From b78465b491e3c226a3b956aa2f8eb42825a65eec Mon Sep 17 00:00:00 2001
From: John Maguire <john.maguire@hashicorp.com>
Date: Tue, 17 Oct 2023 11:08:04 -0400
Subject: [PATCH] [NET-5810] CE changes for multiple virtual hosts (#19246)

CE changes for multiple virtual hosts
---
 agent/xds/listeners_apigateway.go             | 12 ++++---
 ...eway-with-multiple-hostnames.latest.golden | 34 ++++++-------------
 2 files changed, 17 insertions(+), 29 deletions(-)

diff --git a/agent/xds/listeners_apigateway.go b/agent/xds/listeners_apigateway.go
index a4611895e290..771a48297203 100644
--- a/agent/xds/listeners_apigateway.go
+++ b/agent/xds/listeners_apigateway.go
@@ -152,7 +152,11 @@ func (s *ResourceGenerator) makeAPIGatewayListeners(address string, cfgSnap *pro
 
 			routes := make([]*structs.HTTPRouteConfigEntry, 0, len(readyListener.routeReferences))
 			for _, routeRef := range maps.Keys(readyListener.routeReferences) {
-				route, _ := cfgSnap.APIGateway.HTTPRoutes.Get(routeRef)
+				route, ok := cfgSnap.APIGateway.HTTPRoutes.Get(routeRef)
+				if !ok {
+					return nil, fmt.Errorf("missing route for routeRef %s:%s", routeRef.Kind, routeRef.Name)
+				}
+
 				routes = append(routes, route)
 			}
 			consolidatedRoutes := discoverychain.ConsolidateHTTPRoutes(cfgSnap.APIGateway.GatewayConfig, &readyListener.listenerCfg, routes...)
@@ -297,11 +301,9 @@ func getReadyListeners(cfgSnap *proxycfg.ConfigSnapshot) map[string]readyListene
 				continue
 			}
 
-			routeKey := l.Name + routeRef.String()
-
 			for _, upstream := range routeUpstreamsForListener {
 				// Insert or update readyListener for the listener to include this upstream
-				r, ok := ready[routeKey]
+				r, ok := ready[l.Name]
 				if !ok {
 					r = readyListener{
 						listenerKey:      listenerKey,
@@ -312,7 +314,7 @@ func getReadyListeners(cfgSnap *proxycfg.ConfigSnapshot) map[string]readyListene
 				}
 				r.routeReferences[routeRef] = struct{}{}
 				r.upstreams = append(r.upstreams, upstream)
-				ready[routeKey] = r
+				ready[l.Name] = r
 			}
 		}
 	}
diff --git a/agent/xds/testdata/routes/api-gateway-with-multiple-hostnames.latest.golden b/agent/xds/testdata/routes/api-gateway-with-multiple-hostnames.latest.golden
index 9e96457f3c3b..b268a5e5ac5e 100644
--- a/agent/xds/testdata/routes/api-gateway-with-multiple-hostnames.latest.golden
+++ b/agent/xds/testdata/routes/api-gateway-with-multiple-hostnames.latest.golden
@@ -8,52 +8,38 @@
       "virtualHosts": [
         {
           "domains": [
-            "backend.example.com",
-            "backend.example.com:8080"
+            "frontend.example.com",
+            "frontend.example.com:8080"
           ],
-          "name": "api-gateway-http-5a84e719",
+          "name": "api-gateway-http-54620b06",
           "routes": [
             {
               "match": {
                 "prefix": "/"
               },
               "route": {
-                "cluster": "backend.default.dc1.internal.11111111-2222-3333-4444-555555555555.consul"
+                "cluster": "frontend.default.dc1.internal.11111111-2222-3333-4444-555555555555.consul"
               }
             }
           ]
-        }
-      ]
-    },
-    {
-      "@type": "type.googleapis.com/envoy.config.route.v3.RouteConfiguration",
-      "name": "8080",
-      "validateClusters": true,
-      "virtualHosts": [
+        },
         {
           "domains": [
-            "frontend.example.com",
-            "frontend.example.com:8080"
+            "backend.example.com",
+            "backend.example.com:8080"
           ],
-          "name": "api-gateway-http-54620b06",
+          "name": "api-gateway-http-5a84e719",
           "routes": [
             {
               "match": {
                 "prefix": "/"
               },
               "route": {
-                "cluster": "frontend.default.dc1.internal.11111111-2222-3333-4444-555555555555.consul"
+                "cluster": "backend.default.dc1.internal.11111111-2222-3333-4444-555555555555.consul"
               }
             }
           ]
-        }
-      ]
-    },
-    {
-      "@type": "type.googleapis.com/envoy.config.route.v3.RouteConfiguration",
-      "name": "8080",
-      "validateClusters": true,
-      "virtualHosts": [
+        },
         {
           "domains": [
             "*.example.com",