Refactor

pilot/pkg/model/endpointshards.go

@@ -101,7 +101,8 @@ func (es *EndpointShards) CopyEndpoints(portMap map[string]int) map[int][]*Istio
 	res := map[int][]*IstioEndpoint{}
 	for _, v := range es.Shards {
 		for _, ep := range v {
-			k := ptr.NonEmptyOrDefault(ep.ServicePortNameKey, ep.ServicePortName)
+			// use the port name as the key, unless LegacyClusterPortKey is set and takes precedence
+			k := ptr.NonEmptyOrDefault(ep.LegacyClusterPortKey, ep.ServicePortName)
 			portNum, f := portMap[k]
 			if !f {
 				continue

pilot/pkg/model/push_context.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"math"
 	"sort"
+	"strconv"
 	"strings"
 	"sync"
 	"time"
@@ -1446,7 +1447,8 @@ func (ps *PushContext) initServiceRegistry(env *Environment, configsUpdate sets.
 	for _, s := range allServices {
 		portMap := map[string]int{}
 		for _, port := range s.Ports {
-			portMap[fmt.Sprintf("%s~%d", port.Name, port.Port)] = port.Port
+			// In EDS we match on port *name*. But for historical reasons, we match on port number for CDS.
+			portMap[strconv.Itoa(port.Port)] = port.Port
 		}
 
 		svcKey := s.Key()

pilot/pkg/model/service.go

@@ -485,8 +485,11 @@ type IstioEndpoint struct {
 	Address string
 
 	// ServicePortName tracks the name of the port, this is used to select the IstioEndpoint by service port.
-	ServicePortName    string
-	ServicePortNameKey string
+	ServicePortName string
+	// LegacyClusterPortKey provides an alternative key from ServicePortName to support legacy quirks in the API.
+	// Basically, EDS merges by port name, but CDS historically ignored port name and matched on number.
+	// Note that for Kubernetes Service, this is identical - its only ServiceEntry where these checks can differ
+	LegacyClusterPortKey string
 
 	// ServiceAccount holds the associated service account.
 	ServiceAccount string

pilot/pkg/serviceregistry/serviceentry/conversion.go

@@ -15,8 +15,8 @@
 package serviceentry
 
 import (
-	"fmt"
 	"net/netip"
+	"strconv"
 	"strings"
 	"time"
 
@@ -286,8 +286,8 @@ func (s *Controller) convertEndpoint(service *model.Service, servicePort *networ
 			EndpointPort:    instancePort,
 			ServicePortName: servicePort.Name,
 
-			ServicePortNameKey: fmt.Sprintf("%s~%d", servicePort.Name, servicePort.Number),
-			Network:         network.ID(wle.Network),
+			LegacyClusterPortKey: strconv.Itoa(int(servicePort.Number)),
+			Network:              network.ID(wle.Network),
 			Locality: model.Locality{
 				Label:     locality,
 				ClusterID: clusterID,
@@ -344,12 +344,12 @@ func (s *Controller) convertServiceEntryToInstances(cfg config.Config, services
 				}
 				out = append(out, &model.ServiceInstance{
 					Endpoint: &model.IstioEndpoint{
-						Address:            string(service.Hostname),
-						EndpointPort:       endpointPort,
-						ServicePortName:    serviceEntryPort.Name,
-						ServicePortNameKey: fmt.Sprintf("%s~%d", serviceEntryPort.Name, serviceEntryPort.Number),
-						Labels:             nil,
-						TLSMode:            model.DisabledTLSModeLabel,
+						Address:              string(service.Hostname),
+						EndpointPort:         endpointPort,
+						ServicePortName:      serviceEntryPort.Name,
+						LegacyClusterPortKey: strconv.Itoa(int(serviceEntryPort.Number)),
+						Labels:               nil,
+						TLSMode:              model.DisabledTLSModeLabel,
 					},
 					Service:     service,
 					ServicePort: convertPort(serviceEntryPort),
@@ -399,7 +399,7 @@ func convertWorkloadInstanceToServiceInstance(workloadInstance *model.WorkloadIn
 			}
 			ep := workloadInstance.Endpoint.ShallowCopy()
 			ep.ServicePortName = serviceEntryPort.Name
-			ep.ServicePortNameKey = fmt.Sprintf("%s~%d", serviceEntryPort.Name, serviceEntryPort.Number)
+			ep.LegacyClusterPortKey = strconv.Itoa(int(serviceEntryPort.Number))
 
 			ep.EndpointPort = targetPort
 			out = append(out, &model.ServiceInstance{