go.etcd.io/etcd@v3.3.27+incompatible/etcdctl/ctlv3/command/move_leader_command.go (about)

     1  // Copyright 2017 The etcd Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package command
    16  
    17  import (
    18  	"fmt"
    19  	"strconv"
    20  
    21  	"github.com/coreos/etcd/clientv3"
    22  	"github.com/spf13/cobra"
    23  )
    24  
    25  // NewMoveLeaderCommand returns the cobra command for "move-leader".
    26  func NewMoveLeaderCommand() *cobra.Command {
    27  	cmd := &cobra.Command{
    28  		Use:   "move-leader <transferee-member-id>",
    29  		Short: "Transfers leadership to another etcd cluster member.",
    30  		Run:   transferLeadershipCommandFunc,
    31  	}
    32  	return cmd
    33  }
    34  
    35  // transferLeadershipCommandFunc executes the "compaction" command.
    36  func transferLeadershipCommandFunc(cmd *cobra.Command, args []string) {
    37  	if len(args) != 1 {
    38  		ExitWithError(ExitBadArgs, fmt.Errorf("move-leader command needs 1 argument"))
    39  	}
    40  	target, err := strconv.ParseUint(args[0], 16, 64)
    41  	if err != nil {
    42  		ExitWithError(ExitBadArgs, err)
    43  	}
    44  
    45  	c := mustClientFromCmd(cmd)
    46  	eps := c.Endpoints()
    47  	c.Close()
    48  
    49  	ctx, cancel := commandCtx(cmd)
    50  
    51  	// find current leader
    52  	var leaderCli *clientv3.Client
    53  	var leaderID uint64
    54  	for _, ep := range eps {
    55  		cfg := clientConfigFromCmd(cmd)
    56  		cfg.endpoints = []string{ep}
    57  		cli := cfg.mustClient()
    58  		resp, serr := cli.Status(ctx, ep)
    59  		if serr != nil {
    60  			ExitWithError(ExitError, serr)
    61  		}
    62  
    63  		if resp.Header.GetMemberId() == resp.Leader {
    64  			leaderCli = cli
    65  			leaderID = resp.Leader
    66  			break
    67  		}
    68  		cli.Close()
    69  	}
    70  	if leaderCli == nil {
    71  		ExitWithError(ExitBadArgs, fmt.Errorf("no leader endpoint given at %v", eps))
    72  	}
    73  
    74  	var resp *clientv3.MoveLeaderResponse
    75  	resp, err = leaderCli.MoveLeader(ctx, target)
    76  	cancel()
    77  	if err != nil {
    78  		ExitWithError(ExitError, err)
    79  	}
    80  
    81  	display.MoveLeader(leaderID, target, *resp)
    82  }