How to create a tarball (tar.gz) archive from files and directories in Go?

To create a tarball (tar.gz) archive from files and directories in Go, you can use the archive/tar and compress/gzip packages. The following code snippet demonstrates how to create a tarball containing multiple files and directories:

package main

import (
	"archive/tar"
	"compress/gzip"
	"io"
	"log"
	"os"
	"path/filepath"
)

func main() {
	outputFile, err := os.Create("archive.tar.gz")
	if err != nil {
		log.Fatal(err)
	}
	defer outputFile.Close()

	gzipWriter := gzip.NewWriter(outputFile)
	defer gzipWriter.Close()

	tarWriter := tar.NewWriter(gzipWriter)
	defer tarWriter.Close()

	files := []string{
		"file1.txt",
		"file2.txt",
		"directory1/",
		"directory2/",
	}

	for _, file := range files {
		if err := addFileToTarball(file, tarWriter); err != nil {
			log.Println(err)
		}
	}
}

func addFileToTarball(file string, tarWriter *tar.Writer) error {
	// Open the file or directory
	f, err := os.Open(file)
	if err != nil {
		return err
	}
	defer f.Close()

	// Get file information
	info, err := f.Stat()
	if err != nil {
		return err
	}

	// Create header for the file or directory
	header, err := tar.FileInfoHeader(info, info.Name())
	if err != nil {
		return err
	}

	// Write header to tarball
	if err := tarWriter.WriteHeader(header); err != nil {
		return err
	}

	// If the file is a regular file, write its contents
	if !info.IsDir() {
		_, err = io.Copy(tarWriter, f)
		if err != nil {
			return err
		}
	}

	// If the file is a directory, recursively add its contents
	if info.IsDir() {
		files, err := f.Readdir(-1)
		if err != nil {
			return err
		}

		for _, file := range files {
			filePath := filepath.Join(file.Name())
			if err := addFileToTarball(filePath, tarWriter); err != nil {
				log.Println(err)
			}
		}
	}

	return nil
}

In this code, you need to specify the files and directories you want to include in the tarball by populating the files slice. The addFileToTarball function is a recursive function that adds files and directories to the tarball. It uses the archive/tar package to create the tarball file structure and the compress/gzip package to compress the tarball. Finally, it writes the tarball to a file called archive.tar.gz.