[release-3.4] clientv3: filter learners members during autosync

clientv3/client.go

@@ -174,7 +174,9 @@ func (c *Client) Sync(ctx context.Context) error {
 	}
 	var eps []string
 	for _, m := range mresp.Members {
-		eps = append(eps, m.ClientURLs...)
+		if len(m.Name) != 0 && !m.IsLearner {
+			eps = append(eps, m.ClientURLs...)
+		}
 	}
 	c.SetEndpoints(eps...)
 	return nil

clientv3/client_test.go

@@ -22,6 +22,7 @@ import (
 	"time"
 
 	"go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"
+	"go.etcd.io/etcd/etcdserver/etcdserverpb"
 	"go.etcd.io/etcd/pkg/testutil"
 
 	"google.golang.org/grpc"
@@ -166,3 +167,51 @@ func TestCloseCtxClient(t *testing.T) {
 		t.Errorf("failed to Close the client. %v", err)
 	}
 }
+
+func TestSyncFiltersMembers(t *testing.T) {
+	defer testutil.AfterTest(t)
+
+	c, _ := New(Config{Endpoints: []string{"http://254.0.0.1:12345"}})
+	c.Cluster = &mockCluster{
+		[]*etcdserverpb.Member{
+			{ID: 0, Name: "", ClientURLs: []string{"http://254.0.0.1:12345"}, IsLearner: false},
+			{ID: 1, Name: "isStarted", ClientURLs: []string{"http://254.0.0.2:12345"}, IsLearner: true},
+			{ID: 2, Name: "isStartedAndNotLearner", ClientURLs: []string{"http://254.0.0.3:12345"}, IsLearner: false},
+		},
+	}
+	c.Sync(context.Background())
+
+	endpoints := c.Endpoints()
+	if len(endpoints) != 1 || endpoints[0] != "http://254.0.0.3:12345" {
+		t.Error("Client.Sync uses learner and/or non-started member client URLs")
+	}
+	c.Close()
+}
+
+type mockCluster struct {
+	members []*etcdserverpb.Member
+}
+
+func (mc *mockCluster) MemberList(ctx context.Context) (*MemberListResponse, error) {
+	return &MemberListResponse{Members: mc.members}, nil
+}
+
+func (mc *mockCluster) MemberAdd(ctx context.Context, peerAddrs []string) (*MemberAddResponse, error) {
+	return nil, nil
+}
+
+func (mc *mockCluster) MemberAddAsLearner(ctx context.Context, peerAddrs []string) (*MemberAddResponse, error) {
+	return nil, nil
+}
+
+func (mc *mockCluster) MemberRemove(ctx context.Context, id uint64) (*MemberRemoveResponse, error) {
+	return nil, nil
+}
+
+func (mc *mockCluster) MemberUpdate(ctx context.Context, id uint64, peerAddrs []string) (*MemberUpdateResponse, error) {
+	return nil, nil
+}
+
+func (mc *mockCluster) MemberPromote(ctx context.Context, id uint64) (*MemberPromoteResponse, error) {
+	return nil, nil
+}