LeafCertWatchCancel context.CancelFunc
 
 	// Upstreams is a list of upstreams this ingress gateway should serve traffic
 	// to. This is constructed from the ingress-gateway config entry, and uses
@@ -1079,7 +1077,6 @@ func (s *ConfigSnapshot) Valid() bool {
 			s.APIGateway.Leaf != nil &&
 			s.APIGateway.GatewayConfigLoaded &&
 			s.APIGateway.BoundGatewayConfigLoaded &&
-			s.APIGateway.AreHostsSet &&
 			s.APIGateway.MeshConfigSet
 	default:
 		return false
@@ -1121,8 +1118,8 @@ func (s *ConfigSnapshot) Clone() *ConfigSnapshot {
 		snap.APIGateway.WatchedDiscoveryChains = nil
 
 		// only api-gateway
-		//snap.APIGateway.LeafCertWatchCancel = nil
-		//snap.APIGateway.
+		// snap.APIGateway.LeafCertWatchCancel = nil
+		// snap.APIGateway.
 	}
 
 	return snap