sftp binding component (#3505)

Signed-off-by: Mustafa Arslan <[email protected]>
Signed-off-by: Bernd Verst <[email protected]>
Co-authored-by: Bernd Verst <[email protected]>

Author: arslanmusta

bindings/sftp/sftp.go

@@ -0,0 +1,325 @@
+package sftp
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"reflect"
+
+	sftpClient "github.com/pkg/sftp"
+	"golang.org/x/crypto/ssh"
+	"golang.org/x/crypto/ssh/knownhosts"
+
+	"github.com/dapr/components-contrib/bindings"
+	"github.com/dapr/components-contrib/metadata"
+	"github.com/dapr/kit/logger"
+	kitmd "github.com/dapr/kit/metadata"
+)
+
+const (
+	metadataRootPath = "rootPath"
+	metadataFileName = "fileName"
+)
+
+// Sftp is a binding for file operations on sftp server.
+type Sftp struct {
+	metadata   *sftpMetadata
+	logger     logger.Logger
+	sftpClient *sftpClient.Client
+}
+
+// sftpMetadata defines the sftp metadata.
+type sftpMetadata struct {
+	RootPath              string `json:"rootPath"`
+	Address               string `json:"address"`
+	Username              string `json:"username"`
+	Password              string `json:"password"`
+	PrivateKey            []byte `json:"privateKey"`
+	PrivateKeyPassphrase  []byte `json:"privateKeyPassphrase"`
+	HostPublicKey         []byte `json:"hostPublicKey"`
+	KnownHostsFile        string `json:"knownHostsFile"`
+	InsecureIgnoreHostKey bool   `json:"insecureIgnoreHostKey"`
+}
+
+type createResponse struct {
+	FileName string `json:"fileName"`
+}
+
+type listResponse struct {
+	FileName    string `json:"fileName"`
+	IsDirectory bool   `json:"isDirectory"`
+}
+
+func NewSftp(logger logger.Logger) bindings.OutputBinding {
+	return &Sftp{logger: logger}
+}
+
+func (sftp *Sftp) Init(_ context.Context, metadata bindings.Metadata) error {
+	m, err := sftp.parseMetadata(metadata)
+	if err != nil {
+		return fmt.Errorf("failed to parse metadata: %w", err)
+	}
+
+	var auth []ssh.AuthMethod
+	var hostKeyCallback ssh.HostKeyCallback
+
+	if m.InsecureIgnoreHostKey {
+		//nolint:gosec
+		hostKeyCallback = ssh.InsecureIgnoreHostKey()
+	} else if len(m.KnownHostsFile) > 0 {
+		hostKeyCallback, err = knownhosts.New(m.KnownHostsFile)
+		if err != nil {
+			return fmt.Errorf("sftp binding error: read known host file error: %w", err)
+		}
+	} else if len(m.HostPublicKey) > 0 {
+		var hostPublicKey ssh.PublicKey
+		hostPublicKey, _, _, _, err = ssh.ParseAuthorizedKey(m.HostPublicKey)
+		if err != nil {
+			return fmt.Errorf("sftp binding error: parse host public key error: %w", err)
+		}
+
+		hostKeyCallback = ssh.FixedHostKey(hostPublicKey)
+	}
+
+	if hostKeyCallback == nil {
+		return errors.New("sftp binding error: no host validation method provided")
+	}
+
+	if len(m.PrivateKey) > 0 {
+		var signer ssh.Signer
+
+		if len(m.PrivateKeyPassphrase) > 0 {
+			signer, err = ssh.ParsePrivateKeyWithPassphrase(m.PrivateKey, m.PrivateKeyPassphrase)
+			if err != nil {
+				return fmt.Errorf("sftp binding error: parse private key error: %w", err)
+			}
+		} else {
+			signer, err = ssh.ParsePrivateKey(m.PrivateKey)
+			if err != nil {
+				return fmt.Errorf("sftp binding error: parse private key error: %w", err)
+			}
+		}
+
+		auth = append(auth, ssh.PublicKeys(signer))
+	}
+
+	if len(m.Password) > 0 {
+		auth = append(auth, ssh.Password(m.Password))
+	}
+
+	config := &ssh.ClientConfig{
+		User:            m.Username,
+		Auth:            auth,
+		HostKeyCallback: hostKeyCallback,
+	}
+
+	sshClient, err := ssh.Dial("tcp", m.Address, config)
+	if err != nil {
+		return fmt.Errorf("sftp binding error: error create ssh client: %w", err)
+	}
+
+	newSftpClient, err := sftpClient.NewClient(sshClient)
+	if err != nil {
+		return fmt.Errorf("sftp binding error: error create sftp client: %w", err)
+	}
+
+	sftp.metadata = m
+	sftp.sftpClient = newSftpClient
+
+	return nil
+}
+
+func (sftp *Sftp) parseMetadata(meta bindings.Metadata) (*sftpMetadata, error) {
+	var m sftpMetadata
+	err := kitmd.DecodeMetadata(meta.Properties, &m)
+	if err != nil {
+		return nil, err
+	}
+
+	return &m, nil
+}
+
+func (sftp *Sftp) Operations() []bindings.OperationKind {
+	return []bindings.OperationKind{
+		bindings.CreateOperation,
+		bindings.GetOperation,
+		bindings.DeleteOperation,
+		bindings.ListOperation,
+	}
+}
+
+func (sftp *Sftp) create(_ context.Context, req *bindings.InvokeRequest) (*bindings.InvokeResponse, error) {
+	metadata, err := sftp.metadata.mergeWithRequestMetadata(req)
+	if err != nil {
+		return nil, fmt.Errorf("sftp binding error: error merging metadata: %w", err)
+	}
+
+	path, err := metadata.getPath(req.Metadata)
+	if err != nil {
+		return nil, fmt.Errorf("sftp binding error: %w", err)
+	}
+
+	dir, fileName := sftpClient.Split(path)
+
+	err = sftp.sftpClient.MkdirAll(dir)
+	if err != nil {
+		return nil, fmt.Errorf("sftp binding error: error create dir %s: %w", dir, err)
+	}
+
+	file, err := sftp.sftpClient.Create(path)
+	if err != nil {
+		return nil, fmt.Errorf("sftp binding error: error create file %s: %w", path, err)
+	}
+
+	_, err = file.Write(req.Data)
+	if err != nil {
+		return nil, fmt.Errorf("sftp binding error: error write file: %w", err)
+	}
+
+	jsonResponse, err := json.Marshal(createResponse{
+		FileName: fileName,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("sftp binding error: error marshalling create response: %w", err)
+	}
+
+	return &bindings.InvokeResponse{
+		Data: jsonResponse,
+		Metadata: map[string]string{
+			metadataFileName: fileName,
+		},
+	}, nil
+}
+
+func (sftp *Sftp) list(_ context.Context, req *bindings.InvokeRequest) (*bindings.InvokeResponse, error) {
+	metadata, err := sftp.metadata.mergeWithRequestMetadata(req)
+	if err != nil {
+		return nil, fmt.Errorf("sftp binding error: error merging metadata: %w", err)
+	}
+
+	path, err := metadata.getPath(req.Metadata)
+	if err != nil {
+		return nil, fmt.Errorf("sftp binding error: %w", err)
+	}
+
+	files, err := sftp.sftpClient.ReadDir(path)
+	if err != nil {
+		return nil, fmt.Errorf("sftp binding error: error read dir %s: %w", path, err)
+	}
+
+	resp := make([]listResponse, len(files))
+
+	for i, file := range files {
+		resp[i] = listResponse{
+			FileName:    file.Name(),
+			IsDirectory: file.IsDir(),
+		}
+	}
+
+	jsonResponse, err := json.Marshal(resp)
+	if err != nil {
+		return nil, fmt.Errorf("sftp binding error: cannot marshal list to json: %w", err)
+	}
+
+	return &bindings.InvokeResponse{
+		Data: jsonResponse,
+	}, nil
+}
+
+func (sftp *Sftp) get(_ context.Context, req *bindings.InvokeRequest) (*bindings.InvokeResponse, error) {
+	metadata, err := sftp.metadata.mergeWithRequestMetadata(req)
+	if err != nil {
+		return nil, fmt.Errorf("sftp binding error: error merging metadata: %w", err)
+	}
+
+	path, err := metadata.getPath(req.Metadata)
+	if err != nil {
+		return nil, fmt.Errorf("sftp binding error: %w", err)
+	}
+
+	file, err := sftp.sftpClient.Open(path)
+	if err != nil {
+		return nil, fmt.Errorf("sftp binding error: error open file %s: %w", path, err)
+	}
+
+	b, err := io.ReadAll(file)
+	if err != nil {
+		return nil, fmt.Errorf("sftp binding error: error read file %s: %w", path, err)
+	}
+
+	return &bindings.InvokeResponse{
+		Data: b,
+	}, nil
+}
+
+func (sftp *Sftp) delete(_ context.Context, req *bindings.InvokeRequest) (*bindings.InvokeResponse, error) {
+	metadata, err := sftp.metadata.mergeWithRequestMetadata(req)
+	if err != nil {
+		return nil, fmt.Errorf("sftp binding error: error merging metadata: %w", err)
+	}
+
+	path, err := metadata.getPath(req.Metadata)
+	if err != nil {
+		return nil, fmt.Errorf("sftp binding error: %w", err)
+	}
+
+	err = sftp.sftpClient.Remove(path)
+	if err != nil {
+		return nil, fmt.Errorf("sftp binding error: error remove file %s: %w", path, err)
+	}
+
+	return nil, nil
+}
+
+func (sftp *Sftp) Invoke(ctx context.Context, req *bindings.InvokeRequest) (*bindings.InvokeResponse, error) {
+	switch req.Operation {
+	case bindings.CreateOperation:
+		return sftp.create(ctx, req)
+	case bindings.GetOperation:
+		return sftp.get(ctx, req)
+	case bindings.DeleteOperation:
+		return sftp.delete(ctx, req)
+	case bindings.ListOperation:
+		return sftp.list(ctx, req)
+	default:
+		return nil, fmt.Errorf("unsupported operation %s", req.Operation)
+	}
+}
+
+func (sftp *Sftp) Close() error {
+	return sftp.sftpClient.Close()
+}
+
+func (metadata sftpMetadata) getPath(requestMetadata map[string]string) (path string, err error) {
+	if val, ok := kitmd.GetMetadataProperty(requestMetadata, metadataFileName); ok && val != "" {
+		path = sftpClient.Join(metadata.RootPath, val)
+	} else {
+		path = metadata.RootPath
+	}
+
+	if path == "" {
+		err = errors.New("required metadata rootPath or fileName missing")
+	}
+
+	return
+}
+
+// Helper to merge config and request metadata.
+func (metadata sftpMetadata) mergeWithRequestMetadata(req *bindings.InvokeRequest) (sftpMetadata, error) {
+	merged := metadata
+
+	if val, ok := kitmd.GetMetadataProperty(req.Metadata, metadataRootPath); ok && val != "" {
+		merged.RootPath = val
+	}
+
+	return merged, nil
+}
+
+// GetComponentMetadata returns the metadata of the component.
+func (sftp *Sftp) GetComponentMetadata() (metadataInfo metadata.MetadataMap) {
+	metadataStruct := sftpMetadata{}
+	metadata.GetMetadataInfoFromStructType(reflect.TypeOf(metadataStruct), &metadataInfo, metadata.BindingType)
+	return
+}