Add downgrade commands

etcdctl/README.md

@@ -1083,6 +1083,47 @@ echo ${transferee_id}
 # Leadership transferred from 45ddc0e800e20b93 to c89feb932daef420
 ```
 
+### DOWNGRADE \<subcommand\>
+
+Downgrade provides commands to downgrade cluster version
+
+### DOWNGRADE VALIDATE \<TARGET_VERSION\>
+
+DOWNGRADE VALIDATE validate downgrade capability before starting downgrade
+
+#### Example
+
+```bash
+./etcdctl downgrade validate 3.5.0
+Downgrade validate success, cluster version 3.6.0
+
+./etcdctl downgrade validate 3.4.0
+Error: etcdserver: invalid downgrade target version
+
+```
+
+### DOWNGRADE ENABLE \<TARGET_VERSION\>
+
+DOWNGRADE ENABLE starts a downgrade action to cluster
+
+#### Example
+
+```bash
+./etcdctl downgrade enable 3.5.0
+Downgrade enable success, cluster version 3.6.0
+```
+
+### DOWNGRADE CANCEL \<TARGET_VERSION\>
+
+DOWNGRADE CANCEL cancels the ongoing downgrade action to cluster
+
+#### Example
+
+```bash
+./etcdctl downgrade cancel
+Downgrade cancel success, cluster version 3.6.0
+```
+
 ## Concurrency commands
 
 ### LOCK [options] \<lockname\> [command arg1 arg2 ...]

etcdctl/ctlv3/command/downgrade_command.go

@@ -0,0 +1,135 @@
+// Copyright 2016 The etcd Authors
+//
+// 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,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package command
+
+import (
+	"errors"
+	"github.com/spf13/cobra"
+	pb "go.etcd.io/etcd/api/v3/etcdserverpb"
+	"go.etcd.io/etcd/pkg/v3/cobrautl"
+)
+
+// NewDowngradeCommand returns the cobra command for "downgrade".
+func NewDowngradeCommand() *cobra.Command {
+	dc := &cobra.Command{
+		Use:   "downgrade <TARGET_VERSION>",
+		Short: "Downgrade related commands",
+	}
+
+	dc.AddCommand(NewDowngradeValidateCommand())
+	dc.AddCommand(NewDowngradeEnableCommand())
+	dc.AddCommand(NewDowngradeCancelCommand())
+
+	return dc
+}
+
+// NewDowngradeValidateCommand returns the cobra command for "downgrade validate".
+func NewDowngradeValidateCommand() *cobra.Command {
+	cc := &cobra.Command{
+		Use:   "validate <TARGET_VERSION>",
+		Short: "Validate downgrade capability before starting downgrade",
+
+		Run: downgradeValidateCommandFunc,
+	}
+	return cc
+}
+
+// NewDowngradeEnableCommand returns the cobra command for "downgrade enable".
+func NewDowngradeEnableCommand() *cobra.Command {
+	cc := &cobra.Command{
+		Use:   "enable <TARGET_VERSION>",
+		Short: "Start a downgrade action to cluster",
+
+		Run: downgradeEnableCommandFunc,
+	}
+	return cc
+}
+
+// NewDowngradeCancelCommand returns the cobra command for "downgrade cancel".
+func NewDowngradeCancelCommand() *cobra.Command {
+	cc := &cobra.Command{
+		Use:   "cancel",
+		Short: "Cancel the ongoing downgrade action to cluster",
+
+		Run: downgradeCancelCommandFunc,
+	}
+	return cc
+}
+
+// downgradeValidateCommandFunc executes the "downgrade validate" command.
+func downgradeValidateCommandFunc(cmd *cobra.Command, args []string) {
+	if len(args) < 1 {
+		cobrautl.ExitWithError(cobrautl.ExitBadArgs, errors.New("TARGET_VERSION not provided"))
+	}
+	if len(args) > 1 {
+		cobrautl.ExitWithError(cobrautl.ExitBadArgs, errors.New("too many arguments"))
+	}
+	targetVersion := args[0]
+
+	if len(targetVersion) == 0 {
+		cobrautl.ExitWithError(cobrautl.ExitBadArgs, errors.New("member peer urls not provided"))
+	}
+
+	ctx, cancel := commandCtx(cmd)
+	cli := mustClientFromCmd(cmd)
+
+	resp, err := cli.Downgrade(ctx, int32(pb.DowngradeRequest_VALIDATE), targetVersion)
+	cancel()
+	if err != nil {
+		cobrautl.ExitWithError(cobrautl.ExitError, err)
+	}
+
+	display.DowngradeValidate(*resp)
+}
+
+// downgradeEnableCommandFunc executes the "downgrade enable" command.
+func downgradeEnableCommandFunc(cmd *cobra.Command, args []string) {
+	if len(args) < 1 {
+		cobrautl.ExitWithError(cobrautl.ExitBadArgs, errors.New("TARGET_VERSION not provided"))
+	}
+	if len(args) > 1 {
+		cobrautl.ExitWithError(cobrautl.ExitBadArgs, errors.New("too many arguments"))
+	}
+	targetVersion := args[0]
+
+	if len(targetVersion) == 0 {
+		cobrautl.ExitWithError(cobrautl.ExitBadArgs, errors.New("member peer urls not provided"))
+	}
+
+	ctx, cancel := commandCtx(cmd)
+	cli := mustClientFromCmd(cmd)
+
+	resp, err := cli.Downgrade(ctx, int32(pb.DowngradeRequest_ENABLE), targetVersion)
+	cancel()
+	if err != nil {
+		cobrautl.ExitWithError(cobrautl.ExitError, err)
+	}
+
+	display.DowngradeEnable(*resp)
+}
+
+// downgradeCancelCommandFunc executes the "downgrade cancel" command.
+func downgradeCancelCommandFunc(cmd *cobra.Command, args []string) {
+	ctx, cancel := commandCtx(cmd)
+	cli := mustClientFromCmd(cmd)
+
+	resp, err := cli.Downgrade(ctx, int32(pb.DowngradeRequest_CANCEL), "")
+	cancel()
+	if err != nil {
+		cobrautl.ExitWithError(cobrautl.ExitError, err)
+	}
+
+	display.DowngradeCancel(*resp)
+}

etcdctl/ctlv3/command/printer.go

@@ -50,6 +50,10 @@ type printer interface {
 	EndpointHashKV([]epHashKV)
 	MoveLeader(leader, target uint64, r v3.MoveLeaderResponse)
 
+	DowngradeValidate(r v3.DowngradeResponse)
+	DowngradeEnable(r v3.DowngradeResponse)
+	DowngradeCancel(r v3.DowngradeResponse)
+
 	Alarm(v3.AlarmResponse)
 
 	RoleAdd(role string, r v3.AuthRoleAddResponse)
@@ -118,6 +122,9 @@ func (p *printerRPC) Alarm(r v3.AlarmResponse)           { p.p((*pb.AlarmRespons
 func (p *printerRPC) MoveLeader(leader, target uint64, r v3.MoveLeaderResponse) {
 	p.p((*pb.MoveLeaderResponse)(&r))
 }
+func (p *printerRPC) DowngradeValidate(r v3.DowngradeResponse)   { p.p((*pb.DowngradeResponse)(&r)) }
+func (p *printerRPC) DowngradeEnable(r v3.DowngradeResponse)     { p.p((*pb.DowngradeResponse)(&r)) }
+func (p *printerRPC) DowngradeCancel(r v3.DowngradeResponse)     { p.p((*pb.DowngradeResponse)(&r)) }
 func (p *printerRPC) RoleAdd(_ string, r v3.AuthRoleAddResponse) { p.p((*pb.AuthRoleAddResponse)(&r)) }
 func (p *printerRPC) RoleGet(_ string, r v3.AuthRoleGetResponse) { p.p((*pb.AuthRoleGetResponse)(&r)) }
 func (p *printerRPC) RoleDelete(_ string, r v3.AuthRoleDeleteResponse) {
@@ -163,6 +170,9 @@ func (p *printerUnsupported) EndpointStatus([]epStatus) { p.p(nil) }
 func (p *printerUnsupported) EndpointHashKV([]epHashKV) { p.p(nil) }
 
 func (p *printerUnsupported) MoveLeader(leader, target uint64, r v3.MoveLeaderResponse) { p.p(nil) }
+func (p *printerUnsupported) DowngradeValidate(r v3.DowngradeResponse)                  { p.p(nil) }
+func (p *printerUnsupported) DowngradeEnable(r v3.DowngradeResponse)                    { p.p(nil) }
+func (p *printerUnsupported) DowngradeCancel(r v3.DowngradeResponse)                    { p.p(nil) }
 
 func makeMemberListTable(r v3.MemberListResponse) (hdr []string, rows [][]string) {
 	hdr = []string{"ID", "Status", "Name", "Peer Addrs", "Client Addrs", "Is Learner"}

etcdctl/ctlv3/command/printer_simple.go

@@ -176,6 +176,16 @@ func (s *simplePrinter) MoveLeader(leader, target uint64, r v3.MoveLeaderRespons
 	fmt.Printf("Leadership transferred from %s to %s\n", types.ID(leader), types.ID(target))
 }
 
+func (s *simplePrinter) DowngradeValidate(r v3.DowngradeResponse) {
+	fmt.Printf("Downgrade validate success, cluster version %s", r.Version)
+}
+func (s *simplePrinter) DowngradeEnable(r v3.DowngradeResponse) {
+	fmt.Printf("Downgrade enable success, cluster version %s", r.Version)
+}
+func (s *simplePrinter) DowngradeCancel(r v3.DowngradeResponse) {
+	fmt.Printf("Downgrade cancel success, cluster version %s", r.Version)
+}
+
 func (s *simplePrinter) RoleAdd(role string, r v3.AuthRoleAddResponse) {
 	fmt.Printf("Role %s created\n", role)
 }

etcdctl/ctlv3/ctl.go

@@ -97,6 +97,7 @@ func init() {
 		command.NewRoleCommand(),
 		command.NewCheckCommand(),
 		command.NewCompletionCommand(),
+		command.NewDowngradeCommand(),
 	)
 }