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
15package command
16
17import (
18	"fmt"
19	"strconv"
20
21	"github.com/spf13/cobra"
22	"go.etcd.io/etcd/client/v3"
23)
24
25// NewMoveLeaderCommand returns the cobra command for "move-leader".
26func 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.
36func 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}
83