tcproute/udproute support multiple backends

internal/cmd/egctl/testdata/translate/out/quickstart.all.yaml

@@ -104,10 +104,7 @@ xdsIR:
         mergeSlashes: true
       port: 10080
       routes:
-      - backendWeights:
-          invalid: 0
-          valid: 0
-        destination:
+      - destination:
           name: httproute/envoy-gateway-system/backend/rule/0
           settings:
           - endpoints:

internal/gatewayapi/filters.go

@@ -797,7 +797,7 @@ func (t *Translator) processRequestMirrorFilter(
 		return
 	}
 
-	ds, _ := t.processDestination(mirrorBackendRef, filterContext.ParentRef, filterContext.Route, resources)
+	ds := t.processDestination(mirrorBackendRef, filterContext.ParentRef, filterContext.Route, resources)
 
 	newMirror := &ir.RouteDestination{
 		Name:     fmt.Sprintf("%s-mirror-%d", irRouteDestinationName(filterContext.Route, filterContext.RuleIdx), filterIdx),

internal/gatewayapi/route.go

@@ -187,27 +187,27 @@ func (t *Translator) processHTTPRouteRules(httpRoute *HTTPRouteContext, parentRe
 
 		for _, backendRef := range rule.BackendRefs {
 			backendRef := backendRef
-			ds, backendWeight := t.processDestination(backendRef, parentRef, httpRoute, resources)
+			ds := t.processDestination(backendRef, parentRef, httpRoute, resources)
 			if !t.EndpointRoutingDisabled && ds != nil && len(ds.Endpoints) > 0 && ds.AddressType != nil {
 				dstAddrTypeMap[*ds.AddressType]++
 			}
+			if ds == nil {
+				continue
+			}
 
 			for _, route := range ruleRoutes {
 				// If the route already has a direct response or redirect configured, then it was from a filter so skip
 				// processing any destinations for this route.
-				if route.DirectResponse == nil && route.Redirect == nil {
-					if ds != nil && len(ds.Endpoints) > 0 {
-						if route.Destination == nil {
-							route.Destination = &ir.RouteDestination{
-								Name: irRouteDestinationName(httpRoute, ruleIdx),
-							}
-						}
-						route.Destination.Settings = append(route.Destination.Settings, ds)
-						route.BackendWeights.Valid += backendWeight
-					} else {
-						route.BackendWeights.Invalid += backendWeight
+				if route.DirectResponse != nil || route.Redirect != nil {
+					continue
+				}
+
+				if route.Destination == nil {
+					route.Destination = &ir.RouteDestination{
+						Name: irRouteDestinationName(httpRoute, ruleIdx),
 					}
 				}
+				route.Destination.Settings = append(route.Destination.Settings, ds)
 			}
 		}
 
@@ -225,7 +225,8 @@ func (t *Translator) processHTTPRouteRules(httpRoute *HTTPRouteContext, parentRe
 
 		// If the route has no valid backends then just use a direct response and don't fuss with weighted responses
 		for _, ruleRoute := range ruleRoutes {
-			if ruleRoute.Destination == nil && ruleRoute.Redirect == nil {
+			noValidBackends := ruleRoute.Destination == nil || ruleRoute.Destination.ToBackendWeights().Valid == 0
+			if noValidBackends && ruleRoute.Redirect == nil {
 				ruleRoute.DirectResponse = &ir.DirectResponse{
 					StatusCode: 500,
 				}
@@ -493,30 +494,31 @@ func (t *Translator) processGRPCRouteRules(grpcRoute *GRPCRouteContext, parentRe
 
 		for _, backendRef := range rule.BackendRefs {
 			backendRef := backendRef
-			ds, backendWeight := t.processDestination(backendRef, parentRef, grpcRoute, resources)
+			ds := t.processDestination(backendRef, parentRef, grpcRoute, resources)
+			if ds == nil {
+				continue
+			}
+
 			for _, route := range ruleRoutes {
 				// If the route already has a direct response or redirect configured, then it was from a filter so skip
 				// processing any destinations for this route.
-				if route.DirectResponse == nil && route.Redirect == nil {
-					if ds != nil && len(ds.Endpoints) > 0 {
-						if route.Destination == nil {
-							route.Destination = &ir.RouteDestination{
-								Name: irRouteDestinationName(grpcRoute, ruleIdx),
-							}
-						}
-						route.Destination.Settings = append(route.Destination.Settings, ds)
-						route.BackendWeights.Valid += backendWeight
+				if route.DirectResponse != nil || route.Redirect != nil {
+					continue
+				}
 
-					} else {
-						route.BackendWeights.Invalid += backendWeight
+				if route.Destination == nil {
+					route.Destination = &ir.RouteDestination{
+						Name: irRouteDestinationName(grpcRoute, ruleIdx),
 					}
 				}
+				route.Destination.Settings = append(route.Destination.Settings, ds)
 			}
 		}
 
 		// If the route has no valid backends then just use a direct response and don't fuss with weighted responses
 		for _, ruleRoute := range ruleRoutes {
-			if ruleRoute.Destination == nil && ruleRoute.Redirect == nil {
+			noValidBackends := ruleRoute.Destination == nil || ruleRoute.Destination.ToBackendWeights().Valid == 0
+			if noValidBackends && ruleRoute.Redirect == nil {
 				ruleRoute.DirectResponse = &ir.DirectResponse{
 					StatusCode: 500,
 				}
@@ -685,10 +687,6 @@ func (t *Translator) processHTTPRouteParentRefListener(route RouteContext, route
 					ExtensionRefs:         routeRoute.ExtensionRefs,
 					IsHTTP2:               routeRoute.IsHTTP2,
 				}
-				// Don't bother copying over the weights unless the route has invalid backends.
-				if routeRoute.BackendWeights.Invalid > 0 {
-					hostRoute.BackendWeights = routeRoute.BackendWeights
-				}
 				if routeRoute.Traffic != nil {
 					hostRoute.Traffic = &ir.TrafficFeatures{
 						Timeout: routeRoute.Traffic.Timeout,
@@ -752,7 +750,7 @@ func (t *Translator) processTLSRouteParentRefs(tlsRoute *TLSRouteContext, resour
 		for _, rule := range tlsRoute.Spec.Rules {
 			for _, backendRef := range rule.BackendRefs {
 				backendRef := backendRef
-				ds, _ := t.processDestination(backendRef, parentRef, tlsRoute, resources)
+				ds := t.processDestination(backendRef, parentRef, tlsRoute, resources)
 				if ds != nil {
 					destSettings = append(destSettings, ds)
 				}
@@ -890,27 +888,16 @@ func (t *Translator) processUDPRouteParentRefs(udpRoute *UDPRouteContext, resour
 			)
 			continue
 		}
-		if len(udpRoute.Spec.Rules[0].BackendRefs) != 1 {
-			routeStatus := GetRouteStatus(udpRoute)
-			status.SetRouteStatusCondition(routeStatus,
-				parentRef.routeParentStatusIdx,
-				udpRoute.GetGeneration(),
-				gwapiv1.RouteConditionResolvedRefs,
-				metav1.ConditionFalse,
-				"InvalidBackend",
-				"One and only one backend is supported",
-			)
-			continue
-		}
 
-		backendRef := udpRoute.Spec.Rules[0].BackendRefs[0]
-		ds, _ := t.processDestination(backendRef, parentRef, udpRoute, resources)
-		// Skip further processing if route destination is not valid
-		if ds == nil || len(ds.Endpoints) == 0 {
-			continue
+		for _, backendRef := range udpRoute.Spec.Rules[0].BackendRefs {
+			ds := t.processDestination(backendRef, parentRef, udpRoute, resources)
+			if ds == nil {
+				continue
+			}
+
+			destSettings = append(destSettings, ds)
 		}
 
-		destSettings = append(destSettings, ds)
 		// If no negative condition has been set for ResolvedRefs, set "ResolvedRefs=True"
 		if !parentRef.HasCondition(udpRoute, gwapiv1.RouteConditionResolvedRefs, metav1.ConditionFalse) {
 			routeStatus := GetRouteStatus(udpRoute)
@@ -1019,7 +1006,6 @@ func (t *Translator) ProcessTCPRoutes(tcpRoutes []*gwapiv1a2.TCPRoute, gateways
 
 func (t *Translator) processTCPRouteParentRefs(tcpRoute *TCPRouteContext, resources *Resources, xdsIR XdsIRMap) {
 	for _, parentRef := range tcpRoute.ParentRefs {
-
 		// Need to compute Route rules within the parentRef loop because
 		// any conditions that come out of it have to go on each RouteParentStatus,
 		// not on the Route as a whole.
@@ -1038,26 +1024,17 @@ func (t *Translator) processTCPRouteParentRefs(tcpRoute *TCPRouteContext, resour
 			)
 			continue
 		}
-		if len(tcpRoute.Spec.Rules[0].BackendRefs) != 1 {
-			routeStatus := GetRouteStatus(tcpRoute)
-			status.SetRouteStatusCondition(routeStatus,
-				parentRef.routeParentStatusIdx,
-				tcpRoute.GetGeneration(),
-				gwapiv1.RouteConditionResolvedRefs,
-				metav1.ConditionFalse,
-				"InvalidBackend",
-				"One and only one backend is supported",
-			)
-			continue
-		}
 
-		backendRef := tcpRoute.Spec.Rules[0].BackendRefs[0]
-		ds, _ := t.processDestination(backendRef, parentRef, tcpRoute, resources)
-		// Skip further processing if route destination is not valid
-		if ds == nil || len(ds.Endpoints) == 0 {
-			continue
+		for _, backendRef := range tcpRoute.Spec.Rules[0].BackendRefs {
+			backendRef := backendRef
+			ds := t.processDestination(backendRef, parentRef, tcpRoute, resources)
+			if ds == nil {
+				continue
+			}
+
+			destSettings = append(destSettings, ds)
 		}
-		destSettings = append(destSettings, ds)
+
 		// If no negative condition has been set for ResolvedRefs, set "ResolvedRefs=True"
 		if !parentRef.HasCondition(tcpRoute, gwapiv1.RouteConditionResolvedRefs, metav1.ConditionFalse) {
 			routeStatus := GetRouteStatus(tcpRoute)
@@ -1088,9 +1065,13 @@ func (t *Translator) processTCPRouteParentRefs(tcpRoute *TCPRouteContext, resour
 			accepted = true
 			irKey := t.getIRKey(listener.gateway)
 
-			tls := ir.TLS{
-				Terminate: irTLSConfigs(listener.tlsSecrets),
+			var tls *ir.TLS
+			if len(listener.tlsSecrets) > 0 {
+				tls = &ir.TLS{
+					Terminate: irTLSConfigs(listener.tlsSecrets),
+				}
 			}
+
 			if listener.Hostname != nil {
 				tls.TLSInspectorConfig = &ir.TLSInspectorConfig{
 					SNIs: []string{string(*listener.Hostname)},
@@ -1105,7 +1086,7 @@ func (t *Translator) processTCPRouteParentRefs(tcpRoute *TCPRouteContext, resour
 						Name:     irRouteDestinationName(tcpRoute, -1 /*rule index*/),
 						Settings: destSettings,
 					},
-					TLS: &tls,
+					TLS: tls,
 				}
 				irListener.Routes = append(irListener.Routes, irRoute)
 
@@ -1145,10 +1126,8 @@ func (t *Translator) processTCPRouteParentRefs(tcpRoute *TCPRouteContext, resour
 // returns the weight for the backend so that 500 error responses can be returned for invalid backends in
 // the same proportion as the backend would have otherwise received
 func (t *Translator) processDestination(backendRefContext BackendRefContext,
-	parentRef *RouteParentContext,
-	route RouteContext,
-	resources *Resources,
-) (ds *ir.DestinationSetting, backendWeight uint32) {
+	parentRef *RouteParentContext, route RouteContext, resources *Resources,
+) (ds *ir.DestinationSetting) {
 	routeType := GetRouteType(route)
 	weight := uint32(1)
 	backendRef := GetBackendRef(backendRefContext)
@@ -1158,12 +1137,13 @@ func (t *Translator) processDestination(backendRefContext BackendRefContext,
 
 	backendNamespace := NamespaceDerefOr(backendRef.Namespace, route.GetNamespace())
 	if !t.validateBackendRef(backendRefContext, parentRef, route, resources, backendNamespace, routeType) {
-		return nil, weight
+		// return with empty endpoint means the backend is invalid
+		return &ir.DestinationSetting{Weight: &weight}
 	}
 
 	// Skip processing backends with 0 weight
 	if weight == 0 {
-		return nil, weight
+		return nil
 	}
 
 	var (
@@ -1256,7 +1236,7 @@ func (t *Translator) processDestination(backendRefContext BackendRefContext,
 		AddressType: addrType,
 		TLS:         backendTLS,
 	}
-	return ds, weight
+	return ds
 }
 
 func inspectAppProtocolByRouteKind(kind gwapiv1.Kind) ir.AppProtocol {

internal/gatewayapi/testdata/backendtlspolicy-ca-only.out.yaml

@@ -142,10 +142,7 @@ xdsIR:
         mergeSlashes: true
       port: 10080
       routes:
-      - backendWeights:
-          invalid: 0
-          valid: 0
-        destination:
+      - destination:
           name: httproute/envoy-gateway/httproute-btls/rule/0
           settings:
           - addressType: IP

internal/gatewayapi/testdata/backendtlspolicy-default-ns.out.yaml

@@ -142,10 +142,7 @@ xdsIR:
         mergeSlashes: true
       port: 10080
       routes:
-      - backendWeights:
-          invalid: 0
-          valid: 0
-        destination:
+      - destination:
           name: httproute/envoy-gateway/httproute-btls/rule/0
           settings:
           - addressType: IP

internal/gatewayapi/testdata/backendtlspolicy-invalid-ca.out.yaml

@@ -142,10 +142,7 @@ xdsIR:
         mergeSlashes: true
       port: 10080
       routes:
-      - backendWeights:
-          invalid: 0
-          valid: 0
-        destination:
+      - destination:
           name: httproute/envoy-gateway/httproute-btls/rule/0
           settings:
           - addressType: IP

internal/gatewayapi/testdata/backendtlspolicy-system-truststore.out.yaml

@@ -139,10 +139,7 @@ xdsIR:
         mergeSlashes: true
       port: 10080
       routes:
-      - backendWeights:
-          invalid: 0
-          valid: 0
-        destination:
+      - destination:
           name: httproute/envoy-gateway/httproute-btls/rule/0
           settings:
           - addressType: IP

internal/gatewayapi/testdata/backendtlspolicy-without-referencegrant.out.yaml

@@ -143,10 +143,7 @@ xdsIR:
         mergeSlashes: true
       port: 10080
       routes:
-      - backendWeights:
-          invalid: 0
-          valid: 0
-        destination:
+      - destination:
           name: httproute/envoy-gateway/httproute-btls/rule/0
           settings:
           - addressType: IP

internal/gatewayapi/testdata/backendtrafficpolicy-override-replace.out.yaml

@@ -218,10 +218,7 @@ xdsIR:
         mergeSlashes: true
       port: 10080
       routes:
-      - backendWeights:
-          invalid: 0
-          valid: 0
-        destination:
+      - destination:
           name: httproute/default/httproute-1/rule/0
           settings:
           - addressType: IP
@@ -241,10 +238,7 @@ xdsIR:
           loadBalancer:
             consistentHash:
               sourceIP: true
-      - backendWeights:
-          invalid: 0
-          valid: 0
-        destination:
+      - destination:
           name: httproute/default/httproute-2/rule/0
           settings:
           - addressType: IP

internal/gatewayapi/testdata/backendtrafficpolicy-status-conditions.out.yaml

@@ -545,9 +545,10 @@ xdsIR:
         mergeSlashes: true
       port: 10080
       routes:
-      - backendWeights:
-          invalid: 1
-          valid: 0
+      - destination:
+          name: httproute/envoy-gateway/httproute-1/rule/0
+          settings:
+          - weight: 1
         directResponse:
           statusCode: 500
         hostname: '*'
@@ -573,9 +574,10 @@ xdsIR:
         mergeSlashes: true
       port: 10080
       routes:
-      - backendWeights:
-          invalid: 1
-          valid: 0
+      - destination:
+          name: grpcroute/envoy-gateway/grpcroute-1/rule/0
+          settings:
+          - weight: 1
         directResponse:
           statusCode: 500
         headerMatches: