refactor: create storage interface, refactor local, s3, ftp and ssh storage

pkg/storage/ssh/ssh.go

@@ -0,0 +1,116 @@
+package ssh
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"github.com/bramvdbogaerde/go-scp"
+	"github.com/bramvdbogaerde/go-scp/auth"
+	"github.com/jkaninda/pg-bkup/pkg/storage"
+	"github.com/jkaninda/pg-bkup/utils"
+	"golang.org/x/crypto/ssh"
+	"os"
+	"path/filepath"
+)
+
+type sshStorage struct {
+	*storage.Backend
+	client scp.Client
+}
+
+// Config holds the SSH connection details
+type Config struct {
+	Host         string
+	User         string
+	Password     string
+	Port         string
+	IdentifyFile string
+	LocalPath string
+	RemotePath string
+}
+
+func createClient(conf Config) (scp.Client, error) {
+	if conf.IdentifyFile != "" && utils.FileExists(conf.IdentifyFile) {
+		clientConfig, err := auth.PrivateKey(conf.User, conf.IdentifyFile, ssh.InsecureIgnoreHostKey())
+		return scp.NewClient(fmt.Sprintf("%s:%s", conf.Host, conf.Port), &clientConfig), err
+	} else {
+		if conf.Password == "" {
+			return scp.Client{}, errors.New("SSH_PASSWORD environment variable is required if SSH_IDENTIFY_FILE is empty")
+		}
+		utils.Warn("Accessing the remote server using password, which is not recommended.")
+		clientConfig, err := auth.PasswordKey(conf.User, conf.Password, ssh.InsecureIgnoreHostKey())
+		return scp.NewClient(fmt.Sprintf("%s:%s", conf.Host, conf.Port), &clientConfig), err
+
+	}
+}
+
+func NewStorage(conf Config) (storage.Storage, error) {
+	client, err := createClient(conf)
+	if err != nil {
+		return nil, err
+	}
+	return &sshStorage{
+		client: client,
+		Backend: &storage.Backend{
+			RemotePath: conf.RemotePath,
+			LocalPath: conf.LocalPath,
+		},
+	}, nil
+}
+func (s sshStorage) Copy(fileName string) error {
+	client := s.client
+	// Connect to the remote server
+	err := client.Connect()
+	if err != nil {
+		return errors.New("couldn't establish a connection to the remote server")
+	}
+	// Open the local file
+	filePath := filepath.Join(s.LocalPath, fileName)
+	file, err := os.Open(filePath)
+	if err != nil {
+		return fmt.Errorf("failed to open file %s: %w", filePath, err)
+	}
+	defer client.Close()
+	// Copy file to the remote server
+	err = client.CopyFromFile(context.Background(), *file, filepath.Join(s.RemotePath, fileName), "0655")
+	if err != nil {
+		return fmt.Errorf("failed to copy file to remote server: %w", err)
+	}
+
+	return nil
+}
+
+// CopyFrom copies a file from the remote server to local storage
+func (s sshStorage) CopyFrom(fileName string) error {
+	// Create a new SCP client
+	client := s.client
+	// Connect to the remote server
+	err := client.Connect()
+	if err != nil {
+		return errors.New("couldn't establish a connection to the remote server")
+	}
+	// Close client connection after the file has been copied
+	defer client.Close()
+	file, err := os.OpenFile(filepath.Join(s.LocalPath, fileName), os.O_RDWR|os.O_CREATE, 0777)
+	if err != nil {
+		return errors.New("couldn't open the output file")
+	}
+	defer file.Close()
+
+	err = client.CopyFromRemote(context.Background(), file, filepath.Join(s.RemotePath, fileName))
+
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// Prune deletes old backup created more than specified days
+func (s sshStorage) Prune(retentionDays int) error {
+	utils.Info("Deleting old backup from a remote server is not implemented yet")
+	return nil
+}
+
+func (s sshStorage) Name() string {
+	return "ssh"
+}