shell: add lock/unlock command

weed/shell/command_fs_lock_unlock.go

@@ -0,0 +1,55 @@
+package shell
+
+import (
+	"io"
+)
+
+func init() {
+	Commands = append(Commands, &commandUnlock{})
+	Commands = append(Commands, &commandLock{})
+}
+
+// =========== Lock ==============
+type commandLock struct {
+}
+
+func (c *commandLock) Name() string {
+	return "lock"
+}
+
+func (c *commandLock) Help() string {
+	return `lock in order to exclusively manage the cluster
+
+	This is a blocking operation if there is alread another lock.
+`
+}
+
+func (c *commandLock) Do(args []string, commandEnv *CommandEnv, writer io.Writer) (err error) {
+
+	commandEnv.locker.RequestLock()
+
+	return nil
+}
+
+// =========== Unlock ==============
+
+type commandUnlock struct {
+}
+
+func (c *commandUnlock) Name() string {
+	return "unlock"
+}
+
+func (c *commandUnlock) Help() string {
+	return `unlock the cluster-wide lock
+
+`
+}
+
+func (c *commandUnlock) Do(args []string, commandEnv *CommandEnv, writer io.Writer) (err error) {
+
+	commandEnv.locker.ReleaseLock()
+
+	return nil
+}
+

weed/shell/exclusive_locker.go

@@ -36,7 +36,7 @@ func (l *ExclusiveLocker) GetToken() (token int64, lockTsNs int64) {
 	return atomic.LoadInt64(&l.token), atomic.LoadInt64(&l.lockTsNs)
 }
 
-func (l *ExclusiveLocker) Lock() {
+func (l *ExclusiveLocker) RequestLock() {
 	// retry to get the lease
 	for {
 		if err := l.masterClient.WithClient(func(client master_pb.SeaweedClient) error {
@@ -69,6 +69,7 @@ func (l *ExclusiveLocker) Lock() {
 				if err == nil {
 					atomic.StoreInt64(&l.token, resp.Token)
 					atomic.StoreInt64(&l.lockTsNs, resp.LockTsNs)
+					// println("ts", l.lockTsNs, "token", l.token)
 				}
 				return err
 			}); err != nil {
@@ -83,7 +84,7 @@ func (l *ExclusiveLocker) Lock() {
 
 }
 
-func (l *ExclusiveLocker) Unlock() {
+func (l *ExclusiveLocker) ReleaseLock() {
 	l.isLocking = false
 	l.masterClient.WithClient(func(client master_pb.SeaweedClient) error {
 		client.ReleaseAdminToken(context.Background(), &master_pb.ReleaseAdminTokenRequest{