e2e: fix ctl_v3_downgrade_test; etcdctl: update output messages

etcdctl/ctlv3/command/downgrade_command.go

@@ -28,7 +28,7 @@ func NewDowngradeCommand() *cobra.Command {
 	}
 
 	dc.AddCommand(NewDowngradeValidateCommand())
-	dc.AddCommand(NewDowngradeStartCommand())
+	dc.AddCommand(NewDowngradeEnableCommand())
 	dc.AddCommand(NewDowngradeCancelCommand())
 
 	return dc
@@ -44,8 +44,8 @@ func NewDowngradeValidateCommand() *cobra.Command {
 	return cc
 }
 
-// NewDowngradeStartCommand returns the cobra command for "downgrade start"
-func NewDowngradeStartCommand() *cobra.Command {
+// NewDowngradeEnableCommand returns the cobra command for "downgrade enable"
+func NewDowngradeEnableCommand() *cobra.Command {
 	cc := &cobra.Command{
 		Use:   "enable <targetVersion>",
 		Short: "Enable the cluster to downgrade to target version",
@@ -67,7 +67,7 @@ func NewDowngradeCancelCommand() *cobra.Command {
 // downgradeValidateCommandFunc executes the "downgrade validate" command
 func downgradeValidateCommandFunc(cmd *cobra.Command, args []string) {
 	if len(args) < 1 {
-		ExitWithError(ExitBadArgs, errors.New("target version not provided"))
+		ExitWithError(ExitBadArgs, errors.New("no target version input"))
 	}
 
 	if len(args) > 1 {
@@ -94,7 +94,7 @@ func downgradeValidateCommandFunc(cmd *cobra.Command, args []string) {
 // downgradeEnableCommandFunc executes the "downgrade start" command
 func downgradeEnableCommandFunc(cmd *cobra.Command, args []string) {
 	if len(args) < 1 {
-		ExitWithError(ExitBadArgs, errors.New("target version not provided"))
+		ExitWithError(ExitBadArgs, errors.New("no target version input"))
 	}
 
 	if len(args) > 1 {

etcdctl/ctlv3/command/printer_fields.go

@@ -229,7 +229,7 @@ func (p *fieldsPrinter) UserDelete(user string, r v3.AuthUserDeleteResponse) { p
 
 func (p *fieldsPrinter) DowngradeValidate(r v3.DowngradeResponse) {
 	p.hdr(r.Header)
-	fmt.Println("The cluster can be downgrade to target version.")
+	fmt.Println("Validate succeeded")
 	fmt.Println(`"Current cluster version" :`, r.Version)
 }
 
@@ -241,6 +241,6 @@ func (p *fieldsPrinter) DowngradeEnable(r v3.DowngradeResponse) {
 
 func (p *fieldsPrinter) DowngradeCancel(r v3.DowngradeResponse) {
 	p.hdr(r.Header)
-	fmt.Println("Current downgrade job has been cancelled.")
+	fmt.Println("Cancelled")
 	fmt.Println(`"Current cluster version" :`, r.Version)
 }

etcdctl/ctlv3/command/printer_simple.go

@@ -287,14 +287,13 @@ func (s *simplePrinter) UserList(r v3.AuthUserListResponse) {
 }
 
 func (s *simplePrinter) DowngradeValidate(r v3.DowngradeResponse) {
-	fmt.Printf("The cluster can be downgrade to target version. "+
-		"Current cluster version is %s\n", r.Version)
+	fmt.Printf("Validate succeeded. Current cluster version is %s\n", r.Version)
 }
 
 func (s *simplePrinter) DowngradeEnable(r v3.DowngradeResponse) {
 	fmt.Printf("The cluster is available to downgrade. Please wait until all servers are ready.\n")
 }
 
 func (s *simplePrinter) DowngradeCancel(r v3.DowngradeResponse) {
-	fmt.Printf("Current downgrade job has been cancelled.\n")
+	fmt.Printf("Cancelled.\n")
 }

etcdserver/api/membership/cluster.go

@@ -271,10 +271,8 @@ func (c *RaftCluster) Recover(onSet func(*zap.Logger, *semver.Version)) {
 	if c.downgrade == nil {
 		d = &Downgrade{Enabled: false}
 	} else {
-		//fmt.Println("downgrade enabled:", d.Enabled)
 		d = &Downgrade{Enabled: c.downgrade.Enabled, TargetVersion: c.downgrade.TargetVersion}
 	}
-	fmt.Println("downgrade enabled:", d.Enabled)
 	mustDetectDowngrade(c.lg, c.version, d)
 	onSet(c.lg, c.version)
 

etcdserver/api/membership/cluster_test.go

@@ -886,9 +886,6 @@ func TestMustDetectDowngrade(t *testing.T) {
 	lv = &semver.Version{Major: lv.Major, Minor: lv.Minor}
 	oneMinorHigher := &semver.Version{Major: lv.Major, Minor: lv.Minor + 1}
 	oneMinorLower := &semver.Version{Major: lv.Major, Minor: lv.Minor - 1}
-
-	fmt.Println(oneMinorHigher.String())
-	fmt.Println(oneMinorLower.String())
 	downgradeEnabledHigherVersion := &Downgrade{Enabled: true, TargetVersion: oneMinorHigher}
 	downgradeEnabledEqualVersion := &Downgrade{Enabled: true, TargetVersion: lv}
 	downgradeEnabledLowerVersion := &Downgrade{Enabled: true, TargetVersion: oneMinorLower}

etcdserver/cluster_util.go

@@ -177,9 +177,9 @@ func getVersions(lg *zap.Logger, cl *membership.RaftCluster, local types.ID, rt
 	return vers
 }
 
-// isDowngradeEnabled returns the downgrade enabled status in the given cluster.
-// If the local server or any other remote server has already enable downgrade, return true.
-// Otherwise, return false.
+// isDowngradeEnabled returns the downgrade status in the given cluster.
+// If the local server or any other remote server has already enable downgrade, return true and target version.
+// Otherwise, return false and nil.
 func isDowngradeEnabled(lg *zap.Logger, cl *membership.RaftCluster, local types.ID, rt http.RoundTripper) (bool, *semver.Version) {
 	members := cl.Members()
 	for _, m := range members {
@@ -202,8 +202,8 @@ func isDowngradeEnabled(lg *zap.Logger, cl *membership.RaftCluster, local types.
 	return false, nil
 }
 
-// getDowngradeStatus returns the downgrade enabled status of the given member
-// via its peerURLs. Returns the last error if it fails to get the version.
+// getDowngradeStatus returns the downgrade status of the given member
+// via its peerURLs. Returns the last error if it fails to get it.
 func getDowngradeStatus(lg *zap.Logger, m *membership.Member, rt http.RoundTripper) (*membership.Downgrade, error) {
 	cc := &http.Client{
 		Transport: rt,
@@ -343,8 +343,9 @@ func decideDowngradeStatus(lg *zap.Logger, targetVersion *semver.Version, vers m
 // cluster version in the range of [MinClusterVersion, Version] and no known members has a cluster version
 // out of the range.
 // We set this rule since when the local member joins, another member might be offline.
-// When cluster downgrade support is enabled, set maximum cluster version to be 1 minor version higher to
-// to allow current local member to join a cluster at 1 minor version high.
+// When cluster downgrade support is enabled, check whether the local version matches downgrade target version.
+// If yes, set maximum cluster version to be 1 minor version higher to
+// allow current local member to join a cluster at 1 minor version high.
 func isCompatibleWithCluster(lg *zap.Logger, cl *membership.RaftCluster, local types.ID, rt http.RoundTripper) bool {
 	vers := getVersions(lg, cl, local, rt)
 	minV := semver.Must(semver.NewVersion(version.MinClusterVersion))

etcdserver/server.go

@@ -2777,7 +2777,7 @@ func (s *EtcdServer) raftStatus() raft.Status {
 }
 
 func (s *EtcdServer) downgradeEnable(ctx context.Context, v string) (*pb.DowngradeResponse, error) {
-	// validate downgrade capability before starting job
+	// validate downgrade capability before starting downgrade
 	if resp, err := s.downgradeValidate(ctx, v); err != nil {
 		return resp, err
 	}

etcdserver/v3_server.go

@@ -832,7 +832,7 @@ func (s *EtcdServer) downgradeValidate(ctx context.Context, v string) (*pb.Downg
 
 	resp.Version = cv.String()
 	if cv.LessThan(*targetVersion) {
-		err = errors.New("target version is higher than current cluster version")
+		err = errors.New("target version too high")
 		return nil, err
 	}
 
@@ -842,7 +842,7 @@ func (s *EtcdServer) downgradeValidate(ctx context.Context, v string) (*pb.Downg
 	}
 	if !membership.IsVersionChangable(cv, targetVersion) {
 		err = fmt.Errorf(
-			"target version violates the downgrade policy. "+
+			"target version too small. "+
 				"the cluster can only be downgraded to %s",
 			semver.Version{Major: cv.Major, Minor: cv.Minor - 1}.String())
 		return nil, err

integration/v3_downgrade_test.go

@@ -67,7 +67,7 @@ func TestDowngradeValidate(t *testing.T) {
 			"validate downgrade against one minor version higher",
 			oneMinorHigher.String(),
 			false,
-			"target version is higher than current cluster version",
+			"target version too high",
 		},
 		{
 			"validate downgrade against one minor version lower",
@@ -79,7 +79,7 @@ func TestDowngradeValidate(t *testing.T) {
 			"validate downgrade against two minor version lower",
 			twoMinorLower.String(),
 			false,
-			"target version violates the downgrade policy",
+			"target version too small",
 		},
 		{
 			"validate downgrade against one minor version lower with patch version 1",