.*: add list-member command

dm/ctl/ctl.go

@@ -76,6 +76,7 @@ func NewRootCmd() *cobra.Command {
 		master.NewMigrateRelayCmd(),
 		master.NewOperateSourceCmd(),
 		master.NewOfflineWorkerCmd(),
+		master.NewGetLeaderCmd(),
 	)
 	return cmd
 }

dm/ctl/master/get_leader.go

@@ -0,0 +1,56 @@
+// Copyright 2019 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package master
+
+import (
+	"context"
+	"os"
+
+	"github.com/pingcap/dm/dm/ctl/common"
+	"github.com/pingcap/dm/dm/pb"
+
+	"github.com/pingcap/errors"
+	"github.com/spf13/cobra"
+)
+
+// NewGetLeaderCmd creates an GetLeader command
+func NewGetLeaderCmd() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "get-leader",
+		Short: "get master leader",
+		Run:   getLeaderFunc,
+	}
+	return cmd
+}
+
+// getLeaderFunc does get leader request
+func getLeaderFunc(cmd *cobra.Command, _ []string) {
+	if len(cmd.Flags().Args()) > 0 {
+		cmd.SetOut(os.Stdout)
+		cmd.Usage()
+		return
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	cli := common.MasterClient()
+	resp, err := cli.GetLeader(ctx, &pb.GetLeaderRequest{})
+	if err != nil {
+		common.PrintLines("get leader failed, error:\n%v", errors.ErrorStack(err))
+		return
+	}
+
+	common.PrettyPrintResponse(resp)
+}

dm/master/server.go

@@ -1559,3 +1559,24 @@ func (s *Server) getSourceRespsAfterOperation(ctx context.Context, taskName stri
 	wg.Wait()
 	return sortCommonWorkerResults(sourceRespCh)
 }
+
+// GetLeader get master leader
+func (s *Server) GetLeader(ctx context.Context, req *pb.GetLeaderRequest) (*pb.GetLeaderResponse, error) {
+	log.L().Info("", zap.Stringer("payload", req), zap.String("request", "GetLeader"))
+
+	_, leaderID, addr, err := s.election.LeaderInfo(ctx)
+
+	if err != nil {
+		return &pb.GetLeaderResponse{
+			Result: false,
+			Msg:    errors.ErrorStack(err),
+		}, nil
+	}
+
+	log.L().Info("get leader successfully", zap.String("leaderId", leaderID))
+	return &pb.GetLeaderResponse{
+		Result: true,
+		Name:   leaderID,
+		Addr:   addr,
+	}, nil
+}

dm/master/server_test.go

@@ -1141,3 +1141,86 @@ func mockRevelantWorkerClient(mockWorkerClient *pbmock.MockWorkerClient, taskNam
 		},
 	).Return(queryResp, nil).MaxTimes(maxRetryNum)
 }
+
+func (t *testMaster) TestGetLeader(c *check.C) {
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+	// create a new cluster
+	cfg1 := NewConfig()
+	c.Assert(cfg1.Parse([]string{"-config=./dm-master.toml"}), check.IsNil)
+	cfg1.Name = "dm-master-1"
+	cfg1.DataDir = c.MkDir()
+	cfg1.MasterAddr = tempurl.Alloc()[len("http://"):]
+	cfg1.PeerUrls = tempurl.Alloc()
+	cfg1.AdvertisePeerUrls = cfg1.PeerUrls
+	cfg1.InitialCluster = fmt.Sprintf("%s=%s", cfg1.Name, cfg1.AdvertisePeerUrls)
+
+	s1 := NewServer(cfg1)
+	c.Assert(s1.Start(ctx), check.IsNil)
+
+	// wait the first one become the leader
+	c.Assert(utils.WaitSomething(30, 100*time.Millisecond, func() bool {
+		return s1.election.IsLeader()
+	}), check.IsTrue)
+
+	{
+		res, err := s1.GetLeader(ctx, &pb.GetLeaderRequest{})
+		c.Assert(err, check.IsNil)
+		c.Assert(res.Name, check.Equals, cfg1.Name)
+		c.Assert(res.Addr, check.Equals, cfg1.AdvertiseAddr)
+	}
+
+	// join to an existing cluster
+	cfg2 := NewConfig()
+	c.Assert(cfg2.Parse([]string{"-config=./dm-master.toml"}), check.IsNil)
+	cfg2.Name = "dm-master-2"
+	cfg2.DataDir = c.MkDir()
+	cfg2.MasterAddr = tempurl.Alloc()[len("http://"):]
+	cfg2.PeerUrls = tempurl.Alloc()
+	cfg2.AdvertisePeerUrls = cfg2.PeerUrls
+	cfg2.Join = cfg1.MasterAddr // join to an existing cluster
+
+	s2 := NewServer(cfg2)
+	c.Assert(s2.Start(ctx), check.IsNil)
+	defer s2.Close()
+
+	{
+		res, err := s1.GetLeader(ctx, &pb.GetLeaderRequest{})
+		c.Assert(err, check.IsNil)
+		c.Assert(res.Name, check.Equals, cfg1.Name)
+		c.Assert(res.Addr, check.Equals, cfg1.AdvertiseAddr)
+	}
+	{
+		res, err := s2.GetLeader(ctx, &pb.GetLeaderRequest{})
+		c.Assert(err, check.IsNil)
+		c.Assert(res.Name, check.Equals, cfg1.Name)
+		c.Assert(res.Addr, check.Equals, cfg1.AdvertiseAddr)
+	}
+
+	s1.Close()
+	{
+		res, err := s2.GetLeader(ctx, &pb.GetLeaderRequest{})
+		c.Assert(err, check.IsNil)
+		c.Assert(res.Name, check.Equals, "")
+		c.Assert(res.Addr, check.Equals, "")
+	}
+
+	/*
+		It seems that if we kill leader in 2 masters cluster,
+		the second one wouldn't be the leader so follow cases would not be passed.
+		But I fail to create 3 masters cluster...
+
+		// wait the second one become the leader
+		c.Assert(utils.WaitSomething(30, 100*time.Millisecond, func() bool {
+			return s2.election.IsLeader()
+		}), check.IsTrue)
+
+		{
+			res, err := s2.GetLeader(ctx, &pb.GetLeaderRequest{})
+			c.Assert(err, check.IsNil)
+			c.Assert(res.Name, check.Equals, cfg2.Name)
+			c.Assert(res.Addr, check.Equals, cfg2.AdvertiseAddr)
+		}
+
+	*/
+}