refactor: refactoring of code to meet all go lint requirements

pkg/azure/azure.go

@@ -55,12 +55,12 @@ func createClient(conf Config) (*azblob.Client, error) {
 	// Create the service URL
 	credential, err := azblob.NewSharedKeyCredential(conf.AccountName, conf.AccountKey)
 	if err != nil {
-		log.Fatalf("Failed to create credential: %v", err)
+		return nil, fmt.Errorf("failed to create service URL")
 	}
 	serviceURL := fmt.Sprintf("https://%s.blob.core.windows.net/", conf.AccountName)
 	client, err := azblob.NewClientWithSharedKeyCredential(serviceURL, credential, nil)
 	if err != nil {
-		log.Fatalf("Failed to create client: %v", err)
+		return nil, fmt.Errorf("failed to create client")
 	}
 	return client, nil
 }

pkg/ftp/ftp.go

@@ -82,14 +82,24 @@ func NewStorage(conf Config) (pkg.Storage, error) {
 // Copy copies file to the remote server
 func (s ftpStorage) Copy(fileName string) error {
 	ftpClient := s.client
-	defer ftpClient.Quit()
+	defer func(ftpClient *ftp.ServerConn) {
+		err := ftpClient.Quit()
+		if err != nil {
+			return
+		}
+	}(ftpClient)
 
 	filePath := filepath.Join(s.LocalPath, fileName)
 	file, err := os.Open(filePath)
 	if err != nil {
 		return fmt.Errorf("failed to open file %s: %w", fileName, err)
 	}
-	defer file.Close()
+	defer func(file *os.File) {
+		err := file.Close()
+		if err != nil {
+			return
+		}
+	}(file)
 
 	remoteFilePath := filepath.Join(s.RemotePath, fileName)
 	err = ftpClient.Stor(remoteFilePath, file)
@@ -104,21 +114,36 @@ func (s ftpStorage) Copy(fileName string) error {
 func (s ftpStorage) CopyFrom(fileName string) error {
 	ftpClient := s.client
 
-	defer ftpClient.Quit()
+	defer func(ftpClient *ftp.ServerConn) {
+		err := ftpClient.Quit()
+		if err != nil {
+			return
+		}
+	}(ftpClient)
 
 	remoteFilePath := filepath.Join(s.RemotePath, fileName)
 	r, err := ftpClient.Retr(remoteFilePath)
 	if err != nil {
 		return fmt.Errorf("failed to retrieve file %s: %w", fileName, err)
 	}
-	defer r.Close()
+	defer func(r *ftp.Response) {
+		err := r.Close()
+		if err != nil {
+			return
+		}
+	}(r)
 
 	localFilePath := filepath.Join(s.LocalPath, fileName)
 	outFile, err := os.Create(localFilePath)
 	if err != nil {
 		return fmt.Errorf("failed to create local file %s: %w", fileName, err)
 	}
-	defer outFile.Close()
+	defer func(outFile *os.File) {
+		err := outFile.Close()
+		if err != nil {
+			return
+		}
+	}(outFile)
 
 	_, err = io.Copy(outFile, r)
 	if err != nil {

pkg/local/local.go

@@ -116,7 +116,12 @@ func copyFile(src, dst string) error {
 	if err != nil {
 		return err
 	}
-	defer in.Close()
+	defer func(in *os.File) {
+		err := in.Close()
+		if err != nil {
+			return
+		}
+	}(in)
 
 	out, err := os.Create(dst)
 	if err != nil {
@@ -125,7 +130,10 @@ func copyFile(src, dst string) error {
 
 	_, err = io.Copy(out, in)
 	if err != nil {
-		out.Close()
+		err := out.Close()
+		if err != nil {
+			return err
+		}
 		return err
 	}
 	return out.Close()

pkg/local/local_test.go

@@ -45,7 +45,12 @@ func createFile(fileName, content string) ([]byte, error) {
 		fmt.Println("Error creating file:", err)
 		return nil, err
 	}
-	defer file.Close()
+	defer func(file *os.File) {
+		err := file.Close()
+		if err != nil {
+			return
+		}
+	}(file)
 
 	// Write the message to the file
 	_, err = file.WriteString(content)

pkg/s3/s3.go

@@ -94,7 +94,12 @@ func (s s3Storage) Copy(fileName string) error {
 	if err != nil {
 		return err
 	}
-	defer file.Close()
+	defer func(file *os.File) {
+		err := file.Close()
+		if err != nil {
+			return
+		}
+	}(file)
 
 	fileInfo, err := file.Stat()
 	if err != nil {
@@ -102,7 +107,10 @@ func (s s3Storage) Copy(fileName string) error {
 	}
 	objectKey := filepath.Join(s.RemotePath, fileName)
 	buffer := make([]byte, fileInfo.Size())
-	file.Read(buffer)
+	_, err = file.Read(buffer)
+	if err != nil {
+		return err
+	}
 	fileBytes := bytes.NewReader(buffer)
 	fileType := http.DetectContentType(buffer)
 
@@ -126,7 +134,13 @@ func (s s3Storage) CopyFrom(fileName string) error {
 	if err != nil {
 		return err
 	}
-	defer file.Close()
+	defer func(file *os.File) {
+		err := file.Close()
+		if err != nil {
+			fmt.Printf("Error closing file: %v\n", err)
+			return
+		}
+	}(file)
 
 	objectKey := filepath.Join(s.RemotePath, fileName)
 

pkg/ssh/ssh.go

@@ -121,7 +121,12 @@ func (s sshStorage) CopyFrom(fileName string) error {
 	if err != nil {
 		return errors.New("couldn't open the output file")
 	}
-	defer file.Close()
+	defer func(file *os.File) {
+		err := file.Close()
+		if err != nil {
+			return
+		}
+	}(file)
 
 	err = client.CopyFromRemote(context.Background(), file, filepath.Join(s.RemotePath, fileName))
 

pkg/storage.go

@@ -31,8 +31,8 @@ type Storage interface {
 	Name() string
 }
 type Backend struct {
-	//Local Path
+	// Local Path
 	LocalPath string
-	//Remote path or Destination path
+	// Remote path or Destination path
 	RemotePath string
 }