fix(sftp): reconnect to server when connection was broken (close #6403)

drivers/sftp/driver.go

@@ -16,7 +16,8 @@ import (
 type SFTP struct {
 	model.Storage
 	Addition
-	client *sftp.Client
+	client                *sftp.Client
+	clientConnectionError error
 }
 
 func (d *SFTP) Config() driver.Config {
@@ -39,6 +40,9 @@ func (d *SFTP) Drop(ctx context.Context) error {
 }
 
 func (d *SFTP) List(ctx context.Context, dir model.Obj, args model.ListArgs) ([]model.Obj, error) {
+	if err := d.clientReconnectOnConnectionError(); err != nil {
+		return nil, err
+	}
 	log.Debugf("[sftp] list dir: %s", dir.GetPath())
 	files, err := d.client.ReadDir(dir.GetPath())
 	if err != nil {
@@ -51,6 +55,9 @@ func (d *SFTP) List(ctx context.Context, dir model.Obj, args model.ListArgs) ([]
 }
 
 func (d *SFTP) Link(ctx context.Context, file model.Obj, args model.LinkArgs) (*model.Link, error) {
+	if err := d.clientReconnectOnConnectionError(); err != nil {
+		return nil, err
+	}
 	remoteFile, err := d.client.Open(file.GetPath())
 	if err != nil {
 		return nil, err
@@ -62,14 +69,23 @@ func (d *SFTP) Link(ctx context.Context, file model.Obj, args model.LinkArgs) (*
 }
 
 func (d *SFTP) MakeDir(ctx context.Context, parentDir model.Obj, dirName string) error {
+	if err := d.clientReconnectOnConnectionError(); err != nil {
+		return err
+	}
 	return d.client.MkdirAll(path.Join(parentDir.GetPath(), dirName))
 }
 
 func (d *SFTP) Move(ctx context.Context, srcObj, dstDir model.Obj) error {
+	if err := d.clientReconnectOnConnectionError(); err != nil {
+		return err
+	}
 	return d.client.Rename(srcObj.GetPath(), path.Join(dstDir.GetPath(), srcObj.GetName()))
 }
 
 func (d *SFTP) Rename(ctx context.Context, srcObj model.Obj, newName string) error {
+	if err := d.clientReconnectOnConnectionError(); err != nil {
+		return err
+	}
 	return d.client.Rename(srcObj.GetPath(), path.Join(path.Dir(srcObj.GetPath()), newName))
 }
 
@@ -78,10 +94,16 @@ func (d *SFTP) Copy(ctx context.Context, srcObj, dstDir model.Obj) error {
 }
 
 func (d *SFTP) Remove(ctx context.Context, obj model.Obj) error {
+	if err := d.clientReconnectOnConnectionError(); err != nil {
+		return err
+	}
 	return d.remove(obj.GetPath())
 }
 
 func (d *SFTP) Put(ctx context.Context, dstDir model.Obj, stream model.FileStreamer, up driver.UpdateProgress) error {
+	if err := d.clientReconnectOnConnectionError(); err != nil {
+		return err
+	}
 	dstFile, err := d.client.Create(path.Join(dstDir.GetPath(), stream.GetName()))
 	if err != nil {
 		return err

drivers/sftp/util.go

@@ -4,6 +4,7 @@ import (
 	"path"
 
 	"github.com/pkg/sftp"
+	log "github.com/sirupsen/logrus"
 	"golang.org/x/crypto/ssh"
 )
 
@@ -30,6 +31,23 @@ func (d *SFTP) initClient() error {
 		return err
 	}
 	d.client, err = sftp.NewClient(conn)
+	if err == nil {
+		d.clientConnectionError = nil
+		go func(d *SFTP) {
+			d.clientConnectionError = d.client.Wait()
+		}(d)
+	}
+	return err
+}
+
+func (d *SFTP) clientReconnectOnConnectionError() error {
+	err := d.clientConnectionError
+	if err == nil {
+		return nil
+	}
+	log.Debugf("[sftp] discarding closed sftp connection: %v", err)
+	_ = d.client.Close()
+	err = d.initClient()
 	return err
 }