one cluster should have only one transport to reduce the number of TC…

…P connections

Signed-off-by: mengying <[email protected]>

go.mod

@@ -27,6 +27,7 @@ require (
 	github.com/yuin/gopher-lua v0.0.0-20220504180219-658193537a64
 	go.uber.org/mock v0.4.0
 	golang.org/x/net v0.24.0
+	golang.org/x/sync v0.7.0
 	golang.org/x/term v0.19.0
 	golang.org/x/text v0.14.0
 	golang.org/x/time v0.5.0
@@ -174,7 +175,6 @@ require (
 	golang.org/x/exp v0.0.0-20231226003508-02704c960a9b // indirect
 	golang.org/x/mod v0.17.0 // indirect
 	golang.org/x/oauth2 v0.18.0 // indirect
-	golang.org/x/sync v0.7.0 // indirect
 	golang.org/x/sys v0.19.0 // indirect
 	google.golang.org/appengine v1.6.8 // indirect
 	google.golang.org/genproto v0.0.0-20231212172506-995d672761c0 // indirect

pkg/util/proxy/proxy.go

@@ -26,8 +26,10 @@ import (
 	"net/url"
 	"path"
 	"strings"
+	"sync"
 	"time"
 
+	"golang.org/x/sync/singleflight"
 	authenticationv1 "k8s.io/api/authentication/v1"
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/util/httpstream"
@@ -44,6 +46,13 @@ import (
 // SecretGetterFunc is a function to get secret.
 type SecretGetterFunc func(context.Context, string, string) (*corev1.Secret, error)
 
+type clusterEndpointInfo struct {
+	Transport *http.Transport
+}
+
+var clusterEndpointInfoStore sync.Map
+var singleExecution singleflight.Group
+
 // ConnectCluster returns a handler for proxy cluster.
 func ConnectCluster(ctx context.Context, cluster *clusterapis.Cluster, proxyPath string, secretGetter SecretGetterFunc, responder registryrest.Responder) (http.Handler, error) {
 	tlsConfig, err := GetTLSConfigForCluster(ctx, cluster, secretGetter)
@@ -159,12 +168,32 @@ func Location(cluster *clusterapis.Cluster, tlsConfig *tls.Config) (*url.URL, ht
 		return nil, nil, err
 	}
 
-	proxyTransport, err := createProxyTransport(cluster, tlsConfig)
+	if v, ok := clusterEndpointInfoStore.Load(cluster.UID); ok {
+		clusterEndpointsInfo := v.(clusterEndpointInfo)
+		return location, clusterEndpointsInfo.Transport, nil
+	}
+
+	endpointInfo, err, _ := singleExecution.Do(string(cluster.UID), func() (interface{}, error) {
+		if value, ok := clusterEndpointInfoStore.Load(cluster.UID); ok {
+			return value, nil
+		}
+		proxyTransport, err := createProxyTransport(cluster, tlsConfig)
+		if err != nil {
+			return nil, err
+		}
+		clusterEndpointInfoo := clusterEndpointInfo{
+			Transport: proxyTransport,
+		}
+		clusterEndpointInfoStore.Store(cluster.UID, clusterEndpointInfo{
+			Transport: proxyTransport,
+		})
+		return clusterEndpointInfoo, nil
+	})
 	if err != nil {
 		return nil, nil, err
 	}
-
-	return location, proxyTransport, nil
+	transport := endpointInfo.(clusterEndpointInfo).Transport
+	return location, transport, nil
 }
 
 func constructLocation(cluster *clusterapis.Cluster) (*url.URL, error) {