reuse discovered ip data (istio#22772)

Signed-off-by: Rama Chavali <rama.rao@salesforce.com>

pilot/pkg/model/context.go

@@ -155,6 +155,9 @@ type Proxy struct {
 
 	// Indicates wheteher proxy supports IPv4 addresses
 	ipv4Support bool
+
+	// GlobalUnicastIP stores the globacl unicast IP if available, otherwise nil
+	GlobalUnicastIP string
 }
 
 var (
@@ -589,6 +592,9 @@ func (node *Proxy) DiscoverIPVersions() {
 			// skip it to prevent a panic.
 			continue
 		}
+		if addr.IsGlobalUnicast() {
+			node.GlobalUnicastIP = addr.String()
+		}
 		if addr.To4() != nil {
 			node.ipv4Support = true
 		} else {

pilot/pkg/networking/core/v1alpha3/gateway_test.go

@@ -987,6 +987,7 @@ func TestBuildGatewayListeners(t *testing.T) {
 		env := buildEnv(t, []pilot_model.Config{{Spec: tt.gateway}}, []pilot_model.Config{})
 		proxyGateway.SetGatewaysForProxy(env.PushContext)
 		proxyGateway.ServiceInstances = tt.node.ServiceInstances
+		proxyGateway.DiscoverIPVersions()
 		builder := configgen.buildGatewayListeners(&proxyGateway, env.PushContext, &ListenerBuilder{})
 		var listeners []string
 		for _, l := range builder.gatewayListeners {

pilot/pkg/networking/core/v1alpha3/listener.go

@@ -17,7 +17,6 @@ package v1alpha3
 import (
 	"encoding/json"
 	"fmt"
-	"net"
 	"reflect"
 	"sort"
 	"strconv"
@@ -2096,7 +2095,6 @@ func buildListener(opts buildListenerOpts) *xdsapi.Listener {
 			match = chain.match
 		}
 		if len(chain.sniHosts) > 0 {
-			sort.Strings(chain.sniHosts)
 			fullWildcardFound := false
 			for _, h := range chain.sniHosts {
 				if h == "*" {
@@ -2107,6 +2105,7 @@ func buildListener(opts buildListenerOpts) *xdsapi.Listener {
 				}
 			}
 			if !fullWildcardFound {
+				sort.Strings(chain.sniHosts)
 				match.ServerNames = chain.sniHosts
 			}
 		}
@@ -2298,16 +2297,8 @@ func buildCompleteFilterChain(pluginParams *plugin.InputParams, mutable *istione
 // and if there is at least one ipv4 address other than 127.0.0.1, it will use ipv4 address,
 // if all addresses are ipv6  addresses then ipv6 address will be used to get wildcard and local host address.
 func getActualWildcardAndLocalHost(node *model.Proxy) (string, string) {
-	for i := 0; i < len(node.IPAddresses); i++ {
-		addr := net.ParseIP(node.IPAddresses[i])
-		if addr == nil {
-			// Should not happen, invalid IP in proxy's IPAddresses slice should have been caught earlier,
-			// skip it to prevent a panic.
-			continue
-		}
-		if addr.To4() != nil {
-			return WildcardAddress, LocalhostAddress
-		}
+	if node.SupportsIPv4() {
+		return WildcardAddress, LocalhostAddress
 	}
 	return WildcardIPv6Address, LocalhostIPv6Address
 }
@@ -2316,14 +2307,11 @@ func getActualWildcardAndLocalHost(node *model.Proxy) (string, string) {
 // It looks for an unicast address, if none found, then the default wildcard address is used.
 // This will make the inbound listener bind to instance_ip:port instead of 0.0.0.0:port where applicable.
 func getSidecarInboundBindIP(node *model.Proxy) string {
-	defaultInboundIP, _ := getActualWildcardAndLocalHost(node)
-	for _, ipAddr := range node.IPAddresses {
-		ip := net.ParseIP(ipAddr)
-		// Return the IP if its a global unicast address.
-		if ip != nil && ip.IsGlobalUnicast() {
-			return ip.String()
-		}
+	// Return the IP if its a global unicast address.
+	if len(node.GlobalUnicastIP) > 0 {
+		return node.GlobalUnicastIP
 	}
+	defaultInboundIP, _ := getActualWildcardAndLocalHost(node)
 	return defaultInboundIP
 }
 

pilot/pkg/networking/core/v1alpha3/listener_test.go

@@ -618,6 +618,7 @@ func TestGetActualWildcardAndLocalHost(t *testing.T) {
 		},
 	}
 	for _, tt := range tests {
+		tt.proxy.DiscoverIPVersions()
 		wm, lh := getActualWildcardAndLocalHost(tt.proxy)
 		if wm != tt.expected[0] && lh != tt.expected[1] {
 			t.Errorf("Test %s failed, expected: %s / %s got: %s / %s", tt.name, tt.expected[0], tt.expected[1], wm, lh)
@@ -727,6 +728,7 @@ func testOutboundListenerConflict(t *testing.T, services ...*model.Service) {
 	t.Helper()
 	oldestService := getOldestService(services...)
 	p := &fakePlugin{}
+	proxy.DiscoverIPVersions()
 	listeners := buildOutboundListeners(t, p, &proxy, nil, nil, services...)
 	if len(listeners) != 1 {
 		t.Fatalf("expected %d listeners, found %d", 1, len(listeners))