feat: add sftp driver (close #1466)

drivers/sftp/util.go

@@ -0,0 +1,72 @@
+package sftp
+
+import (
+	"path"
+
+	"github.com/pkg/sftp"
+	"golang.org/x/crypto/ssh"
+)
+
+// do others that not defined in Driver interface
+
+func (d *SFTP) initClient() error {
+	var auth ssh.AuthMethod
+	if d.PrivateKey != "" {
+		signer, err := ssh.ParsePrivateKey([]byte(d.PrivateKey))
+		if err != nil {
+			return err
+		}
+		auth = ssh.PublicKeys(signer)
+	} else {
+		auth = ssh.Password(d.Password)
+	}
+	config := &ssh.ClientConfig{
+		User:            d.Username,
+		Auth:            []ssh.AuthMethod{auth},
+		HostKeyCallback: ssh.InsecureIgnoreHostKey(),
+	}
+	conn, err := ssh.Dial("tcp", d.Address, config)
+	if err != nil {
+		return err
+	}
+	d.client, err = sftp.NewClient(conn)
+	return err
+}
+
+func (d *SFTP) remove(remotePath string) error {
+	f, err := d.client.Stat(remotePath)
+	if err != nil {
+		return nil
+	}
+	if f.IsDir() {
+		return d.removeDirectory(remotePath)
+	} else {
+		return d.removeFile(remotePath)
+	}
+}
+
+func (d *SFTP) removeDirectory(remotePath string) error {
+	remoteFiles, err := d.client.ReadDir(remotePath)
+	if err != nil {
+		return err
+	}
+	for _, backupDir := range remoteFiles {
+		remoteFilePath := path.Join(remotePath, backupDir.Name())
+		if backupDir.IsDir() {
+			err := d.removeDirectory(remoteFilePath)
+			if err != nil {
+				return err
+			}
+		} else {
+			err := d.removeFile(remoteFilePath)
+			if err != nil {
+				return err
+			}
+		}
+	}
+	return d.client.RemoveDirectory(remotePath)
+}
+
+func (d *SFTP) removeFile(remotePath string) error {
+	return d.client.Remove(path.Join(remotePath))
+}